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Abstract
A well-designed runner and gating system is very important to secure good quality die castings through providing a homogenous mould filling pattern. Numerical simulation is a cost-effective tool in the design of runner and gating systems to visibly analyse the mould filling process. A thin-walled magnesium telecommunication part was selected to be hot chamber die cast and a numerical simulation technique was applied for the optimisation of the runner and gating. Two types of runner and gating systems were designed and analysed. A preliminary design with a split gating system led to a swirling filling pattern and insufficient central flow, which prematurely closed the edges and left the last filled areas falling into the inner portion of the part. It resulted in a high possibility of air entrapment in the casting and the design was not proper for the part. The design was improved by using a continuous gating system and a bigger size runner. The gate area was increased and the gating speed was slightly reduced. Numerical simulation showed that the new design provided a homogenous mould filling pattern with the last filled areas being located at the upper edge of the part, where overflows and vents were conveniently attached. For the study, die inserts for both designs were fabricated. A series of casting experiments were conducted. The short shot filling tests proved that the simulation results matched the actual casting results very well. Good quality thin-walled telecommunication parts with sound microstructure were produced based on this optimised runner and gating system.
... The cross-section, position, and direction of the gate during centrifugal casting are designed to generate products with minimal porosity. Gate shapes that often used are rectangular [10][11][12][13][14] and circular [14][15] cross-section with perpendicular [10][11][12][13][14] and oblique [14] toward the mold cavity. The circular cross-section of the gate has a higher molten metal filling speed rather than the rectangular one [10]. ...
... The cross-section, position, and direction of the gate during centrifugal casting are designed to generate products with minimal porosity. Gate shapes that often used are rectangular [10][11][12][13][14] and circular [14][15] cross-section with perpendicular [10][11][12][13][14] and oblique [14] toward the mold cavity. The circular cross-section of the gate has a higher molten metal filling speed rather than the rectangular one [10]. ...
... Gate with θ of 90º is perpendicular toward the runner. This direction is the most widely used in casting [10][11][12][13][14]. The pressure and velocity of molten metal when entering the mold in this direction is determined by centrifugal force. ...
Oblique gate direction in different angles was hardly applied in centrifugal casting. The purpose of this research was to determine the effects of oblique gate direction in centrifugal casting on density, porosity, roughness, and microstructures in the artificial lumbar disc model. The angles of the oblique gate were ranged from 30º to 150º toward to the runner. The sharp turn of the gate would cause retardations and losses friction that decreased the pressure in molten metal. This process caused the porosity and the surface roughness decreased while the density increased. The product in which the oblique gate direction was the same with the mold rotation was better than the one in the opposite direction. The tangential forces would increase the forces acting on molten metal when entered the mold with the oblique gate direction that same with the mold rotation. Gate with the θ of 90º was the most widely used, but the product was better to use the gate with the θ of 60º than the product with the θ of 90º. Hence, to obtain an artificial lumbar disc model with less porosity, high density, and smooth surface, the oblique gate of 60º should be applied.
... In normal circumstances, metal feeding from a single gate is sufficient to properly feed the die-cavity. In the past, a number of computer-aided systems for die-casting die design have been proposed by the researchers [1][2][3][4][5][6]. The application of these systems is limited to the die-casting parts requiring single gate. ...
... Design of a gating system is not finalized until filling conditions for the given die-casting part are simulated. Therefore, many researchers [2,[30][31][32][33][34][35][36][37][38][39] focus their attention on filling simulation for optimizing the filling conditions using different approaches and application. Hu et al. [2] employ a numerical simulation technique to design and optimize gating-system design for thin wall die-cast components. ...
... Therefore, many researchers [2,[30][31][32][33][34][35][36][37][38][39] focus their attention on filling simulation for optimizing the filling conditions using different approaches and application. Hu et al. [2] employ a numerical simulation technique to design and optimize gating-system design for thin wall die-cast components. The system uses a pre-designed CAD model of the die-cavity and the gatingsystem prepared in CASTFLOW to simulate the filling process. ...
Current practices in the industry require significant involvement of die-casting experts who have to consider industry best practices and knowledge of process physics besides reference to a number of databases is also required making it very time consuming and cumbersome exercise. The die-casting industry therefore requires a system that could help relieve the die-casting expert from manual and time consuming tasks to design a good gating system. A computer-aided system for multi-gate gating system design for die-casting die is presented in this paper. The working of the system is supported by part, process, machine, and material information which is called input information. The system works in three major steps called modules of the system. The first module deals with the determination of die-casting process parameters. This module helps the user in determination of cavity fill time, gate velocity, and selection of die-casting machine automatically from the input information. The second module deals with the computer-aided determination of gating system parameters like gate thickness, gate length, runner length etc., by using input information. The last module of the system uses the parameters obtained from the second module to generate CAD models of the gating system by updating gating system features from feature library. The system was implemented in MATLAB. The proposed system is capable of designing gating system for die-casting parts requiring multiple gates. The system has been tested on example die-casting parts, and the results obtained from the system are as per industry practice.
... The performance of thin wall caste products got affected by the shrinkage problem which was caused due to the parameters like mould temperature, melt temperature and injection velocity. A significant improvement of 83% and 63% of reduction in dimensional shrinkage was achieved through the proper direction of metal flow in transverse and longitudinal direction [33]. The hot chamber die casting thin wall magnesium telecommunication part was designed with two different types of runner and gating systems using preliminary and new design. ...
... The hot chamber die casting thin wall magnesium telecommunication part was designed with two different types of runner and gating systems using preliminary and new design. This is shown in Fig.7 Fig. 7. Thin-walled magnesium telecommunication part-Mould filling simulation and short filling test [33]. The various aspect of the performance of aluminum alloy C355.0 material [35] were studied using three different casting processes (sand, die and centrifugal casting). ...
... The flexure strength and frequency of porosity defects were also affected by the geometry of the gating system. It was shown that optimum gating design could reduce the turbulence in the melt flow and minimize casting defects [23] .The main problems caused by improper gating are air entrapment, sand inclusion, entrained aluminium oxide film, cuts, washes, low casting yield and dross [23,24]. From these studies it is clear that an understanding of the gating system is essential for the production of defect free castings. ...
... The flexure strength and frequency of porosity defects were also affected by the geometry of the gating system. It was shown that optimum gating design could reduce the turbulence in the melt flow and minimize casting defects [23] .The main problems caused by improper gating are air entrapment, sand inclusion, entrained aluminium oxide film, cuts, washes, low casting yield and dross [23,24]. From these studies it is clear that an understanding of the gating system is essential for the production of defect free castings. ...
Foundry practice have existed in Nigeria for centuries. However, for the development of the practice, know-how and skills must be developed. Personnel must be trained at all levels. In this study, the practices in foundries of research and academic institutions involved in foundry within Lagos state were investigated. Investigations were carried out by on-site study of the foundries and also by means of questionnaires investigating various aspects of foundry practice. From responses obtained, it was shown that the capacity of foundries to produce technically sound castings is very low. Simple steps capable of increasing the quality and reproducibility of the castings were suggested. It was concluded that students’ learning and local foundry practice can be enhanced by upgrading foundries in research and educational institutions to current global best practices.
... The purpose of gating system design in centrifugal casting is to get the product DOI with minimal defects such as porosity. Porosity can occur due to the trapped gas or shrinkage during the cooling process [5][6][7]. Shrinkage control is carried out to produce defect-free products [8]. Modifications and trial errors of gating system design are less efficient and high cost to acquire good quality products. ...
