Table 3 - uploaded by Shoufeng Yang
Content may be subject to copyright.
Source publication
Interest in multifunctional structures made automatically from multiple materials poses a challenge for today's additive manufacturing (AM) technologies; however the ability to process multiple materials is a fundamental advantage to some AM technologies. The capability to fabricate multiple material parts can improve AM technologies by either opti...
Context in source publication
Similar publications
A preliminary tensile test was performed to evaluate the mechanical properties of cobalt-chromium (Co-Cr) alloys fabricated by three new manufacturing processes: metal milling, milling for soft metal, and rapid prototyping (n = 6). For comparison, the three alloy materials were also used to fabricate specimens by a casting procedure. In all groups...
Rapid prototyping procedures make it possible to produce relatively complicated geometries based on the computer 3D model of products in relatively short time. This requires that the respective product features have good quality, good mechanical properties, dimensional accuracy and precision. However, the number of available materials that can be u...
Citations
... Currently, inkjet printing is the only technique among various AM processes capable of successfully printing multimaterial fuel cell components. However, research efforts are underway to integrate various additive manufacturing methods and enable the multi-material fabrication of components with enhanced thermal, mechanical, chemical, and electrical properties [131]. • Beyond material challenges, the resolution of AM techniques limits their full potential. ...
Fuel cells offer high-efficiency power production compared to internal combustion (IC) engines and gas/steam turbines. They are also very clean and come in several types, including PEM fuel cells, solid oxide fuel cells, direct methanol fuel cells, alkaline fuel cells, molten carbonate fuel cells, and phosphoric acid fuel cells. This diversity enables a broad market for decentralized power supply—both stationary and vehicular. In recent years, significant progress has been made in using additive manufacturing (AM) to fabricate fuel cell components such as electrolytes, electrodes, and casings. AM has revolutionised fuel cell fabrication by providing a sustainable process for producing parts with complex geometries, high material flexibility, and enhanced efficiency. This review aims to summarize the importance and current status of AM in fuel cell production. Various AM techniques (such as vat photopolymerization, material jetting, and powder bed fusion (PBF)) used in manufacturing different fuel cell components are discussed, along with recent advancements in materials and their corresponding properties. The review critically analyses the state of the art, highlighting the advantages and limitations of different techniques. Furthermore, this analysis extends to identifying suitable solutions to address challenges in fuel cell fabrication, providing valuable insights for researchers and engineers focused on clean energy production. This review article will benefit researchers interested in exploring the scope of AM in fuel cells.
... The printed 'green' part is then subjected to post-printing processing which may include stages like curing, debinding, and sintering. Binder jetting has demonstrated it capability of being a material agnostic processing technique, having the capability of printing metal alloys and ceramics with good resolution and without the problems encountered by SLM as discussed earlier [10]. Raza et al. processed Inconel 718 by SLM and obtained a coarser grain structure as compared to binder jetting, which was attributed to the formation of spherical MC type carbides and γ/Laves phases during SLM processing of Inconel 718 [11]. ...
... The studies of Derby et al. suggested that the range of the Z number for stable jettability should be such that Zϵ [1,10]. The range of the Z for the three liquid binders was calculated to be in the range of 74 to 78, but consistent jetting of the liquid binders was observed as has been also reported by Tekin et al. and Vadillo et al. [37,38]. ...
