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Environmental Aspects of Abrasive Water Jet Cutting
Abstract
Traditional method of production has a negative impact on the environment by cutting and erosion products (chips and microchips), the used coolant (oils and emulsions, enriched aggressive chemicals) and high energy consumption. Modern systems for mechanical processing should be minimal this impact. This paper presented a study of advanced machining – Abrasive Water Jet (AWJ) technology in environmental aspects. Unlike traditional machining (grinding, milling) water jet cutting does not emit into the environment any dust or particles that are harmful if inhaled. Also presents an analysis of the fragmentation garnet – commonly used abrasive in this technology, ilmenite and olivine, and identified recycling potential of these abrasives.
... Among the abrasives, especially alluvial garnet, the recovered abrasive turns out to be more effective as the cutting edges are sharper (Fig. 2). Additionally, recycling of the abrasive materials can performs the abrasive water jet technique more saving, effective, and environmentally friendly [12]. For these reasons, research on the recycling of abrasives, especially garnet, is the subject of research in various scientific centers. ...
... For all tested abrasive size range is within the range of 350 to 125 m. To establish what fraction of the original range is found in the jet formed in the cutting head, all of the fractions smaller than the lower limit of the particle distribution, were rejected as ineffective in the cutting process [12]. It is illustrated in Fig. 7. Details of abrasive material distribution presents Table 8. ...
... It is illustrated in Fig. 7. Details of abrasive material distribution presents Table 8. In the recycling process of alluvial garnet, grains smaller than the limit (for grains # 80 it is 90 m) was removed as inefficient during the cutting process [Perec, 2018]. The very small positive asymmetry density function approximating the grain distribution can be visible. ...
The size and distribution of abrasive particles have a significant influence on the effectiveness of the cutting process by the high-speed abrasive water jet (AWJ). The paper deal with the abrasive materials disintegration intensity in AWJ cutting during the creation of the abrasive jet. An evaluation of the abrasive materials grabbed after forming in the cutting head was carried out and its grain distribution was evaluated. Used here the arithmetic, geometric and logarithmic method of moments and Folk and Ward method. The influence of abrasive concentration of abrasive materials as alluvial garnet, recycled garnet, corundum, and olivine on grain distribution was studied. A recovery analysis was also carried out and the recycling coefficient for each tested abrasive material was determined.
... High-speed water jet machining is a fast-growing advanced manufacturing technology. The features of this technology are particularly environment friendly [1,2]. Additionally, it successfully competes with traditional materials cutting methods. ...
... The underside PVC collector was shielded by a mild steel target to avert perforation. No wear marks were noticed on the safeguarding target after the termination of tests [2]. The caught abrasive grains are then dried. ...
The article presents research on the erosion of the metamorphic rock-marble by the Abrasive Water Jet (AWJ). The fragmentation of abrasive grains during the erosion process is demonstrated. The effect of the cutting process's most important parameters as traverse speed, nozzle ID, and abrasive mass flow rate, on the maximum cutting depth, is shown. To create a mathematical-statistic model of the erosion process, the methodology of the response surface (RSM) was used for modeling. The polynomial equation of the second degree is chosen for developing the regression model. Studies have shown the optimal parameters of the process, to reach the highest depth of the cut. Additionally, the erosion wear of a focusing tube under different process conditions is presented.
... Among the methods of machining special attention they deserve environmentally friendly. This is mainly plastic processing [8,9] and high pressure water jet technology [15]. ...
... The cost of abrasive is the main cost of processing an abrasive water jet [15] therefore purposeful work aimed towards the use of the cheapest abrasive materials and their recycling. ...
Este trabajo presentó un estudio de la desintegración abrasiva en un chorro de agua abrasivo de 400 MPa (AWJ). El tamaño y la distribución de partículas abrasivas juegan un papel importante en el mecanizado y la eficacia de corte de los chorros de agua abrasiva. Abrasivo de granate probado, comúnmente utilizado en el tratamiento con chorro de agua abrasivo y corindón. Es de interés científico observar la desintegración de estas partículas que han sido interactivas con materiales abrasivos poco comunes. El impacto del tiempo de los granos abrasivos en la pieza de trabajo es muy corto y no todo el grano en la corriente de poder hacer el trabajo de corte, debe esperar la posibilidad de recuperar el tratamiento abrasivo. Considerable importancia es el aumento en la capacidad de corte de granos triturados debido a revelar nuevos bordes de corte. Con base en un estudio de factibilidad, este documento presentará algunos resultados sobre los datos de corte obtenidos y muestra también el desgaste del tubo de enfoque utilizado, la principal parte responsable de la formación del chorro.
... The higher pressure generates bigger abrasive grains velocity in the AWSJ nozzle, and the processed material and the disintegration process takes place more intensively. This observation is in line with the research on the disintegration of the abrasive in the AWIJ cutting process [42,44]. ...
The paper introduces the study on the cutting of the industrial composite phenolic resin, based on the thermoset materials reinforced with cotton cloth by the Abrasive Water Suspension Jet (AWSJ). The size reduction of abrasive grains during the formation of the jet and the erosion phenomenon are shown. The results of the machining process's critical factors as nozzle length, nozzle diameter, and abrasive mass flow rate on the maximal cutting depth, are indicated. To build a model of the process, the method of the response surface (RSM) was applied. The second-degree multinomial equation is selected for creating the cutting model. The research indicates the optimal control factors of the process, to achieve the best cutting depth performance.