... Therefore, computer simulation is sufficient to be used to plan the gating system design. The simulation results show the suitability with experimental data such as liquid solidification, porosity area, trapped gas, and filling behavior occurred in the foundry process [6,[9][10][11]. The direction, position, and cross-section of gating system design on centrifugal casting are made to get products with minimal shrinkage porosity. Gate shapes that often used are circular [4], rectangular [10,[12][13][14], and hexagonal [10] cross-section with perpendicular direction to the mold. ...
p class="AMSmaintext">Shape and direction of gate in centrifugal casting affected the microstructures and defects in castings. The purpose of this research was to determine the effects of gate shape and direction in centrifugal casting toward on porosity, density, roughness, and microstructures on the artificial lumbar disc model. The main shapes of the gate were circular and rectangular cross-section. The circular cross-section gate shape was used for two different directions of artificial lumbar discs; vertical, and horizontal. Furthermore, the rectangular cross-section gate shape consisted of three different directions; oblique clockwise, oblique counter-clockwise and perpendicular towards the mold. The rotational mold was conducted at a speed of 60 rpm. The results showed that the rectangular cross-section gate shape with the oblique direction same with the rotation of the mold produced artificial lumbar disc model that had the smallest porosity area among the other directions. It was the best shape and direction of the gate among the others which had the smallest porosity area (0,68%), highest density (4,517 g/cm3), and smoothest roughness (8,76 µm). In the sub-surface, the microstructure of α-case was formed. The thickness and hardness of the α-case in this design were 50-100 µm and 760 VHN, respectively. Hence, the rectangular cross-section gate shape with the oblique direction same with the rotation of the mold was appropriate to be applied in the manufacture of an artificial lumbar disc model.</p
... Many efforts have been done to investigate the effect of gating system on the fluid flow path into the mold [2 , 3]. It was found that an appropriate gating system design can reduce the molten metal turbulence during the filling step, minimize gas entrapment, reduce the amount of sand and slag inclusions and also oxide films defects (bifilms) [4]. ...
... • Choke area: [7] Ac = W / ρ t C √2gHp (4) Ac (m 2 ), C= discharge coefficient (0.8), g= acceleration of gravity (9.81 m/s 2 ), Hp (m) ...
Applying appropriate gating system for producing a cast part without any serious problem and casting defects has been a real challenge. Defects such as; bifilms and gas entrapment, porosity, sand erosion and wash are the main problems to tackle with in the process of casting. In this paper, the susceptibility of common and new gating systems for gravity casting of a gray cast iron thin plate in green sand are investigated, using the simulation approach. Four classes of gating systems including; top, side, bottom and slope pour were designed based on the generally accepted equations in the literature. ProCast (version 2016) has been used to simulate the casting process for the aforementioned designs. Also, an innovative gating system, benefited from applying chillers, introduced and examined. The simulation variables were selected based on the closest conditions to the real process. According to the results, the system with chiller and the slope gating system are the most effective gating systems, leading to the minimum defects and maximum quality of cast parts comparing to the other ones. However, the chill-used system is not easily applicable in casting industry, but the slope gating system can be performed as the most effective gating system to cast a thin plate of gray cast iron and possibly other alloys.
... Similar work and techniques are also reported in Kuo et al. [8]. [9] studied and inspected the influence of different gating system over continuous system. They carried out numerical simulations and proved that split gate system leads to insufficient central flow and a swirling filling pattern, which further resulted in higher air entrapment in the casting. ...
Investigation on the effectiveness of thermo-mechanical vibration technique for the purpose of degating of casting component used in developing next generation transmission in VOLVO construction equipment AB, Eskilstuna. Sweden Abstract 1 Abstract The purpose of the thesis work given is to gain a better understanding of the degating process in high-pressure die casting components, as well as the effectiveness of the thermo-mechanical vibration technique for detaching cast components from the gating system. In addition, to evaluate and establish the most appropriate degating procedure in order to reduce labor, material costs, and processing time. In recent days, many investigators have been looking at an automated technique that can help optimize and streamline the casting process. VOLVO CE is also exploring on ways to assess and establish the most acceptable degating process in order to optimize cost towards labor, material expense, and processing time. To begin with, VOLVO CE wants to develop the full Finite Element Method (FEM) based approach prior to implementation This thesis consists of a substantial amount of numerical work, demonstrating the effectiveness of thermo-mechanical vibration technique for degating the casting high-pressure die casting component. The dynamic behavior of the component was studied in ANSYS WB where the impact of thermal loading has been taken into consideration. The component studied in this thesis is a transmission component (oil distributor) from a Volvo construction equipment, VOLVO group. It is cast in Aluminum alloy with the material composition AlSi13Fe. A oil distributor is a component which is bolted on the back side (place where electric motor is connected to the casing through shaft) of the transmission casing. Summary 2 Summary The method of HPDC is one of the most important techniques for manufacturing automobile parts and electronic parts, and one of the economical casting techniques that can manufacture complex shapes at one time. When it comes to gate system, separating cast components from the gating system is a difficult process that can cost a lot of money in terms of manpower and tools. Approaches such as the ultrasonic energy method, the fatigue damage method and some traditional methods are commonly used for disjointing the casting components. Some researchers claims that there are some limitations on the above which includes inaccurate and inefficient. To overcome this, the study has been focused towards degating process of casting component under concurrent thermos-mechanical vibration loading. This project goal is to develop a new methodology and understand the effectiveness of the thermo-mechanical vibration technique for detaching cast components from the gating system, which aims to lower labor, material expense, and processing time in the casting process. The component studied in this thesis is a transmission component (oil distributor) from a Volvo construction equipment, VOLVO group. It is cast in Aluminum alloy with the material composition AlSi13Fe. A oil distributor is a component which is bolted on the back side (place where electric motor is connected to the casing through shaft) of the transmission casing. It was proven that this method only required a relatively short cycle time of breaking the components off the casting tree and also that this method would not induce any residual stress over the cast component during the degating process.
... Nowadays, advanced computer-aided engineering (CAE) simulation has many advantages in product improvement, such as product quality, reduction of production costs, and shortening of production cycles [13][14][15]. Computer-aided engineering simulation analysis is the most effective and profitable technology for evaluating casting quality and predicting defects [16][17][18]. Casting defects are complicated to predict because it cannot check the flow of solidification trends of molten metal in the mold cavity [8] [12] [17]. Furthermore, the RMM (retained melt modulus) model helps predict the location of shrinkage cavities and then focuses on processing the locations where defects occur and using various means to make the solidification trend more ideal and continuous. ...
This study contributed to the comparison of insulation cotton configurations for the investment casting quality of industrial valve parts. Due to the complexity, parts of industrial valve bodies are usually produced by casting. However, the investment casting production process has several problems, such as shrinkage porosity. Currently, the investment casting industry uses cotton configuration to solve the problem of shrinkage porosity. Therefore, this study compared three cotton installation treatments in the mold shell to determine the optimal use of cotton. There are three schemes of the type of cotton installation on the shell that will be observed, including the triangular insulation cotton area denoted as case A installed 55-mm and case B installed 90-mm cotton on the right and left sides, and case C denoted with adding bracket arms on the upper side. In this study, we used RMM (retained melt modulus) and the finite element model to analyze the shrinkage porosity’s location and to monitor the porosity that occurred during the solidification process. The result showed that cotton could reduce shrinkage porosity by 3.30%, 1.95%, and 1.47% for case A, case B, and case C, respectively. Therefore, the best alternative is case C, add the cotton and bracket arm on the upper side, which is the optimal strategy to prevent shrinkage porosity.
... B. H. Hu et al. studied and inspected the influence of different gating system over continuous system. He carried out numerical simulations and proved that split gate system leads to insufficient central flow and a swirling filling pattern, which further resulted in the higher air entrapment in the casting [3]. ...
... Then, to alleviate the casting defects in the rotor hub casting, a better alloy design was proposed based on the simulated results to alleviate casting defects of the rotor hub casting. Hu et al [8] found that numerical simulation is a cost-effective tool in the design of runner and gating systems for visibly analyzing the mold filling process. A thin-walled magnesium telecommunication component was selected as the hotchamber die cast, and a numerical simulation technique was applied to optimize the runner and gating. ...