Binders used in binder jetting often pose health and environmental risks during processing and post processing operations. The print-heads which are used to deposit binder selectively on the feedstock are prone to clogging, despite the trend of print-heads being highly customised to suit different kinds of binders. These factors often hide the advantages of binder jetting as an additive manufacturing process, especially its scalability and its faster printing rates in comparison to powder bed fusion methods. The work presented here takes a step back and focuses on the development of an aqueous, polyvinyl alcohol (PVA)-based liquid binder that is easy to manufacture and store, safe to handle, and can be reliably jetted to print parts. The feedstock considered was Inconel 718, a nickel-based super alloy which can be effectively processed by binder jetting without niobium segregation. PVA was added to the Inconel 718 powder in dry, granular form to manufacture a modified feedstock. The study also investigated the role of molecular weight of the PVA used, sintering environments and post-processing methods like hot isostatic pressing (HIP) on process responses like part densification, tensile strength, and hardness. Three different types of PVA were chosen which had molecular weights 10,000 g/mol (low molecular weight or LMW), 26,000 g/mol (medium molecular weight or MMW), and 84,000 g/mol (high molecular weight or HMW). The compatibility of the liquid, aqueous PVA-based binders with virgin Inconel 718 was examined by measuring the contact angle. The liquid, aqueous binder having MMW PVA reported better wetting with the Inconel 718 powder with a wetting angle of 26.6 which was lower than the wetting angle of 42.4°, seen in case of a commercial resin-based binder. The green strength reported by the MMW PVA liquid binder was 220 kPa which was higher than the other two PVA-based liquid binders. Green parts, upon successful printing, were sintered at 1260 °C. It was observed that a part printed using MMW PVA had a densification of 96.16% when sintered in 99.98% by volume argon gas, which increased to 98.96% after undergoing HIP. The same part reported a densification of 88.69% when sintered in a 95% by volume N2 and 5% by volume H2 gaseous environment, which was later attributed to the uptake of nitrogen by the chromium present in Inconel 718, which prevented necking between particles. Tensile specimens printed using MMW PVA, sintered in a 99.98% argon environment, showed the highest ultimate tensile strength of 220 MPa, which increased to 1010 MPa after the HIP process, which can be compared to commercially available Inconel 718.
... In 3D printing, latest advances have allowed materials to be positioned more accurately and with more flexibility, which has greatly benefited 4D printing [581]. The materials employed for 4D printing are usually known as smart materials, because they can alter their characteristics as time passes (Figure 7) [582]. ...
... This orientation made the transverse swelling four times larger than the longitudinal swelling, which enabled the programming of the printed 4D texture. Another possibility is to limit the hydrogels in a single direction with rigid materials, causing an anisotropic expansion of the hydrogel [581]. Films of stearoyl ester (CSE) cellulose have been prepared, and these hydrophobic films exhibited a more accurate and rapid reaction than the previous films [584]. ...
The 3D bioprinting technique has made enormous progress in tissue engineering, regenerative medicine and research into diseases such as cancer. Apart from individual cells, a collection of cells, such as organoids, can be printed in combination with various hydrogels. It can be hypothesized that 3D bioprinting will even become a promising tool for mechanobiological analyses of cells, organoids and their matrix environments in highly defined and precisely structured 3D environments, in which the mechanical properties of the cell environment can be individually adjusted. Mechanical obstacles or bead markers can be integrated into bioprinted samples to analyze mechanical deformations and forces within these bioprinted constructs, such as 3D organoids, and to perform biophysical analysis in complex 3D systems, which are still not standard techniques. The review highlights the advances of 3D and 4D printing technologies in integrating mechanobiological cues so that the next step will be a detailed analysis of key future biophysical research directions in organoid generation for the development of disease model systems, tissue regeneration and drug testing from a biophysical perspective. Finally, the review highlights the combination of bioprinted hydrogels, such as pure natural or synthetic hydrogels and mixtures, with organoids, organoid–cell co-cultures, organ-on-a-chip systems and organoid-organ-on-a chip combinations and introduces the use of assembloids to determine the mutual interactions of different cell types and cell–matrix interferences in specific biological and mechanical environments.
... Among the various AM technologies, additive material extrusion (MEX) stands out for its vast potential to produce multi-material components without additional process steps, thanks to the feasibility of combining different materials within a single layer. However, adhesion at the multi-material interface is typically low, posing challenges for product developers and manufacturers [1][2][3]. ...
Additive manufacturing provides new possibilities in product design compared to traditional manufacturing processes. Particularly additive material extrusion offers the freedom to combine multiple materials in a single component without additional steps. However, combining multiple materials often leads to reduced adhesion, which can hinder the creation of high-strength designs. This issue can be largely mitigated using the geometric freedom of additive manufacturing to produce interlocking structures. This publication investigates the use of lattice structures as interlocking bonds in multi-material applications. The aim is to aid the design of suitable lattice structures by collecting geometric freedoms of lattices, application requirements, and manufacturing constraints, for this information to be used in suitable designs in the future. Initially, the general design freedoms of lattice structures are compiled and explained. Subsequently, these design freedoms are narrowed down based on the specific requirements for interlocking bonds and the limitations imposed by geometry and material combinations during manufacturing. The publication concludes with design recommendations that can be used as the basis for interlock bonds. Suitable lattice designs should aim for high interconnectivity, interconnected porosity, and a high number of similar strut structures, all the while maintaining low dimensions in the interface direction.