... The higher pressure generates bigger abrasive grains velocity in the AWSJ nozzle, and the processed material and the disintegration process takes place more intensively. This observation is in line with the research on the disintegration of the abrasive in the AWIJ cutting process [42,44]. ...
The paper introduces the study on the cutting of the industrial composite phenolic resin, based on the thermoset materials reinforced with cotton cloth by the Abrasive Water Suspension Jet (AWSJ). The size reduction of abrasive grains during the formation of the jet and the erosion phenomenon are shown. The results of the machining process's critical factors as nozzle length, nozzle diameter, and abrasive mass flow rate on the maximal cutting depth, are indicated. To build a model of the process, the method of the response surface (RSM) was applied. The second-degree multinomial equation is selected for creating the cutting model. The research indicates the optimal control factors of the process, to achieve the best cutting depth performance.
... In addition, abrasive waterjet cutting has demonstrated the ability to achieve high precision machining of light alloys while offering benefits such as high material removal rates, low cutting stresses and low temperatures. Compared to conventional machining technologies, abrasive waterjet cutting also offers superior environmental performance [10][11][12][13]. This makes this technology a very interesting alternative. ...
Abrasive waterjet cutting is a valuable method for removing material without causing thermal damage, making it suitable for machining materials of different thicknesses and minimising waste. However, machining thicker materials requires higher flow rates and pressure, resulting in increased energy consumption and surface defects that increase costs. This study proposes a multi-pass strategy to improve the performance of abrasive waterjet machining. The study aims to investigate the impact of the number of passes on the efficiency of machining a thick UNS A92024 alloy. Surface integrity will be evaluated from two perspectives: macrogeometry (such as machining depth and taper) using image processing, and microgeometry (surface roughness). The study will also analyse the relationship between the number of passes and traverse speed to identify the optimal combination and develop a predictive model to enhance overall process performance.
... Perec [5] studied the recycling capabilities of garnet and corundum based on the aspect of abrasive disintegration and showed that although corundum can have larger recyclability in some cases, it is related to excessive focusing tube wear. The same researcher also conducted other relevant studies [6,7] in which it was found that garnet has greater recyclability potential than olivine and ilmenite and that the use of recycled abrasives such as crushed glass has considerable potential for cutting. Kantha Babu and Krishnaiah Chetty [8] revealed that the disintegration degree is larger for fresh abrasives than recycled ones, due to their larger dimensions, leading to easier fragmentation. ...
Abrasive waterjet technology is nowadays a well established non-conventional method with significant capabilities for material removal with high productivity and minimum environmental impact compared to other processes. However, in order to be in line with the green transition directives, further steps are required to ensure the sustainability of manufacturing processes and reduce the risk of material depletion by employing recyclable materials. For this purpose, an eco-friendly abrasive material such as walnut shell is employed for pocket machining of a titanium alloy workpiece. Due to the relatively low hardness of this material, compared to common abrasive materials such as garnet or alumina, it is required to determine the appropriate range of process parameters in order to obtain high-quality pockets with high productivity. Thus, in this work, a comprehensive experimental study is conducted in order to determine the effect of various process parameters on pocket depth, pocket width, material removal rate, flatness and parallelism error of produced pockets. The results prove the feasibility of using walnut shell as abrasive material for pocket milling, although MRR is almost an order of magnitude lower than the values commonly obtained for usual abrasives. Moreover, it is not recommended to use jet pressure values over 250 MPa so dimensional accuracy, flatness and parallelism error are maintained in acceptable values.
... A further advantage of AWJ technology is its environmental friendliness, since amid the known treatment method of machining only plastic processing [11,12] and AWJ cutting [13,14] can stand up to these requirements. ...
Composites are materials with a heterogeneous structure, composed of two or more components with different properties. The properties of composites are never the sum or average of the properties of their components. There is a lot of research and many models on the different property assessments of composite materials. Composites are used as construction materials in key areas of technology, including in civil and mechanical engineering, aviation and space technology, and others. This work presents a modern composite material created with 3D-printing technology using the SLM method, and the possibility of its processing with one of the advanced manufacturing technologies, i.e., the Abrasive Water Jet (AWJ). Tests planned using DoE methods were carried out by changing control parameters such as the pressure, abrasive flow, and traverse speed. As a dependent parameter, the surface roughness parameter Sq (squared mean height) was selected and measured in different places of the cut composite. Based on the S/N ratio, the most favorable control parameters of the cutting process were also determined to achieve the lowest roughness of the cut surface. A clear effect of the controlled cutting process on the surface roughness was observed, as well as roughness variation for the metal and polymer component. In addition, the contact surface of the polymer with the metal in the cut zone was analyzed. Analysis of the contact surfaces on the microscope showed that the gap between the polymer–metal contact surfaces does not exceed 2.5 μm.
... At present, water jet cutting technology has been widely applied in industry, medicine, and other fields, involving ores, metals, plastics, and other materials, accompanied by a variety of technical and theoretical supports [6][7][8][9][10][11][12][13][14][15]. There are many specific advantages that have been found. ...