The brake lever for an electric multiple unit (EMU) of a train is an important supporting component that directly affects the usability and safety of EMU. In this study, the mold filling, solidification, and shrinkage processes of the brake lever of the EMU were simulated using Anycasting software, and the distributions of the mold filling speed, mold filling temperature, and shrinkage defects were analyzed. The results show that the brake lever for the EMU exhibits casting defects such as shrinkage porosity and shrinkage cavities. To eliminate these casting defects, a chilled-iron process was developed; however, the appearance of cementite increased the brittleness of the castings, which deteriorated their strength and plastic toughness. Hence, a snap-chilling sheet process was designed to fabricate the brake lever for the EMU, and a numerical simulation of the process was performed using the Anycasting software. The shrinkage defects of the castings were effectively eliminated; simultaneously, the cementite disappeared, and the microstructure of the thick parts of the brake lever showed no obvious changes. The prepared brake lever satisfied the requirements of the EMU.
... It is necessary to use technically advanced computer-aided engineering (CAE) and nondestructive testing methods in order to make the design choice. They provide various benefits, including enhanced quality, reduced expenses, and a shortened development period [13][14][15]. This strategy will assist in enhancing the accuracy of investment casting simulations by collecting data. ...
Investment casting (IC) with different insulating wool pattern and shell mold thickness is investigated for a geometrically complex vortex flow meter in this study. The primary coating consists of zircon (ZrSiO4) with colloidal silica (SiO2) binder. Zircon is regarded as a potential engineering material for high-temperature applications for its chemical stability, strong fracture resistance at higher temperature range, and low thermal expansion coefficient. The fundamental properties of the shell mold, such as mechanical property and thermal properties were experimentally validated. The modulus of rupture was found to be 5.6 ± 0.5 MPa. The Heat transfer coefficient (HTC) was calculated to be in the range of 600–900 W/(m² K). Later as the input data for numerical simulation. In addition, using a computer-aided numerical (CAE) approach and tests, this research investigated whether the thermal properties of varied layer thicknesses and insulating wool patterns may impact the formation of casting defects. The CAE simulation reveals that the initial layer thickness would result in pipe wall problems. To lessen the hot spot region, the first step is to employ different insulating wool patterns, which could reduce the probability of shrinkage forming by 17%. The second step is to increase the thickness of the mold shell to reduce the percentage of hot spots. It is calculated that the optimal design would reduce the probability of shrinkage defects by 47%. The varying thermal properties may significantly decrease the casting faults of a mass-produced vortex flow meter by altering the thickness of the shell mold. In this study, the best solution for vortex flow meter process improvement has been adopted by an IC foundry and mass-produced. The X ray inspection shows flawless results in the vortex flow meter pipe wall where defects often form, and proves the effect and feasibility of the thermal insulation improvement proposal.
... A homogeneous heat gradient and the restriction of mold erosion are achieved with correct gating, resulting in a smooth metal filling [24]. An improper gating design causes turbulence by forming an oxide film, air entrapment, dross, and sand inclusion [25][26][27][28][29][30][31]. ...
Casting is a fabrication method used to create various industrial parts with different shapes. Flaws such as shrinkage, porosity, and short metal filling can result in casting rejection. These flaws are heavily reliant on casting parameter design (gating and riser system design) and can be reduced by optimizing the casting parameter design. The development of materials with new or improved properties has long been the primary objective of materials scientists. The designing of metallic alloys for structural purposes must take strength, toughness, and formability into account to achieve the desired performance. The unique convergence of these essential characteristics that characterize high manganese steels fascinate scientists worldwide. The current work systematically investigated a gating system and riser design effect for high Manganese steel samples (bushes) to develop an understanding of the structure–property relationship. The first conventional manual calculation was performed to design the gating and riser system. Subsequently, a sophisticated simulation software called SolidCast was used to design, validate, and improve the casting parameters of the specimen. To back up the findings, confirmatory experiments were carried out. Both designs were used to make castings in order to check for flaws. The microstructural and mechanical characteristics of these materials were investigated. Visual inspection of the manually-designed castings revealed considerable shrinkage, whereas software-designed castings seemed in good shape, without the shrinkage, macroporosity, and microporosity. The microstructure of the specimens was also studied by applying optical microscopy and SEM analysis. By improving the gating and riser system with the SolidCast software, sound casting was achieved. This improved the quality of casting results with a considerable enhancement of yield strength (~32 percent), hardness (~34 percent), and tensile strength (~27 percent), which may lead to significant cost savings.
... Due to the development and industrialization of science and technology, aluminum alloys have developed in various fields. Due to recent problems involving resource shortage, energy conservation, and environmental problems, the manufacturing of cast iron and sand castings are being replaced by processes such as aluminum and high-pressure die casting (HPDC) [1,2]. ...
Due to the development and industrialization of science and technology, aluminum alloys have been developed in various fields. Recently, the government has been pursuing ways to decrease the weight and increase the recyclability of various components in order to conserve resources, energy, and the environmental. In keeping with this trend, cast iron products are being replaced by aluminum products in the foundry industry by using high-pressure die casting (HPDC). Casting layout design, relies on the experience and knowledge of mold designers in the casting industry, which proves insufficient to respond to the rapidly changing needs of the era and to increasing production costs. Designing and producing casting layouts using CAD/CAM/CAE technology has become a critical issue. Computer-Aided Engineering (CAE) technology is rapidly increasing with the development of computer software and hardware. CAE technology not only predicts defects in mass production but also performs filling or solidification analysis during the mold design stage before production, enabling optimal mold design methods. New technologies that combine the emerging casting processes of filling and solidification analysis using computer simulation with existing technology and practical experience in the field are rapidly increasing in the foundry industry. Based on empirical knowledge, the layout and design of casting products has traditionally progressed through trial and error. The solutions achieved through scientific calculation and analysis using CAE technology can save a great deal of money and time in the building of die-casting molds and in their design and fabrication. In this study, numerical analysis of household appliances (cooking grills) quickly and accurately predicts problems arising from the filling and solidification of the melted metal in the casting process, thereby ensuring the quality of the final cast product. These results can be used to quickly establish a sound casting layout with reduced production costs.
... Em termos de propriedades mecânicas, o limite de resistência, de escoamento e a ductilidade das ligas de fundição são influenciados pelo efeito do teor de liga em solução sólida e a formação de partículas de segunda fase durante a solidificação no refinamento de grãos [8], no entanto, estudos indicaram que as propriedades mecânicas do produto fundido também estão relacionadas com as velocidades do metal fundido no canal e a temperatura da matriz [9][10][11]. Zhang et al. [12], desenvolveram um método para melhorar o controle de defeitos e variação de propriedades mecânicas na fundição sob pressão da liga A380. ...
... Then, adjusting the rotational speed of more than 180 rpm can reduce the porosity [6]. The proper combination of the runner design, rotational speed, and gating system can produce a good quality of casting products [7,8]. Bimetal manufacturing technology is continuously being developed to find the required superior properties. ...
Bimetal is a combination of two dissimilar metals that form a metallurgical bond. The manufacture of bimetallic bushing by centrifugal casting has not been widely developed. There is still no recommendation for optimum temperature used in the manufacture. The aim of this research was to determine the first frozen layer temperature of the aluminum when bronze was poured to produce a well-integrated bond interface. The materials used were aluminum and bronze. Molten metal was pouring into the mold alternately. First, aluminum was poured into the mold. Then, bronze was poured gradually to form a bushing aluminum-bronze bimetallic. The temperature variations of the first frozen layer of aluminum were 27º C, 350º C, 400º C, and 450º C when bronze poured. The molten metal was poured with the filling speed of about 0.2 kg/s into a rotating sand mold. The rotational speed of the mold was 350 rpm. The result shows that the bond interface’s width increases as the first frozen layer aluminum temperature increases. As a result, interface wear and hardness are increased compared to the base metal. Hence, centrifugal casting with the first frozen layer aluminum was 450ºC recommended for aluminum-bronze bimetal bushing applications.