... It employs a combination of inkjet printing and infrared heating to fuse powdered thermoplastics, layer by layer selectively. MJF/ PBF can produce parts with great detail and exceptional mechanical properties, making it suitable for functional prototypes and end-use parts [89][90][91][92]. Each layer's thickness varies based on the material, typically ranging from tens of microns to 100 µm for metals and 50-150 µm for polymers [93]. ...
This review article provides a deep dive into the diverse landscape of Additive Manufacturing (AM) technologies and their significant impact on the automotive and aviation sectors. It starts by exploring various AM methodologies such as Fused Deposition Modeling (FDM), Stereolithography (SLA), Digital Light Processing (DLP), Selective Laser Sintering (SLS), Metal Jet Fusion (MJF), Binder Jetting (BJ), and Directed Energy Deposition (DED), with a specific focus on their applicability, strengths, and challenges within these industries. The article then delves into the practical applications of AM in rapid prototyping, functional part production, and component repair. The results highlight the versatility and precision of SLA and DLP, the strength and durability of SLS, and the potential of metal-based technologies like LPBF, SLM, EBM, and DMLS in manufacturing critical components. The integration of AM with automotive and aviation design underscores the transformative nature of these technologies, driving advancements in lightweight, intricate, and high-performance components. The review concludes by emphasising AM's significant opportunities and acknowledging the ongoing challenges in material properties, post-processing, and production scalability, thereby underscoring the necessity for future research and innovation in these sectors.
... Commercially accessible alloys for AM were first developed for traditional production methods (Anca et al., 2011). Nevertheless, considering the complex physicalchemical transformations that AM requires and which differ significantly from conventional production techniques, this presents significant hurdles for AM (Vaezi et al., 2013;Zhou et al., 2021). Because of the extremely localized and heterogeneous thermal history associated with material deposition, the resulting structures exhibit significant variability, especially when combined with the presence of flaws that compromise the integrity and performance of produced components (Svetlizky et al., 2021). ...
Purpose
This study aims to develop a holistic method that integrates finite element modeling, machine learning, and experimental validation to propose processing windows for optimizing the laser powder bed fusion (LPBF) process specific to the Al-357 alloy.
Design/methodology/approach
Validation of a 3D heat transfer simulation model was conducted to forecast melt pool dimensions, involving variations in laser power, laser scanning speed, powder bed thickness (PBT) and powder bed pre-heating (PHB). Using the validated model, a data set was compiled to establish a back-propagation-based machine learning capable of predicting melt pool dimensional ratios indicative of printing defects.
Findings
The study revealed that, apart from process parameters, PBT and PHB significantly influenced defect formation. Elevated PHBs were identified as contributors to increased lack of fusion and keyhole defects. Optimal combinations were pinpointed, such as 30.0 µm PBT with 90.0 and 120.0 °C PHBs and 50.0 µm PBT with 120.0 °C PHB.
Originality/value
The integrated process mapping approach showcased the potential to expedite the qualification of LPBF parameters for Al-357 alloy by minimizing the need for iterative physical testing.
... Although the technology depth of the clothing industry is medium, the breadth is low, and the influence is limited. However, 3D-printing technology has significant advantages in clothing customization and rapid response to market demands [65]. It is suggested that through cooperation with fashion designers and brands, the application of 3D printing in the customized production of clothing should be enhanced, the market coverage should be expanded, and the market acceptance should be enhanced to make up for the shortcomings of the market application research of apparel 3D-printing technology. ...