Cutting is a significant part of agricultural material processing, and the cutting technology determines the quality of agricultural products. Water jet cutting technology is a non-contact and cold cutting technology suitable for cutting agricultural materials. It can realize an environmentally friendly cutting process avoiding such problems as heat generation, sharpening and cleaning blades, and microbial cross-contamination. This paper reviews the current status of water jet cutting of six kinds of agricultural materials, including vegetables, fruits, meats, woods, stems, and soils. By analyzing how to complete different cutting operations, improve cutting ability, or control post-cutting influences, the problems and solutions of water jet cutting of each material are summarized. Then, combined with the application requirements, some suggestions are put forward for developing water jet cutting technology. The results would help researchers determine key information required by cutting agricultural materials and provide a reference for further research on water jet cutting technology in agricultural engineering.
... In the literature, the most commonly reported results are the use of high-pressure waterjet for cutting [22,23] rather than cleaning, where the abrasive is usually garnet, corundum, or olivine. There are also published papers addressing the disintegration intensity of abrasives in the high-speed abrasive water jet (AWJ) cutting process [24][25][26][27][28]. New research has also been devoted to optimizing the cutting parameters of SiC-reinforced aluminum composite [29], and titanium alloy [30]. ...
The paper presents the results of investigations into the possibility of using ahigh-pressure water-ice jet as a new method for removing a worn-out paint coating from the surface of metal parts (including those found in means of transportation) and for preparing the base surface for the application of renovation paint coating. Experimental investigations were carried out in four stages, on flat specimens, sized S × H = 75 × 115 mm, cut from sheet metal made of various materials such as steel X5CrNi18-10, PA2 aluminium alloy and PMMA polymethyl methacrylate (plastic). In the first stage, the surfaces of the samples were subjected to observation of surface morphology under a scanning electron microscope, and surface topography (ST) measurements were made on a profilographometer. Two ST parameters were analysed in detail: the maximum height of surface roughness Sz and the arithmetic mean surface roughness Sa. Next, paint coatings were applied to the specimens as a base. In the third stage, the paint coating applied was removed by means of a high-pressure water-ice jet (HPWIJ) by changing the values of the technological parameters, i.e., water jet pressure pw, dry ice mass flow rate m˙L, distance between the sprinkler head outlet and the surface being treated (the so-called working jet length) l2 and spray angle κ for the following constants: the number of TS = 4 holes, water hole diameter φ = 1.2 mm and sprinkler head length Lk = 200 mm. Afterwards, the surface morphology was observed again and the surface topography of the specimen was investigated by measuring selected 3D parameters of the ST structure, Sz and Sa. The results of investigations into the influence of selected HPWIJ treatment parameters on the surface QF removal efficiency obtained are also presented. Univariate regression functions were developed for the mean stripping efficiency based on the following: dry ice mass flow rate m˙L, working jet length l2 and spray angle κ. Based on these functions, the values of optimal parameters were determined that allow the maximum efficiency of the process to be obtained. A 95% confidence region for the regression function was also developed. The results demonstrated that HPWIJ treatment does not interfere with the geometric structure of the base material, and they confirmed the possibility of using this treatment as an efficient method of removing a worn paint layer from bases made of various metal and plastic materials, and preparing it for applying a new layer during renovation.
... Abrasive water jet [1], [2], [3] and pulsating water jet [4], [5] treatment are devoid of such disadvantages. An additional advantage of the water jet technology is its environmental friendliness [6], [7]. The abrasive water jet processing in the last few years effectively competes with conventional methods for separating materials. ...
The paper presents the results of the optimization of high-speed Abrasive Water Jet (AWJ) machining. The complexity of the problem, conditioned by mutually opposite parameters: maximal cutting depth and minimal surface roughness is the reason for using the Response Surface Method (RSM) optimization methods. The three most influencing parameters were subjected to the process: process pressure, abrasive flow rate, and traverse speed. Based on RSM and analysis of variance, the machining model in the form of a full quadratic equation was formulated. To estimate multicollinearity, the variance inflation factor (VIF) was examined. A set of optimal control parameters was determined based on the composite desirability function. The description of the conducted research and the results of the verification were proving the high accordance of models with experimental data.
... In addition, this technology offers advantages such as the recovery of abrasive particles after machining, which can be reused after treatment, and no harmful gases are generated [25]. Another advantage is the reduction of cutting forces and temperatures, minimizing thermal defects in both materials -especially in CFRTPs-achieving a cleaner and more homogeneous cut [26,27]. ...
The bonding of Carbon Fibre Reinforced ThermoPlastic composites (CFRTP) and steel is of great interest nowadays. Nevertheless, the difference in machinability between dissimilar materials requires a specific machining process. Abrasive water jet machining is a flexible and environmentally friendly technology that can machine dissimilar materials at the same time with good results. However, due to the characteristics of the process and materials, geometrical defects such as taper angle can be caused by the loss of kinetic energy.
In this research, the study of the final geometry in abrasive waterjet machining of a hybrid CFRTP/Steel structure. A new methodology for the evaluation of taper angle with high accuracy has been developed through image processing. In addition, the surface quality in terms of Ra and Rz has been assessed. A potential-type trend between taper and hydraulic pressure has been established for both materials. Minimum taper values between 1.5° and 5° have been obtained for both materials and stacking configurations with a combination of a hydraulic pressure of 420 MPa, an abrasive mass flow of 225 g/min and a traverse speed of 50 mm/min.