... Similarly, the VOF (Volumen of Fluid) method was successfully used for the same purpose in the studies carried out by Zhao et al. [26] and Hernández-Ortega et al. [27]. In the work of Hu et al. [28], experimental and numerical data were employed to predict different designs of the runner and the gating system. In further studies, CFD (Computational Fluid Dynamics) was also used to analyse the influence of acceleration parameters and the filling fraction on air entrapment in the shot sleeve [29,30] to evaluate the critical velocity in the shot sleeve [31], to carry out the thermal analysis of the pressure die-casting process [32][33][34], or to evaluate the overall process performance with CAE (Computer Aided Engineering) [35,36]. ...
A large number of material and process parameters affect both the part quality and the process performance in pressure die-casting (PDC) processes. The complex relations between most of these variables make PDC process optimisation a difficult issue which has been widely studied for many years. Although there are several analytical and numerical models to optimise certain process parameters, it is difficult to establish a specific operational configuration for PDC machines that ensures the joint optimisation of these variables. Therefore, in this study, some of these optimisation models have been implemented in a Decision Support System (DSS) that allows us to define an operational region that establishes a setup of machine parameters that ensures the manufacture of quality parts. By using this DSS, the user can set the values of the input variables related to the casting material, the die, or the casting machine. Then the corresponding calculations are made by the system and the results are expressed in terms of certain output variables such as the maximum filling time, maximum filling fraction, or the plunger velocity profile among others. The DSS allows the user to estimate the influence between input and output variables and find proper values for the input variables to achieve an optimum operational range. Consequently, improved process performance can be achieved taking into account productivity, part quality, and economic aspects.
... The continuity equation, Navier-Stokes equation, energy conservation, the volumeof-fluid (VOF) function, and k-equations were used to estimate the pressure field, velocity field, and temperature field during filling and solidification. [14][15][16][17][18]20 For each casting system, a statistical RMM model was used to evaluate the probability of cavity shrinkage formation, as follows 6,21 :M R ¼ V R =S R , V R and S R , respectively, represent the volume and surface area of isolated melt at the time that each mesh reached the critical solid fraction. A lower RMM value indicates a higher chance of shrinkage occurrence. ...
Defects in investment casting will inevitably reduce the lifetime, degrade the quality of the casting, and increase the manufacturing costs. In this paper, the potential for shrinkage porosity was numerically determined and a retained melt modulus (RMM) model was implemented to analyze highly probable regions. The proposed casting schemes of gating designs are compared by the quality of casting (shrinkage porosity) and practical feasibility in terms of small hole drilling machinability. The purpose of this study was to determine the feasible plan with the lowest PES (percentage of elements with shrinkage porosity) while promoting near-net shape casting with minimum machining cost and increasing material usage. Virtual thermo-dynamical sensors (VTDSs) were adopted in the simulations to indicate the impacts of different pattern assembly gating systems on the cooling gradient and direction of solidification. VTDSs were used in simulating and virtually monitoring the casting systems, with the aim of characterizing the rates and directions of solidification in various regions of the cast. The best-case scenario of investment casting conditions was chosen to fabricate valve housing in an investment casting foundry. The experimental results of the X-ray image differentiated nearly none of the pernicious defects that typically occurred with the proposed casting, confirming the efficacy of the proposed scheme accordingly.
... They possess many advantages such as improving quality, reducing cost, shortening development schedule. [18][19][20] CAE simulation is the most e cient and pro table technology from the perspective of quality and defect prediction for analyzing and evaluating the quality and defects of casting products. [21,22] Many previous casting research methods have chosen trial-and-error ways, often unreliable, time-consuming, and costly. ...
Defects in investment casting will inevitably reduce the lifetime and degrade the casting quality and increase manufacturing costs, accordingly. In particular, shrinkage porosity was numerically conducted, and a retained melt modulus model was implemented to analyze highly probable regions. The proposed casting schemes of gating designs are compared by quality of casting (shrinkage porosity) and practical feasibility in terms of small hole drilling machinability. The purpose of this study was to determine the feasible plan with the lowest PES (percentage of elements with shrinkage porosity) while promoting the near net shape casting with minimum machining cost and increase material usage. Virtual thermo-dynamical sensors were adopted in the simulations to indicate the impacts of different gating system of pattern assembly on the cooling gradient and direction of solidification. The best-case scenario of investment casting conditions was chosen to fabricate valve housing in an investment casting foundry. Experimental results of X-ray image differentiated nearly none of the pernicious defects that typically occurred with proposed casting, authenticating the proposed scheme's efficacy accordingly.
... One of their conclusions was bottom pouring running systems produced goods with less scatter of tensile strength and therefore increasing reliability than the products by top pouring running systems. Hu et al (Hu et al 2000) used numerical simulations to design the running and gating system and study the mould filling process. Shepel and Paolucci (Shepel and Paolucci 2002) developed a finite element model for solving the fluid and heat equations in the study of filling of three dimensional mould by using the volume of fluid (VOF) method. ...
Epoxy resins are one of the most widely used thermosetting materials, especially for transformer insulation in the electrical industry. One of the primary technologies used for manufacturing such products is based on pressure casting. Computational fluid dynamics (CFD) calculations of the mould filling stage in a pressure casting process for epoxy resin casting are carried out and presented in this paper. Two designs of a gating system are studied and their effects on the flow parameters in the mould are analyzed. The two designs being top pour and bottom pour inlet. A new solver is developed in an open source CFD framework, OpenFOAM, which incorporates the Navier–Stokes equations, energy equation including the viscous dissipation and a new isoAdvector approach for capturing the liquid-gas interface. The objective is to simulate the flow and heat transfer of epoxy resin, while being filled in the mould that is initially empty and heated to a specified temperature. Formulation was validated with experimental measurements of the classical dam breaking problem. For the resin filling problem, further verification was carried out using grid-dependent studies and temporal fill factor comparisons to experiments. In addition, instantaneous contours of volume fraction and temperature, and velocity vectors are studied to understand the flow patterns and heat transfer in the mould during the filling process. Among both the gating designs, the bottom pour was the more preferred one as it resulted in less turbulence, sloshing and it provides an easy passage for the voids to escape leading to higher fill factor. This analysis also helps in recognising the location of voids and thereby help in potentially identifying optimal process parameter settings for a more suitable mould design.
... Filling velocity has been demonstrated to dramatically affect mechanical strength and fatigue life of cast alloys due to the formation of turbulence within the mold. As melt velocity within the casting exceeds the critical velocity as defined Campbell [5] and others [6,7], the rate of formation of casting defects, such as gas pores, sand entrainment, and bifilms increases substantially [5,[8][9][10]. ...
As 3D Sand-Printing technology becomes more widely available to the casting market, the search for opportunities to take advantage of its freedom of design is critical for its rapid adoption by the casting community. This original research investigates casting design principles towards defect-free alloy Nickel-Aluminum Bronze (NAB). This is an alloy of interest for marine applications due to its corrosion resistance, mechanical strength and good castability. Numerical modeling of flow within a casting is examined, and rigging redesigns are proposed to improve casting quality by controlling flow behavior. It has been demonstrated that turbulence and filling velocity are determining factors that seriously impact casting performance due to the generation of casting defects. Among these are bifilm formations, gas and sand entrapment and cold shut. This work examines the effectiveness of mathematically designed rigging components in controlling mold filling and compares the results to a conventional casting rig. Design solutions are proposed using 3DSP that can be directly applied to casting operations of Nickel-Aluminum Bronze. The results from this study demonstrate the effectiveness of mathematically designed sprues to reduce filling velocity of Nickel-Aluminum Bronze. The procedure followed here can be extended to marine casting production environments. Findings from this study can be seamlessly transferred to castings of any geometry, alloy and pouring conditions.