In today’s increasingly competitive globalization, innovation is crucial to technological development, and original innovations have become the high horse in the fight for market dominance by enterprises and governments. However, extracting original innovative technologies from patent data faces challenges such as anomalous data and lengthy analysis cycles, making it difficult for traditional models to achieve high-precision identification. Therefore, we propose a Multi-Dimensional Robust Stacking (MDRS) model to deeply analyze patent data, extract leading indicators, and accurately identify cutting-edge technologies. The MDRS model is divided into four stages: single indicator construction, robust indicator mining, hyper-robust indicator construction, and the pioneering technology analysis phase. Based on this model, we construct a technological development matrix to analyze core 3D-printing technologies across the industry chain. The results show that the MDRS model significantly enhances the accuracy and robustness of technology forecasting, elucidates the mechanisms of technological leadership across different stages and application scenarios, and provides new methods for quantitative analysis of technological trends. This enhances the accuracy and robustness of traditional patent data analysis, aiding governments and enterprises in optimizing resource allocation and improving market competitiveness.
... Multi-material additive manufacturing (MMAM) introduces a new design degree of freedom through the strategic placement of compatible alloys within a heterogenous component. This approach results in multi-functional, cost-effective parts with tunable local characteristics, reduced reliance on vulnerable joint systems and adaptability to combined environmental constraints [1][2][3]. Laser powder bed fusion (L-PBF) also stands out as an MMAM method due to its near-net shape fabrication capabilities [3,4] that promote raw material efficiency and limit alloy migration through interdiffusion [5,6]. The high in-plane print resolution [3,5] due to the incremental deposition also allows the fabrication of components with unconventional property combinations, which is demonstrated in multi-functional metal metamaterials that are only achieved due to powder compositions that are customised for L-PBF [7,8]. ...
This study demonstrates the successful fabrication of a multi-material 18Ni(300) maraging steel – CoCrMo alloy using laser powder bed fusion (L-PBF), which in its as-built state, displays suboptimal mechanical performance. Addressing this, we propose different heat treatments that mutually enhance the properties of both alloys. Comparative analysis of texture development, precipitation sequence and mechanical properties of the dual structures at different scales has been conducted. The results indicate the cooperative strengthening of intragranular γ–ϵ transformation in CoCrMo, and Ni3Ti precipitation in maraging steel. Adding the solution treatment also balanced the formation of acicular Ni3Ti clusters with (Fe, Ni, Co)2(Ti, Mo) precipitates, and revealed that chemical segregation influences austenite reversion. Initial evidence of local grain variant selection has been revealed in as-built samples due to thermal cycling and austenite reversion, which generates residual stresses, recoil forces and convective flow. Surprisingly, the missing variants can also be inherited after heat treatment with insufficient solution temperatures.
... This paper aims to propose a data-driven additive manufacturing system that can assist in setting parameters for different types of products. The proposed system leverages machine learning algorithms to learn from historical data and predict optimal settings for similar products, thereby reducing human involvement and errors (Goh et al. 2020;Liu et al. 2020;Ngo et al. 2018;Vaezi et al. 2013). It's worth noting that some 3D printers have the capability to produce objects with multiple colours, allowing for greater design flexibility. ...
... One of the advantages of inkjet printing is the simultaneous deposition of multi-materials. Therefore, a printed part can have selective mechanical properties, opacities, and colors [106]. For example, a robot can be constructed with inkjet materials with different mechanical stiffness (i.e., elastic modulus), enabling a programmable mechanical response [107] to temperature, electrical stimuli, or oscillating magnetic fields. ...
Hydrogels with particulates, including proteins, drugs, nanoparticles, and cells, enable the development of new and innovative biomaterials. Precise control of the spatial distribution of these particulates is crucial to produce advanced biomaterials. Thus, there is a high demand for manufacturing methods for particle-laden hydrogels. In this context, 3D printing of hydrogels is emerging as a promising method to create numerous innovative biomaterials. Among the 3D printing methods, inkjet printing, so-called drop-on-demand (DOD) printing, stands out for its ability to construct biomaterials with superior spatial resolutions. However, its printing processes are still designed by trial and error due to a limited understanding of the ink behavior during the printing processes. This review discusses the current understanding of transport processes and hydrogel behaviors during inkjet printing for particulate-laden hydrogels. Specifically, we review the transport processes of water and particulates within hydrogel during ink formulation, jetting, and curing. Additionally, we examine current inkjet printing applications in fabricating engineered tissues, drug delivery devices, and advanced bioelectronics components. Finally, the challenges and opportunities for next-generation inkjet printing are also discussed.
Graphical Abstract