... Among the abrasives, especially alluvial garnet, the recovered abrasive turns out to be more effective as the cutting edges are sharper ( Figure 2). Additionally, recycling of the abrasive materials can mean the abrasive water jet technique results in more savings, is effective, and environmentally friendly [13]. For these reasons, research on the recycling of abrasives, especially garnet, is the subject of research in various scientific centers. ...
The size and distribution of abrasive particles have a significant influence on the effectiveness of the cutting process by the high-speed abrasive water jet (AWJ). This paper deals with the disintegration intensity of abrasive materials in AWJ cutting during the creation of the abrasive jet. An evaluation of the abrasive materials was performed after forming in the cutting head was carried out and grain distribution was evaluated using the geometric and logarithmic Folk and Ward method. The influence of the abrasive concentration of abrasive materials such as alluvial garnet, recycled garnet, corundum, and olivine on grain distribution was studied. A recovery analysis was also carried out and the recycling coefficient was determined for each abrasive material tested.
... After analyzing the influence of traverse speed, particle size, abrasive flow rate, and abrasive particle size distribution on abrasive disintegration process, Guo et al. [8] found that the particles in the range of 90-500 μm disintegrate in the same way and the number of reuses exerts no impacts on the cutting efficiency of abrasive. As abrasive, garnet had more recycling potential than olivine and iimenite [9]. Perec [10] observed the decrease of the difference in particle size distribution after acceleration through the orifice and the focusing tube, and abrasive concentration and orifice to focusing tube ratio played an unimportant role in the degree of fracturing of the abrasive. ...
As the only cold high-energy beam machining technology, abrasive water jet cutting has a lot of unique advantages to process a large variety of materials. The main factor restricting its development and application refers to its high processing cost. Abrasive consumption is considered as one of the main costs. Abrasive recycling is an effective way for reducing the cost. In addition, it is also beneficial to environmental protection. Abrasive suspension water jet (ASJ) is more suitable for abrasive recycling than traditional abrasive water jet (AWJ) because ASJ does not use dry abrasives. Based on the idea of strive for the recycling process simple and effective, the abrasive recycling of ASJ was studied in this work. It is found that the recycled abrasives with only big particle impurity being sieved out still have strong cutting ability. An simplified abrasive recovery scheme of ASJ cutting system has been proved to be feasible. With 30% of recharge in each cycle, the abrasive can be fully utilized and its cutting performance can remain basically the same in every reuse cycle of continuously recycling process. The abrasives between 90 and 180 μm are optimal abrasives for the cutting surface roughness, compared with the larger size abrasives; the smaller size abrasives have more negative influence on the surface roughness, which should be concerned in the recycling process.
... Abrasive water jet [1,2] and pulsating water jet [3,4] treatment are devoid of such disadvantages. An additional advantage of the water jet technology is its environmental friendliness [5,6]. ...
The paper shows multiple performance optimisation of Hardox steel machining effects by the Abrasive Water Jet (AWJ). An innovative Entropy/VIKOR approach is implemented for the optimisation of parameters in cutting like pressure, feed rate, and abrasive flow rate over cutting depth, cut surface roughness, and angle of cut kerf was conducted. For determine the best set of the process control parameters VIKOR approach with entropy-based weights determining was done. To establish the weights of the initial parameters, it was proposed to calculate individual weights based on entropy. For the multiple criteria optimisation VIKOR approach was assumed.
... The experiments were conducted using a full factorial design model in view of three of the control parameters: pressure, traverse speed, and abrasive flow rate ( Table 2). Parameters were chosen on the basis of earlier obtained research results [15], [18] and publications of other researchers [2], [5], [6], [22]. Surface roughness measurements were carried out in the middle of the cutting zone in a 1.5 mm x 1.5 mm elemental area by using a Sensofar -Model S neox -Five Axis 3D Optical Microscope. ...
This paper presents the results of the Abrasive Water Jet (AWJ) cutting process optimization for Hardox® steel. This type of steel makes it possible to reduce the weight of a work piece and increases the service life of steel elements in comparison with common steel applications. The special combination of features, such as hardness, strength, and toughness, allows using elements with smaller cross-sections. The effect of different pressure levels, traverse speeds and abrasive flow rates, on cutting depth, kerf width and roughness on the cut surface of the Hardox® 500 steel was experimentally tested. In order to determine the most beneficial control parameters of the cutting process, multi-criteria optimization by means of the Gray Relation Analysis (GRA) combined with the Taguchi approach was carried out.
... Furthermore, it is a clean and environmentally friendly technology, a fundamental aspect within the field of "Green machining," and does not generate suspended particles that could affect the health of the operators. This technology offers advantages such as the recovery of abrasive particles after machining, which can be reused after treatment, and no harmful gases are generated [18]. Another important point is the retention of particles of the machined material in the pool pit, especially in composite materials, preventing them from remaining in suspension, avoiding the exposure of the operators to a harmful atmosphere. ...
The joining of dissimilar materials in a hybrid structure is a line of research of great interest at present. Nevertheless, the machining of materials with different machinability requires specific processes capable of minimizing defectology in both materials and achieving a correct surface finish in terms of functional performance. In this article, abrasive water jet machining of a hybrid carbon fiber-reinforced thermoplastics (CFRTP)/Steel structure and the generated surface finish are studied. A parametric study in two stacking configurations (CFRTP/Steel and Steel/CFRTP) has been established in order to determine the range of cutting parameters that generates the lowest values in terms of arithmetic mean roughness (Ra) and maximum profile height (Rz). The percentage contribution of each cutting parameter has been identified through an ANOVA analysis for each material and stacking configuration. A combination of 420 MPa hydraulic pressure with an abrasive mass flow of 385 g/min and a travel speed of 50 mm/min offers the lowest Ra and Rz values in the CFRTP/Steel configuration. The stacking order is a determining factor, obtaining a better surface quality in a CFRTP/Steel stack. Finally, a series of contour diagrams relating surface quality to machining conditions have been obtained.