... The point of metal entry into the actual casting or mould cavity is referred to as in-gate. Good quality of a cast or homogeneous mould filling has been adjudged to be dependent on a proper gating system design [21] and the gating system design needs to follow an iterative process [22] The sequential steps employed in designing the gating system for the piston cast involve: 1. Estimation of optimum pouring time of casting, 2. Calculation of sprue choke area 3. Selection of gating ratio 4. Selection of the type of gating/location 5. Calculation of runner and in-gate sizes ...
... In addition, it can increase the impact resistance of parts, reduce vibration and noise, and improve the rigidity of the parts in automotive applications, such as transmission case, engine cradle, and wheel hub. An engine cradle made of a Mg-4Al-4RE alloy is displayed in Fig. 4 (Hu et al., 2000). Parts made by magnesium alloys can be considered as a kind of green materials due to their recyclability. ...
Metallic materials are important for making multi-scale parts and structures because of their excellent mechanical properties and good formability. This article reviews several types of classic metallic materials for multi-scale structural applications, including aluminum alloys, magnesium alloys, copper alloys, titanium alloys, carbon steels, nanoprecipitation-strengthened steels, metallic glasses, and high-entropy alloys. Particular emphasis is placed on the alloy characteristics, microstructure, mechanical properties, processability, formability, and applications of these materials, aiming at providing a reference tool for material selection in multi-scale structure design and development.
... Therefore adequate care is necessary in designing gating and risering systems for improved yield of defect free castings [8]. It has been shown that good gating system design could reduce the turbulence of melt flow, air entrapment, sand inclusion, oxide film and dross [9][10][11][12][13][14]. Melt flow influences solidification time, which is an important parameter that could alter the microstructure and mechanical properties of the cast part. ...
Solidification as well as filling has great influences on the quality of cast products. In modern competitive world for increasing the quality of products these two steps draw higher attention to casting engineers. This case study is just one of the followings of the above mentioned objective. The aim of the present work is to reduce the rejection rate of cast products in a foundry shop due to casting defects in sand casting process using a computer aided simulation technique. In general conventional techniques require a larger number of trials with higher costs for checking outputs when the number of process parameters increase that can be reduced using simulation. For the simplification in this analysis grain size of sand, material quality, casting process parameters are considered uniform for all cases. Only the positional and dimensional variances are taken in considerations for defects analysis. It is found that defects such as shrinkage porosity, improper solidification, air entrapment, mould erosion are directly related with gating and feeding system design and although other process parameters are considered uniform but this defects will be changed with changing the design parameters. In this case Click2cast casting simulation software is used for mould filling and solidification analysis and it is observed that proposed gating and feeding system design improves casting yield approximately 15% more than conventional gating and feeding system. The validation of simulation is proved through experimental trials in foundry shop.
... With reference to the quality of the product and the perspective of forecasting defects, the finite element simulation is a much more efficient and economic techniques for the analysis and evaluation of the quality and defects of the products [3]. Many researchers have carried out simulation tests for the die-casting of aluminum, zinc and tin alloys in various productive sectors, mainly in the automotive's one [4,5], simplified models for simulations have also been studied, with related case studies [6,7], however a more accurate analysis of small thickness castings was analyzed only for magnesium [8], ...
The diecasting modern industries are moving towards the proof-of-concept methods based on finite element simulation (FEM), abandoning the traditional trial-and-error. Aluminum DC is a very complex process because the mold filling problems. In the new design production system approach, the FEM simulations play an important role, virtually recreating the entire casting phases. In this research, simulations were carried out using a commercial software to optimize the gates and runner’s design of a thin panel component in G-AlSi13Fe aluminum alloy actually realized in AA3004 sheet metal formed. Filling analysis was used to define the gate’s size, its correct positioning and the runner system design.
... Additionally, during intensification the majority of air entrapment resulting from fluid flow in the shot sleeve is compressed to a considerable small size under the applied pressure. The contribution of air entrapment to the final porosity content is a key factor in assessing the suitability of a cast component for heat treatment, in the presence of gas porosity blistering will occur during solution treatment and the component will be scrapped [11][12][13].Shrinkage porosity forms in the final stage solidification and its content depends on the design of the gating system and the filling parameters [14][15][16]. Whilst porosity can be reduced to an acceptable level using high integrity processing techniques, it is impossible to eliminate it completely due to the limited feeding capacity of the melt resulting from high cooling rates and the compromise between productivity and product quality. ...
To reveal the influence of porosity on the variability in mechanical properties of HPDC Al alloys, micro computed tomography was employed to investigate the morphology and 3D distribution of porosity in the tensile samples. Experimental results show that the variability in mechanical properties of HPDC AlSi7MgMn alloy is related to the pore size and total volume of the porosity. The maximum pore size is inversely proportional to the elongation of the alloy with T6 heat treatment, while the total volume porosity was found to decline with increasing elongation. A maximum pore size of approx. 1.3 mm in diameter was found to correspond to an elongation of 6.4%. Once its maximum size reduced to less than 0.3 mm, the elongation was found to improve to 9%-13.5% for the alloy. Compared to the average value of 8.8%, 236.6 MPa, 296.0 MPa for elongation, yield strength and ultimate tensile strength respectively for the porosity-free AlSi7MgMn samples produced by gravity casting, the HPDC AlSi7MgMn alloy has the similar strength level and improved elongation to an average level of 11.5%. This indicates that the porosity level is a determined factor to the mechanical property variability and its size less than 0.3 mm has no significant adverse effect on the mechanical properties of the alloy. The elongation improvement in HPDC AlSi7MgMn alloy is attributed to the finer grain size with an average value of 10 μm compared to the average value of 500 μm for the gravity casting AlSi7MgMn alloy, and to the reduced size and uniform distribution of porosity resulting from the subsequent refinement in grain size.
... The gating system of a camshaft was studied by Jolly et al. 10 using numerical simulation techniques, and they showed that the porosity and the inclusion defects in the casting were caused by the excessive turbulence of the molten metal in the casting system. The pressure casting of thin-walled magnesium alloy parts was studied by Hu et al. 11 using casting numerical simulation technology, and the casting system was optimized and designed. Bansode et al. 12 used Taguchi's method to investigate the effect of critical process parameters of investment casting on dimensional variations of thin-walled, complex geometrical stainless steel component. ...
The water-meter shell has a complex-structured thin-walled cavity, and it can cause casting defects such as shrinkage and misrun. On the basis of structural analysis of a water-meter shell, a three-dimensional model and a finite element model of the water-meter shell were constructed using the SOLIDWORKS and ProCAST software as a modeling tool and a casting numerical simulation tool, respectively. Three processes associated with the bottom gating system without a riser, a step gating system with a preliminary riser, and a step gating system with an optimum riser were successively numerically simulated. The mold-filling sequence, temperature distribution, liquid-phase distribution during solidification, and shrinkage distribution of these three processes are discussed here. The numerical simulation results indicated that optimization of the casting process and the rational assembling of the riser led to the shrinkage volumes at the inlet position, regulating sleeve, and sealing ring of the water-meter shell decreasing from 0.68 to 0 cm ³ , 1.39 to 0.22 cm ³ , and 1.32 to 0.23 cm ³ , respectively. A comparison between model predictions and experimental measurements indicated that the castings produced by the optimized process had good surface quality and beautiful appearance, without casting defects, demonstrating that numerical simulation can be used as an effective tool for improving casting quality.
... Numerical simulation was carried out that showed the continuous gating system provided homogenous mould filling compared to the split gate system. A series of short shot experiments were carried out to validate the simulation results [4]. In die casting operation, porosity is a serious problem as it is invisible and cannot be identified visually. ...
... This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). turbulence resulting from formation of oxide film, dross, sand inclusion and air entrapment (Hu et al., 2000, Devendar et al., 2014. Precise gate sizes and shapes control the entering velocity of molten metal which results in air entrapment minimization (Runyoro, 1992, Wang et al., 2017. ...
This research aims to analyze the effects of bottom and top gating configurations on mechanical properties of aluminum alloy 6063-T5 in sand casting process. The influence of three most effective process parameters including pouring temperature, runner area and ingate area have been investigated. Empirical models for both bottom and top gating configurations have been developed using response surface methodology (RSM). Analysis of variance (ANOVA) and confirmatory experiments have been used to measure adequacy and validity of developed models respectively. Bottom gating was observed as better configuration as compared to top gating configuration with 4.08%∼18.78% higher ultimate tensile strength (UTS) and 5.98%∼20.60% higher percentage elongation. This resulted due to splashes generated by top gating configuration which severely affected the fluidity of the melt with consequent effects on mechanical properties. Pouring temperature and ingate area have been identified as the most significant process parameters affecting ultimate tensile strength and percentage elongation. Ingate area, on the other hand influences the flow pressure and speed of melt which is required for mold filling. Micro-hardness of the specimens has also been investigated to clarify the effects of gating configuration and input parameters on mechanical properties. To have a deeper insight of the findings, microstructural analysis of casted parts has also been carried out. The findings of this research will provide better insight of bottom and top gated sand casted parts and their effect on mechanical properties.
... High-pressure die casting is a popular manufacturing process to produce high strength and quality products in specified tolerances [1,2]. The basic steps of die casting are mold closing, mold filling, mold cooling, mold opening, and ejection [3]. ...
The work in this paper describes the design and simulation of highpressure die casting die (HPDC) for pinion housing for the automotive part. The material used for pinion housing is Aluminum alloy 6061. The casting simulations are based on ADSTFEAN casting simulation software. The work includes mathematical calculations for die performance parameters such as fill time, fill rate and design of the gating system, plunger velocity, and machine’s capacity. The study of fill time, product quality prediction, and optimum runner size is based on ADSTFEAN casting simulation system. Furthermore, simulations are carried out to decide the number of gate locations for better filling of the die.
... 2006. p. 56 [12], Wu et al. [13], Hu et al. [14]). Both gates are usually designed with converging cross-sectional area. ...
... Therefore adequate care is necessary in designing gating and risering systems for improved yield of defect free castings [8]. It has been shown that good gating system design could reduce the turbulence of melt flow, air entrapment, sand inclusion, oxide film and dross [9][10][11][12][13][14]. Melt flow influences solidification time, which is an important parameter that could alter the microstructure and mechanical properties of the cast part. ...
This research is about the Solidification and Casting related defects analysis which hampers the quality of a product. By using Casting Simulation software, It's been found that there is about 15% improvement of casting yield than the conventional gating and feeding system.
... Bottom filling approach was employed as shown in Fig. 4(b). It was concluded that runner with small height and large width is effective in reducing metal velocity at the ingate which is consistent as reported by Mi et al. (2009);and Hu et al. (2000). Kermanpur et al. (2008) simulated the filling and solidification sequence of brake disc and flywheel in multi-cavity molds. ...
The demands on the productivity and robustness of metal casting processes for high quality components are continuously increasing. Moreover, the financial considerations necessitate meticulous and reliable planning of the entire casting process before it is actually put into practice. A holistic approach to perform cradle to grave analysis of cast products is simulation-based metal casting. This method allows engineers to model, verify, and validate the process followed by its optimization and performance prediction in virtual reality. This paper provides insights on state of the art in simulation-based metal casting with reference to some case studies. Casting simulations software, mathematical models and solution methods, and casting process simulation together with the results obtained are clearly explained. The current practices revealed extensive utilization of simulation packages for defect minimization, yield maximization, and improved quality. The ongoing research on integration of casting simulations with mechanical performance simulations makes it possible to analyze the serviceability of cast parts. The reliability of cast part in service with dynamic loading of varying thermal and mechanical load cycles can be predicted through this integration. However, more rigorous work is needed in this area, particularly by developing the reliability prediction modules embedded in advanced simulation tools.
... Bottom filling approach was employed as shown in Fig. 4(b). It was concluded that runner with small height and large width is effective in reducing metal velocity at the ingate which is consistent as reported by Mi et al. (2009);and Hu et al. (2000). Kermanpur et al. (2008) simulated the filling and solidification sequence of brake disc and flywheel in multi-cavity molds. ...
The demands on the productivity and robustness of metal casting processes for high quality components are continuously increasing. Moreover, the financial considerations necessitate meticulous and reliable planning of the entire casting process before it is actually put into practice. A holistic approach to perform cradle to grave analysis of cast products is simulation-based metal casting. This method allows engineers to model, verify, and validate the process followed by its optimization and performance prediction in virtual reality. This paper provides insights on state of the art in simulation-based metal casting with reference to some case studies. Casting simulations software, mathematical models and solution methods, and casting process simulation together with the results obtained are clearly explained. The current practices revealed extensive utilization of simulation packages for defect minimization, yield maximization, and improved quality. The ongoing research on integration of casting simulations with mechanical performance simulations makes it possible to analyze the serviceability of cast parts. The reliability of cast part in service with dynamic loading of varying thermal and mechanical load cycles can be predicted through this integration. However, more rigorous work is needed in this area, particularly by developing the reliability prediction modules embedded in advanced simulation tools.
This study contributed to the comparison of insulation cotton configurations for the investment casting quality of industrial valve parts. Due to the complexity, parts of industrial valve bodies are usually produced by casting. However, the investment casting production process has several problems, such as shrinkage porosity. Currently, the investment casting industry uses cotton configuration to solve the problem of shrinkage porosity. Therefore, this study compared three cotton installation treatments in the mould shell to determine the optimal use of cotton. There are three schemes of the type of cotton installation on the shell that will be observed, including the triangular insulation cotton area denoted as Case A installed 55mm and Case B installed 90mm cotton on the right and left sides, and Case C denoted with adding bracket arms on the upper side. In this study, we used RMM (Retained Melt Modulus) and the finite element model to analyze the shrinkage porosity's location and to monitor the porosity that occurred during the solidification process. The result showed that cotton could reduce shrinkage porosity by 3.30%, 1.95%, and 1.47% for Case A, Case B, and Case C, respectively. Therefore, the best alternative is to add the cotton and bracket arm on the upper side, which is the optimal strategy to prevent shrinkage porosity.
The weight and speed advantage of aluminum die-casting leads to its use in many parts in the automotive industry. Casting simulation programs are used, to avoid time-consuming and expensive production costs, and to design the production process. For casting production one of the most important factors is the runner design, which directly affects castability, material selection, and casting quality. With the correct design of runner systems, there will be no problem with the casting part. In this study, the final part and the runner design for the aluminum alloy valve cover were modeled in CAD, according to the empirical calculations. Furthermore, an appropriate casting method was selected for the valve cover not only according to the results of both high-pressure die-casting and sand-casting simulations but also economic calculations. The main technical parameters for selection were mold and part temperature distribution, liquid metal flow rates, cold shut possibilities, final air quantities, microporosity, and microporosity values. After the final decision, the casting part was produced with high pressure die casting by the implementation of the final runner design.
The impacts of gating design and riser system on structure-property relationship of high manganese steel specimens produced by CO2 sand molding process were systematically examined. The designing of gating and riser system was done first using the traditional manual method and then by SolidCast simulation method. Confirmatory experiments were done to validate the obtained results. Castings were produced using both designs to verify the extent of defects. Their microstructural and mechanical properties were explored. Visual examination of castings designed by manual method showed major shrinkage defects, whereas software designed castings were quite sound showing no shrinkage (macro porosity) and micro porosity. Furthermore, optical microscopy and SEM analysis were performed to study microstructure of the specimens. It was found that the defect-free, software-designed castings with optimized parameters showed ∼25 % improvement in yield strength, ∼20 % in tensile strength and ∼30 % in hardness.