The cutting quality of abrasive waterjet (AWJ) can be generally improved by increasing the pressure, but a higher pressure means a reduced service life of the equipment and increased manufacturing and maintenance cost. In order to obtain the required high cutting quality at a relatively low pressure of 150 MPa, the process parameters of AWJ were optimized using the response surface methodology (RSM). The surface roughness (Ra) and the kerf taper (Kt) were used to evaluate the cutting quality. The Central Composite Design (CCD) model was applied for designing the cutting experiment, and the effects of abrasive flow rate, standoff distance, and traverse speed on the machining quality were analyzed using the method of Analysis of Variance (ANOVA). By using the obtained optimal machining parameters of AWJ, the double-pass strategy was used to further promote the cutting quality. The results show that the cutting quality at the low pressure of 150 MPa can be significantly improved by optimizing the process parameters or increasing the number of cutting pass. The highest cutting quality of Ra = 4.55 μm and Kt = 0.149° can be achieved at a traverse speed of 33 mm/min, a standoff distance of 0.66 mm, and an abrasive flow rate of 339 g/min. Using the strategy of double-pass cutting, the Ra can be reduced by a maximum of 82.74%, and the greatest reduction in Kt is 59.94%, meaning the cutting quality is better when compared with that under the ultra-high pressure of 350 MPa with single-pass cutting.
Nowadays, great demands are placed on the improvement of technological processes from the perspective of quality and also from the environmental point of view. Most of the recent studies of control depth machining are realized with pressures above 100 MPa. The presented article focuses on preliminary testing of control depth cut machining by abrasive water jet technology with low pressure 50 MPa and low abrasive mass flow. The study shows promising results for the high-strength aluminum alloy AW7075. Experiments were realized using 5 levels of traverse speed (from 100–500 mm.min−1) and 4 levels of abrasives mass flow (20–50 g.min−1). The maximal mass material removal observed was 0,12 g pre one pass, and the maximal depth observed was 843 µm, both with traverse speed 100 mm.min−1 but with different abrasive mass flow. According to the obtained results can be designed more complex experiments to determine possibilities of control depth machining using an abrasive water jet with 50 MPa pressure.KeywordsAWJ MachiningControl Depth MachiningTraverse SpeedAbrasive Mass FlowGrooveSustainable Manufacturing
This paper presented optimization of machining parameters for high pressure abrasive water jet (AWJ) cutting of Hardox 500 steel utilizing WASPAS approach. Weighted aggregated sum product assessment (WASPAS) method is explored as an effective MCDM tool while solving advanced manufacturing decision making problems. It is a unique combination of two well-known MCDM approaches, i.e. weighted sum model (WSM) and weighted product model (WPM).
The tests were caried out according to the orthogonal matrix (Taguchi) L27. The control parameters of process such pressure, abrasive flow rate and traverse speed was optimized under multi-response conditions namely cutting depth and surface roughness. The optimal set of control parameters was established on the ground of the overall weighted criterium. Effects shows that optimal set for high cutting depth and small surface roughness are high pressure, high abrasive flow rate and small traverse speed. Results of research have shown that machining efficiency at keeping satisfactory level quality of cut surface can be improved this approach.
This article presents the results for the optimization of the geraniol isomerization process with the use of alum - the dodecahydrate mineral of aluminum-potassium sulfate as a catalyst. For this purpose, the Entropy / VIKOR optimization method was used. Three parameters were subjected to the process: process temperature, catalyst concentration, and reaction time. To determine the most favorable process parameters, the VIKOR method was used with the determination of weights based on entropy. The VIKOR method was used only as a numerical tool that was used to calculate the most important parameters of the process. The selected optimal parameters allowed to gain a high conversion of geraniol and selectivity of the transformation to individual reaction products.
W artykule przedstawiono możliwość rozdrabniania biomasy za pomocą laboratoryjnego młynka nożowego. Rozdrabniana biomasa może być wykorzystana w celach energetycznych np. do współspalania z węglem w piecach fluidalnych. Jako biomasę wykorzystano wierzbę energetyczną o dwóch grubościach gałęzi (ok. 0,75 mm i 1,25 mm) oraz słomę. Młynek laboratoryjny wyposażony był w dwa przemienne sita o oczkach 0,75 mm i 1 mm. Próbki rozdrabniano w czasie 30, 60 i 90 sekund. Rozdrobniony pył drzewny z wierzby energetycznej poddano analizie ziarnowej na elektronicznym analizatorze IPS. Obliczono również wydajność młynka podczas mielenia danej biomasy. Największą wydajność uzyskano podczas mielenia grubych gałęzi wierzby przy zastosowaniu sita dolnego o oczkach 1 mm, a najmniejszą podczas mielenia słomy.