The present work aims to investigate the different casting defects that arose during the gravity die casting process of an IC engine block made of AA 7075 alloy and also highlights the feasible solutions to eradicate those defects. The minimization of the casting defects is a very crucial task in an IC engine block. Experimental studies which are generally performed to reduce the casting defects are proven to be strenuous, costly, and time-consuming. To counter this, a thermal simulation model is proposed in the present study to identify the effect of the pouring temperature, mould temperature, and the number of chillers on the various casting defects such as cold shuts, air entrapment, mould erosion, and microporosity. A detailed parametric study is conducted on the proposed model to evaluate the outcomes of important process variables on the resulting casting defects. The simulation results predict, at pouring temperature of 963 K, mould temperature of 293.15 K and with the use of 2 chillers defect-free IC engine blocks can be casted. The optimum result obtained by the proposed model is validated by conducting a confirmative test predicting an average error of 6.98%. The proposed model is effective enough in getting rid of the numerous casting defects which cannot be identified using the traditional methods; thus increasing productivity. This can be used as an economical time-saving substitute to the experimental methods during casting of various engine parts.
Casting is the oldest manufacturing method and well-known metallurgical process. Casting process basically
involves introduction of molten metal into a mold cavity and subsequently the molten metal takes the shape of mold
cavity. This paper presents an intelligent design environment to assist product engineers in assessing a part design for
castability. The software simulates the way casting engineers decide the casting process, parting line, cores, mold box,
feeders, gating system and mold layout, and analyzes each decision to suggest how the design could be modified to
improve quality as well as reduce tooling and manufacturing costs. Usually there is more than one cause for the
generation of nonmetallic subsequent to ladle metallurgy, and this paper briefly reviews several of the factors in liquid
handling that remain as contaminating mechanisms It is argued that the clogging of the tundish-to-mold pouring system is
due to nonmetallic formed primarily by reoxidation.
Casting industries play a crucial role in various industrial sectors like Defence, Automotive sectors, Construction, Agriculture, Aerospace, Oil & Gas (energy sector), Mining, Railroad, Water infrastructure, Transportation, and Health & Medical care. The review article integrates various algorithms, methods, and processes to design an industrially accepted, scientifically sound, reliable feeding system. This systematic review brings out the use of different software used in industry to create and analyze the overall casting process like PRO-cast, MAGMASOFT, ANSYS, CAD software, etc. It also highlights various gating systems for many vital metals and alloys like AZ91, Al-12Si, steel, etc. Moreover, it gives an insight into the casting technology for manufacturing profound components of industrial locomotives and machines like turbine housing, large full-spade carrier housing with axisymmetric large offshore structures with the optimization of the gating system. It concludes that designing a sound feeding system is possible by adequate mathematical tools and numerical simulations.
In this study, HPDC is introduced into the production of oil circuit board, aiming to solve forming defects and provide a complete design concept for the exploitation of die-casting process in large castings. First, the die-casting die was designed and its rationality was verified, but the unreasonable selection of injection process parameters caused casting non-conformance. Next, the experimental data of L25 orthogonal array of Taguchi method were used as training samples and the porosity of the die-cast part was examined in relation to casting variable parameters. Specifically, the velocity, temperature and injection pressure were mainly investigated, while the mathematical model passed the test of accuracy. Finally, Particle Swarm Optimisation (PSO) algorithm was used to optimise the model, achieving minimum porosity. The results have shown that the PSO algorithm optimisation results are better than the one produced by the Taguchi method, providing a significant improvement over the pre-optimisation results.
In the advancement of smart production across all types of casting processes, this paper analyzes the importance of process parameters and the latest developments in modern tool development. Different influencing variables such as size, location and number of gates on feeding mechanisms were addressed in relation to casting defects. The study shows a decrease in the defects of the casting parts by selecting an optimized feed template such as air bubbles, blow cracks, shrinkage defects and mechanical properties. Factors affecting the hot spot location were found to be variations in the radius of fillets and the thickness of feeding devices. The mobility of the hot spot was therefore regulated by geometrical modifications in the feeding system. Additionally, by proper feeding system arrangement, the development of pinholes and solidification flaws could be minimized. The rapid growth in the use of simulation technology in the casting process would help to increase yields by reducing the cost of production. This article provides their industrial applications with a database relating to the merits and demerits of different factors and material systems in order to allow for more casting process research.
The failure of dies and its repairing options are very important in die casting industries. Of all the casting processes available, pressure die casting finds wide applications in large scale production of complex shaped objects with intricate geometries that require good surface finish and dimensional stability. The cooling system employed in the die not only facilitates proper solidification of the cast components but also helps in maintaining the die temperature and controlling the stresses generated during the cyclic operation. The research work focuses on designing a die of H13 material for ADC12 cast part that is to be operated on 160 Tonne Cold Chamber HPDC machine. The effect of cooling system location on the stresses produced in die is analysed and their optimum location is determined by ANSYS. Further, filling simulation of the modified design was carried out and minor modifications are made to optimize the filling operation using MAGMA Software. The research work proves to be useful in increasing the die life by considering the optimization of cooling channel position along with the gating system design in the design stage.
A most important progress in civilization was the introduction of mass production. HPDC molds are one of main technologies for mass production. Due to the high velocity of the liquid metal, aluminum die-casting is so complex where flow momentum is critical matter in the mold filling process. Actually in complex parts, it is almost impossible to calculate the exact mold filling performance with using experimental knowledge. Due to this condition in the design procedure, the simulation is becoming more important. Simulation can make a casting system optimal and also elevate the casting quality with less experiment. The most advantage of using simulation programs is the time and cost saving of the casting layout design. The condition selection of HPDC mainly relied on the experience and expertise of an individual worker in casting industries. Systematic knowledge accumulation of die casting process was an essential matter to get optimal process conditions.
In present casting industries, product development paradigm is shifting from traditional trial-and-error to proof-of-concept based on CAE -enabled simulation. Due to the high velocity of the dynamic behavior of the casting system in working conditions, aluminum die casting is a very complex process in which flow momentum is a critical issue in the mold filling process. In the new production development paradigm, CAE simulation plays an important role because it models the entire casting process and reveals the dynamic behavior of the casting system. In this research, CAE simulation was performed by using the simulation software (AnyCasting) in order to optimize the gate and runner design of an automobile part (Oil Pan_BR2E) which is well known and complicated to achieve a good casting layout. Filling analysis was used to find out the size and location of the gate and proper runner system design. By the modification of the gate and runner system and the configuration of overflows, internal porosities caused by air entrapments were predicted and reduced remarkably. With the solidification analysis, internal porosities caused by the solidification shrinkage were also predicted.
This paper relates with casting defects like shrinkage, scabs and runner & riser defects which mainly occurs in manifold casting in foundry. The research on controlling the casting defects in foundry shop which comes in manifold 380 and these causes may result the reduction of quality of casting. Efforts has been made to minimize the casting defects using L 9 Taguchi's orthogonal array approach through change in various parameters like as compression strength, moisture, permeability number and mould hardness number. These experiments are conducted on the basis of standard acceptance and experience of foundry men of casting setup for casting of manifold 380 taken during controlling the parameters. Range of these parameters has been defined for casting process at different trials. L 9 Taguchi's orthogonal array method in MINITAB 17 software has been used to find out the best optimum solution. These optimum solutions are applied on casting process and percentage rejection was found to be 0.96%. Also, by modulus calculations it has been made able to redesign the gate for controlling metal fluidity, turbulences in molten stage of metal which can withstand the sand permeability and strength to eliminate the scabbing defects in castings and to analyze simulation results.