W artykule przedstawiono dane dotyczące produkcji odlewów w latach 2000-2017 zarówno w skali światowej, jak i w Polsce, oraz w odniesieniu do czołowych producentów odlewów. W opracowaniu uwzględniono podstawowe rodzaje stopów odlewniczych, a także dane dotyczące ilości odlewni w analizowanym okresie czasu.
Z porównania danych wynika, że produkcja odlewów na świecie w latach 2000-2017 zwiększyła się z około 65 mln ton do około 110 mln ton; analogiczne dane odnoszące się do polskiego przemysłu odlewniczego to ok. 750 tys. ton i ok. 1040 tys. ton. Największym producentem odlewów na świecie, niezmiennie od 2001 roku pozostają Chiny. Średnioroczne tempo wzrostu produkcji odlewniczej na świecie wyniosło w rozpatrywanym okresie ok. 3,1% (w Polsce ok. 1,9%); zarówno w skali światowej jak w odniesieniu do Polski było ono wyraźnie większe w latach 2000-2010, aniżeli w kolejnych 7 latach. W największym stopniu wzrosła produkcja odlewów ze stopów aluminium oraz z żeliwa sferoidalnego. Udział Polski w światowej produkcji odlewniczej w roku 2017 wynosił 0,94%.
Nowadays is placed great emphasis on miniaturization and reduction of weight in many industrial sectors. Application of abrasive water jet to produce thin-walled components hide big potential for future applications, due to small lateral force and absence of heat-affected zone. The presented article is focused on the possibility of creating thin-walled ribs using an abrasive water jet. An experimental procedure was selected to produce the thinnest possible rib in aluminum alloy AW 6060. Ribs were created by two passes of the AWJ with changing of the pitch between two passes. Due to minimal lateral force in the process as possible to create a rib with an average width of 0.4 mm with a height, more than 8 mm. Metallography analysis was performed for a closer look on the subsurface layers of the created rib and root of the rib. Results have the potential to extend knowledge in the field of abrasive water jet machining of thin-walled components.
The presented article is focused on the abrasive water jet machining of tool steel material. Selected tool steels Uddeholm Dievar and Böhler K110 were machined and final pockets were evaluated based on the side angle of the pocket. Sequentially were created pockets with increasing depth from 1 to 5 mm for both materials. Evaluation of pocket angle is crucial factor for determination of machining allowance for finishing cuts. Also metallography analysis for both materials was created for observation of removal process and for detection of cracks produced during abrasive water jet machining. In terms of corrosion of presented tool steels can be stated that due to higher number of alloying elements is corrosion on machined surface acceptable for further processing of created shapes. Obtained results can extend application possibilities of AWJ milling for rough machining of tool steels, especially for thin-walled components with reduction of induced residual stresses and deformations of shapes.
This work describes the research aimed at determining the value of the basic parameters of fish cutting on treatment with a high-pressure water jet. Assuming a constant feed speed, distance of the nozzle from the processed raw material, and spray angle of the water jet for six diameters of the water nozzles, the supply pressure value was determined. Supply pressure at which the water stream has enough energy to fully cut the muscle flap is also determined. The tests were carried out on samples obtained from rainbow trout, considering the size of the carcasses and the place of cutting. Analysis of the obtained results showed that both the size of the carcass and the cutting site affect the value of the supply pressure. However, regardless of this, the full cut of the lobe without the skin can be obtained by feeding the jet with a pressure of 3.5 MPa. This amount of pressure can easily be achieved using a Karcher pressure washer. To effectively apply this technology to the fish processing industry, it is necessary to extend the tests with further processing parameters such as the feed speed of the nozzle.
Corundum-based abrasives are commonly used for cutting extremely hard materials like e.g. ceramics by means of abrasive waterjets. Due to a reduced lifetime of the used focusing tubes, this type of abrasive is only applied under special consideration of economic circumstances. The cutting centres which use this technology retain only a small amount of used abrasives because of the limited application of this grain type. Nevertheless, observing the disintegration of particles which have interacted with mostly advanced materials is of scientific interest. Garnet-based abrasives are commonly classified in different grain size classes after sieving to evaluate their recycling potential. Based on a feasibility study, this paper will present some results on achieved cutting data and also shows the geometrical change of the used focusing tubes which was realized by non-destructive examination. The mass loss factor of the used focusing tubes was calculated for different corundum materials and compared with the commonly used in AWJ machining abrasive, garnet. Additionally, cutting and recycling properties of the tested corundum-based abrasive was tested. The disintegration properties of the corundum-based abrasive were monitored by sieving and optical test methods. Particle identification after cutting process (grain or chip) was realized by energy-dispersive X-ray microanalysis (EDX). Finally, the results obtained were used to make a rough calculation for lifetime estimations of the focusing tubes related to the observed wear process.
The paper concern to the impact of the Abrasive Water Suspension
Jet (AWSJ) limestone cutting process parameters, such as abrasive flow rate,
diameter and length of the forming nozzle jet under reduced pressure on the
depth of cut. Achieving such a high efficiency in the processing of this rock
results from the use of circular motion of the liquid to create a stream. This has
become possible due to the replacement of a low-efficiency injector mixer with a
new mixer in which the hydro-abrasive mixture is generated directly under high
pressure. The conducted research allowed to determine the best geometric
dimensions of the working nozzle and abrasive flow rate to achieve the best
machining effects were achieved.
Experimental research on high-pressure abrasive water-jet cutting of a popular titanium alloy, grade 5 (Ti6Al4V), is presented. Three types of abrasive material, garnet, olivine, and a cheaper alternative—crushed glass abrasive, were investigated. The influence of basic cutting parameters such as traverse speed and concentration of abrasive on cutting depth was shown, as was the effect of the ratio of the diameter of the water nozzle to the diameter of the focusing tube on the cutting depth. A slower traverse speed resulted in a deeper depth of cut for all abrasive materials. The variation of cutting depth became irrelevant when the concentration of the jet was increased. On basic regression analysis, the cutting depth control models were formulated. The cutting efficiency and the focusing tube wear for all abrasives were compared in order to determine the degree of effectiveness for each abrasive.
The study on the effect of abrasive water jet machining process parameters on micro alloyed steel surface roughness was described. Taguchi method to predict machining parameters of due to minimum surface roughness was used. The influence of pressure, abrasive flow rate and traverse speed on the Rz and Rmax roughness parameters were presented. The optimum combination of processing parameters was established. Verified parameters were tested and the achieved results were compared to predicted values. This method allows limiting the amount of research needed to achieve the desired test results, thereby reducing the time as well as the cost required to carry them out. The Taguchi signal/noise (S/N) ratio enables the assessment of the relevance of the impact of various parameters on the process, which is still not well enough understood.
The paper presents the fractal analysis application for a simple evaluation of the quality of water jet treated surfaces, especially after abrasive water jet
cutting. This analysis will enable the elimination of subjective assessments of treated surfaces. This will ensure a clear estimate of the quality of the
surface and the ability to objectively compare the quality of the cutting edge obtained by using different cutting parameters.
Existing models of predict the abrasive water jet cutting effects, does not give satisfactory results in a wide area of parameter changes, in particular for different, unusual materials. This implies the need to carry out extensive research in order to expand the empirical database. To optimize the process can be used modern methods referred to as Design of Experiment (DoE). One of the methods to determine the effect of parameters on the controlled different technological processes is orthogonal array design, also called the Taguchi approach. This method allows to limit the amount of research needed to achieve the desired test results, reducing the time required course for their performance and at the same time their costs. Characterized by Taguchi ratio signal / noise (S / N) enables the assessment of the significance of the impact of various parameters on the process, which is still not well enough understood. The article discusses one method for cutting optimization of aluminum alloy by high pressure abrasive water jet.
The paper deals with the investigating the possibility of using vibrations as a potential source of information for the detection of the malfunctions during the abrasive supplying and focusing tube wear in the process of AWJ. The tested material was the stainless steel AISI 309. Variable factors in the experiment were the abrasive mass flow ma and the focusing tube diameter df. The scanned vibration signal of the material was subjected to frequency analysis. With the increase of the abrasive mass flow, the shift of the amplitudes will follow the opposite direction and decrease. Frequency spectra of all assessed signals are similar by shape in the high-frequency area.
Existing models of predict the abrasive water jet cutting effects, does not give satisfactory results in a wide area of parameter changes, in particular for different, exotic materials. This implies the need to carry out extensive research in order to expand the empirical database. To optimize the process can be used modern methods referred to as Design of Experiment. One of the methods to determine the effect of parameters on the controlled different technological processes is the Taguchi approach. This method allows to limit the amount of research needed to achieve the desired test results, reducing the time required course for their performance and at the same time their costs. Characterized by Taguchi ratio signal / noise (S / N) enables the assessment of the significance of the impact of various parameters on the process, which is still not well enough understood. The article discusses one method for optimization of cutting tool steel, by high pressure abrasive water jet.
A method for the design of a technology for the abrasive waterjet cutting of materials is based on the determination of the constant of cuttability of materials using an abrasive waterjet Kawj according to four different versions. Version A, where three deformation parameters are measured on the test cut/sample, namely selected depth hx [mm], local roughness Rax [μm] at depth hx and local deviation of the cut trace from the normal plane Yretx at depth hx. Version B, where merely two deformation parameters are measured, namely the reference depth het [mm] and deviation of the cut trace from the normal plane Yretx [mm] or, according to version C, where one parameter is mearured, namely either the ultrasonic wave speed vLUZ [m · s–1] or Young's modulus Emat [MPa]; Kawj being calculated from relevant deformation parameters. The last option is version D, where the design of the whole technology is carried out by calculation of Kawj according to the Young's modulus Emat or according to the ultrasonic wave speed vLUZ of the cut material.
The wear of the focusing tube is a very important feature of the abrasive water jet machining. Of all rejected focusing tubes, 85% are worn. Similary, the age of focusing tube influences the cut geometry and quality of machined surface. With regard to the stated, wearing of the focusing tube is subject of this paper. Focusing tube outlet diameter was measured as well as its influence on the surface quality.
This paper presents the modelling of a contact problem in the operation of technological production of objects. An incremental model of the contact problem for movable elasto/visco-plastic body for spatial states (3D) is being considered. Geometrical contact conditions (GCC) for the case of a deformed object and a rigid or elastic tool, with a rotation and translation of the bodies are introduced. A GCC form used in numeric calculations is determined. Dependences between increments of unit forces in the contact area of bodies is introduced. Basic incremental equations of the edge displacement in the reversible and nonreversible zone are defined. The description of a geometrical contact conditions and friction conditions in the ranges of stick-slip are considered. The models obtained are used to a variational formulation of a contact problem with the application of a method of finite elements and to a numerical analysis of the contact problem.