Continuously cast large round blooms have gained widespread attention owing to the improved quality, enhanced economy, higher yields, and lower operating costs obtained through continuous operation. Because the continuous casting process combines the cleanliness and radial solidification symmetry of the ingot casting process with the higher axial symmetry obtainable through bloom casting, it can deliver a more homogeneous product than conventional ingot casting. This paper discusses the shop floor manufacturing of a main shaft to confirm the feasibility of using continuously cast round bloom in the manufacture of heavy forgings. For comparison, the characteristics of a 1,000‐mm‐diameter continuously cast round bloom were assessed against those of a conventionally cast 20.6 ton ingot. To eliminate cavities at the centerline of the cylindrical bloom, additional studies on void closure efficiency at the center of the billet under various forging die geometries (e.g., flat‐, V‐, and round‐die) were performed, and the results reveal that the V‐die geometry is most effective in consolidating centerline voids. A comparison of the respective operational characteristics revealed that the round bloom continuous casting method could be feasibly applied in the manufacture of main shafts.
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It is essential to develop an innovative type of material for improving the mechanical and tribological properties from the existing one in the field of materials. New developments are focussed not only to improve the above said properties of materials, also to have contradictory combinations of properties. Functionally graded material (FGM) is one that will be providing solution to upcoming applications. In this paper, fabrication of FGM using centrifugal casting method is discussed. This method is widely used, because of its commercial viability and less technology requirements, compared to other methods of fabrication. A centrifugal casting setup is fabricated to develop FGM parts. Technical considerations in designing of centrifugal casting setup highlights the problems encountered and considerations while fabricating it. Influence of parameters like processing temperature, cooling rate, particle size, density and rotational speed of mould, on fabrication of centrifugally cast part are discussed, to understand their effect in modifying the properties of materials. With improved properties and their combinations, FGMs satisfy the needs across various applications such as biomaterials, aerospace, thermal barrier coatings, which are growing further and few applications where it is being used are deliberated.
Designing in die casting is a critical activity for
die manufacturing. Further, activities like cavity design,
cavity layout and design of gating system are essential in
design of a die casting die. Design of gating system for a
die casting die is dependent upon a various parameters
which are influenced by part design, die casting machine
and die casting alloy. Gating system design requires lot of
manual input and a number of iterations to finalize the
design. This requires a good knowledge of die casting
process, making this activity completely dependent on the
user. In present day industry, lot of CAD/CAM tools are
applied for design, development and manufacturing of a
die casting die. However, need of die casting expert
throughout design and manufacturing of die-casting die
makes it a quite lengthy process. Gating system design
being one of the major activities in die design also takes
much time. Therefore, it would be quite beneficial to
develop a system for automated generation of gating
system. The system would go a long way in bridging the
gap between designing and manufacturing of die-casting.
Low power Yb-fibre laser surface melting (LSM) was applied to modify the AZ31B magnesium alloy. The LSM treated samples presented poor formation qualities when the laser power was lower than 80 W. Samples without obvious macro-defects were obtained as the laser power higher than 88 W. The thickness of each melted layer was less than 125 μm. The grains of melted layer were refined and the solid solubility of aluminum increased. The average microhardness of the LSM treated samples was improved 37.7%. The corrosion resistance of LSM treated samples was raised by an order for magnitude and the wear resistance was improved 33% when the laser power was 104 W.
In the 1980s, John Campbell developed a new casting
process from his research in the industry over a number of years. The Cosworth
process was for delivering very high-quality aluminium components for the automotive industry. The process was very capital-intensive and not very flexible for smaller companies delivering lower volumes of product. However, the principles behind the process have been taken and used to develop a range of different so-called running systems to help improve the quality of castings. Some of these designs have been published in ‘Castings Handbook’ [1] authored by Campbell. This paper presents the results of an MSc project during which a number of the proposed designs from Campbell’s Mini Casting
Handbook [2] for certain features in running systems have been modelled using a validated CFD software.KeywordsGravity sand castingRunning system designNumerical simulationVortex gateTrident gateBubble trapMultiple-in-gateAir entrainmentGate velocity
In high-pressure die casting component, shrinkage defects plays a major role in leakage of fluid from components; therefore, it becomes necessary to predict the exact location of the shrinkage defect to reduce its intensity to an acceptable level. Nowadays, a localized squeezing process is one of the popular ways of reducing the shrinkage defect in high-pressure die casting components. Squeeze pins can be used to compensate for shrinkage defects in these components. The main reason for the formation of shrinkage porosity at the critical location of a given component is large and poorly fed hot spot. In this paper, shrinkage defects are reduced from level III to level I by determining optimum values of squeeze pin parameters by DOE and flow simulation, obtained results are implemented in order to test and verify effectiveness of the method. An excellent agreement is indicated for the simulation result and the experimental results.
Die Casting Dies: Design, North American Die Casting Association
- E A Herman
E.A. Herman, Die Casting Dies: Design, North American Die Casting Association, 1992, pp. 15±24.
Process diagnosis and optimisation in pressure die casting
- B H Hu
- K K S Tong
- F C Yee
- D Sudheeran
- K T Tan
B.H. Hu, K.K.S. Tong, F.C. Yee, D. Sudheeran, K.T. Tan, Process diagnosis and optimisation in pressure die casting, Proceedings of the Third International Conference on Die and Mould Technology, Taipei, Taiwan, Vol. A, 1995, pp. 137±142.
Industrial application of computer simulation in mould design for pressure die casting
- K K S Tong
- B H Hu
- F C Yee
K.K.S. Tong, B.H. Hu, F.C. Yee, Industrial application of computer simulation in mould design for pressure die casting, Proceedings of International Conference on Mechanics of Solids and Materials Engineering, Singapore, Vol. A, 1995, pp. 235±240.
Optimisation of mould design in die casting of Pewter parts through numerical simulation
- B H Hu
- S W Hao
- X P Niu
- K K S Tong
- F C Yee
B.H. Hu, S.W. Hao, X.P. Niu, K.K.S. Tong, F.C. Yee, Optimisation of mould design in die casting of Pewter parts through numerical simulation, Proceedings of the Fourth International Conference on Computer Integrated Manufacturing, Singapore, Vol. 2, 1997, pp. 885±893.
Modelling of diecasting processes using magmasoft, Transactions of the 17th International Die Casting Congress and Exposition
- M A Osborne
- C E Mobley
- R A Miller
- L H Kallien
M. A. Osborne, C. E. Mobley, R. A. Miller, L. H. Kallien, Modelling of diecasting processes using magmasoft, Transactions of the 17th International Die Casting Congress and Exposition, Ohio, USA, 1993, pp. 77±84.
Numerical modeling of filling and solidification in die casting, Transactions of the 17th International Die Casting Congress and Exposition
- D Frayce
- J F Hetu
- C A Loong
D. Frayce, J. F. Hetu, C.A. Loong, Numerical modeling of ®lling and solidi®cation in die casting, Transactions of the 17th Interna-tional Die Casting Congress and Exposition, Ohio, USA, 1993, pp. 13±17.
Numerical simulation of die cavity filling in die castings and an evaluation of process parameters on die wear, Transactions of the 17th International Die Casting Congress and Exposition
- K Venkatesan
- R Shivpuri
K. Venkatesan, R. Shivpuri, Numerical simulation of die cavity ®lling in die castings and an evaluation of process parameters on die wear, Transactions of the 17th International Die Casting Congress and Exposition, Ohio, USA, 1993, pp. 1±11.
Flow analysis in tapered runners, Proceedings of the 10th SDCE International Die Casting Exposition and Congress
- T H Siauw
- A J Davis
T.H. Siauw, A.J. Davis, Flow analysis in tapered runners, Proceed-ings of the 10th SDCE International Die Casting Exposition and Congress, Missouri, USA, 1979, pp. 1±9.
Castability study for die casting of a thin-walled magnesium part
- B H Hu
B.H. Hu, et al., Castability study for die casting of a thin-walled magnesium part, in press.
Application of numerical simulation in die casting processes, mould design in
- X P Niu
- S W Hao
- B H Hu
- K K S Tong
- F C Yee
Optimisation of die cast parts using numerical simulation of die filling and solidification, Transactions of the 17th International Die Casting Congress and Exposition
- L H Kallien
- M Lipinski
Understanding the filling patterns in magnesium die casting using particle-tracing technique during numerical simulation
- B H Hu