A bar on the Brazos River near Calvert, Texas, has been analyzed in order to determine the geologic meaning of certain grain size parameters and to study the behavior of the size fractions with transport. The bar consists of a strongly bimodal mixture of pebble gravel and medium to fine sand; there is a lack of material in the range of 0.5 to 2 mm, because the source does not supply particles of this size. The size distributions of the two modes, which were established in the parent deposits, are nearly invariant over the bar because the present environment of deposition only affects the relative proportions of the two modes, not the grain size properties of the modes themselves. Two proportions are most common; the sediment either contains no gravel or else contains about 60% gravel. Three sediment types with characteristic bedding features occur on the bar in constant stratigraphic order, with the coarsest at the base. Statistical analysis of the data is based on a series of grain size parameters modified from those of Inman (1952) to provide a more detailed coverage of non-normal size curves. Unimodal sediments have nearly normal curves as defined by their skewness and kurtosis. Non-normal kurtosis and skewness values are held to be the identifying characteristics of bimodal sediments even where such modes are not evident in frequency curves. The relative proportions of each mode define a systematic series of changes in numerical properties; mean size, standard deviation and skewness are shown to be linked in a helical trend, which is believed to be applicable to many other sedimentary suites. The equations of the helix may be characteristic of certain environments. Kurtosis values show rhythmic pulsations along the helix and are diagnostic of two-generation sediments.
The thread rolling is difficult technological process. Improve quality and contemporary reduce manufacture cost of the trapezoidal thread requires acquaintances of physical phenomena observed in the contact zone between rolls and deform work-pieces. Therefore, in this paper the physical and mathematical models of deformations (displacements and strains) and stress in the cold process of trapezoidal thread rolling, were developed. The process is considered as a geometrical and physical non-linear, initial as well as boundary value problem. The phenomena on a typical incremental step were described using a step-by-step incremental procedure, with an updated Lagrangian formulation. The state of strains was described by Green-Lagrange's tensor, while the state of stress by the second symmetrical Pioli-Kirchhoff's tensor. The object was treated as an elastic (in the reversible zone) and visco-plastic body (in non-reversible zone) with mixed hardening. The variational equation of motion in three dimensions for this case was proposed. Then, the finite elements methods (FEM) and dynamic explicit method (DEM) were used to obtain the solution. The application developed for in the ANSYS programme, which provides a complex time analysis for displacement, strains and stresses occurring in the object. The recommendations concern modeling the trapezoidal thread rolling process, where reduce degrees of freedom in numerical model is very important and provide convergence calculated results for maximum stress and strain values in the thread surface layer, were elaborated. The influence a various process conditions on the states deformation and stress for examples calculations, were presented. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Grain size analysis is an essential tool for classifying sedimentary environments. The calculation of statistics for many samples can, however, be a laborious process. A computer program called GRADISTAT has been written for the rapid analysis of grain size statistics from any of the standard measuring techniques, such as sieving and laser granulometry. Mean, mode, sorting, skewness and other statistics are calculated arithmetically and geometrically (in metric units) and logarithmically (in phi units) using moment and Folk and Ward graphical methods. Method comparison has allowed Folk and Ward descriptive terms to be assigned to moments statistics. Results indicate that Folk and Ward measures, expressed in metric units, appear to provide the most robust basis for routine comparisons of compositionally variable sediments. The program runs within the Microsoft Excel spreadsheet package and is extremely versatile, accepting standard and non-standard size data, and producing a range of graphical outputs including frequency and ternary plots. Copyright © 2001 John Wiley & Sons, Ltd.
Significance of Barton Garnet and Olivine Evaluation at Abrasive Waterjet Cutting by Factor Analysis
- S Hloch
- J Valicek
Hloch, S., Valicek, J. (2007). Significance of Barton Garnet and Olivine Evaluation at Abrasive Waterjet Cutting by Factor Analysis. Nonconventional
Technologies Review, 4(9), 25-30.
Abrasives for AWJ Cutting
- P Martinec
- J Foldyna
- L Sitek
- J Ščučka
- J Vašek
Martinec, P., Foldyna, J., Sitek, L., Ščučka, J., Vašek, J. (2002). Abrasives for
AWJ Cutting. Institute of Geonics, Ostrava, Czech Republic 2002.
Abrasive grain breakage process during the high pressure waterjet formation
- A Perec
Perec, A. (2011). Abrasive grain breakage process during the high pressure
waterjet formation. 2011 WJTA-IMCA Conference. Water Jet Technology
Association, 19-21 September 2011, paper C1.
Comparison of abrasive grain disintegration during the jet formation abrasive water jet and abrasive slurry injection jet
- A Perec
Perec, A. (2012). Comparison of abrasive grain disintegration during the jet
formation abrasive water jet and abrasive slurry injection jet. 21st International Conference. on Water Jetting. British Hydromechanic Research
Group, 19-21 September 2012, 319-327.
Recycling capacity of abrasives in abrasive waterjet cutting
- N S Guo
- H Louis
- G Meier
- J Ohlsen
Guo, N.S., Louis, H., Meier, G., Ohlsen, J. (1992). Recycling capacity of abrasives in abrasive waterjet cutting. Proceedings of the 11 th International
Conference on Jet Cutting Technology. St. Andrews, Scotland, 503-523.