Search Results for material extrusion

This article is a review of the material extrusion-based ceramic additive manufacturing (MECAM) processes. The discussion begins with details of extrusion with filament and paste, covering the most popular variants of paste extrusion-based MECAM techniques that can be differentiated based on paste type and the method of shape retention of the deposited layer: extrusion freeforming, robocasting ceramic on-demand extrusion, and freeze-form extrusion fabrication. The article then focuses on post-processing considerations and the mechanical properties of sintered ceramic parts. It concludes with information on innovation opportunities in ceramic additive manufacturing, such as incorporating UV-curing and gelation in the process and producing geometrically complex structures from shapeable green bodies.

Material extrusion systems are the most common types of additive manufacturing systems, also known as three-dimensional (3D) printers. This article focuses on the general 3D printing processes as can be demonstrated and manipulated in desktop printers. The discussion includes details of the components involved in material extrusion as well as the melt extrusion solidification (during cooling) process, the underlying mechanism of road bonding, and the factors affecting good part quality. The discussion also covers support material, postprocessing, and road-quality considerations and the addition of infill in melt extrusion to the hollow spaces inside an object to give it structural strength. Information is also provided on different materials and associated material properties that affect the rate the printer is able to advance and retract material, thereby affecting the quality and rate at which a part is printed. The final section provides information on the mechanism of viscous extrusion 3D printing.

Additive manufacturing is a collection of manufacturing processes, each of which builds a part additively based on a digital solid model. The solid model-to-additive manufacturing interface and material deposition are entirely computer-controlled. The traditional additive manufacturing applications have been used for low production runs of parts with complex shapes and geometric features. Additive manufacturing is also used for topology optimization and it impacts the process and supply chain. This article discusses processes, including vat photopolymerization, material jetting, powder bed fusion, directed energy deposition, material extrusion, binder jetting, and sheet lamination.

The article presents an in-depth discussion on the various additive manufacturing techniques such as binder jetting, directed-energy deposition, material extrusion, material jetting, powder-bed fusion, sheet lamination, and vat polymerization processes. This article then discusses the different critical material aspects of additively manufactured medical devices, beginning with the preprinting phase (material consistency and recycling), the printing phase (build orientation), and the postprinting phase (part evaluation, biocompatibility, and sterilization) with supporting materials.

This article focuses on four industrial additive manufacturing approaches that are used to create polymer parts. The first section focuses on material extrusion, providing information on lumped-parameter material flow models and higher-fidelity models developed to estimate temperature distribution. The second section covers polymer powder-bed sintering/ fusion, discussing the different levels of scale used to address modeling and the impact of process settings: thermodynamics at the powder-bed surface, consolidation of adjacent particles in the fusion process, and fusion and molecular-level behavior within particles. The third section on vat photopolymerization (VPP) discusses two primary approaches to modeling VPP processes, namely a lumped-parameter approach to estimate cured regions in the vat, known as the Jacobs model, and a high-fidelity, continuum approach that uses finite-element methods. The final section is devoted to material jetting, focusing on simulations used to study droplet generation at the nozzle and droplet impact.

Additive manufacturing (AM), or three-dimensional (3D) printing, has been widely used for biomedical devices due to its higher freedom of design and its capability for mass customization. Additive manufacturing can be broadly classified into seven categories: binder jetting, directed energy deposition (DED), material extrusion, material jetting, powder-bed fusion (PBF), sheet lamination, and vat photopolymerization. Due to their capability for manufacturing high-quality parts that are fully dense, PBF and DED are the most widely used groups of AM techniques in processing metals directly. In this article, the processing of titanium and its alloys by PBF and DED is described, with a specific focus on their use in biomedical devices. The article then covers the density and mechanical properties of both commercially pure titanium and titanium-aluminum-vanadium alloy. Lastly, the challenges and potential of using new titanium-base materials are discussed.

The additive manufacturing technologies in the casting of precious metals are divided into two groups: indirect metal methods and direct metal methods. Besides providing a process overview of both of these methods, the focus of this article is on the characteristics, process steps, applications, and advantages of direct metal methods, namely laser melting, material extrusion, binder jetting, material jetting, and vat photopolymerization methods.

Additive manufacturing (AM) is a revolutionary technology that fabricates parts layerwise and provides many advantages. This article discusses polymer AM processes such as material extrusion, vat photopolymerization (VPP), powder-bed fusion (PBF), binder jetting (BJ), material jetting (MJ), and sheet lamination (SL). It presents the benefits of online monitoring and process control for polymer AM. It also introduces the respective monitoring devices used, including the models and algorithms designed for polymer AM online monitoring and control.

According to International Organization for Standardization (ISO)/ASTM International 52900, additive manufacturing (AM) can be classified into material extrusion, material jetting, vat photo polymerization, binder jetting, sheet lamination, powder-bed fusion (PBF), and directed-energy deposition. This article discusses the processes involved in polymer powder 3D printing using laser fusion/ sintering and fusing agents and energy, as well as the thermally fused PBF. It provides information on polymer powder parameters and modeling, the powder-handling system, powder characterization, the flowability of powder feedstock, and polymer part characteristics. The article describes the types of polymers in PBF, the processes involved in powder recycling, and the prospects of PBF in AM. In addition, the biomedical application of polyether ether ketone (PEEK) is also covered.

Additive manufacturing (AM) provides exceptional design flexibility, enabling the manufacture of parts with shapes and functions not viable with traditional manufacturing processes. The two paradigms aiming to leverage computational methods to design AM parts imbuing the design-for-additive-manufacturing (DFAM) principles are design optimization (DO) and simulation-driven design (SDD). In line with the adoption of AM processes by industry and extensive research efforts in the research community, this article focuses on powder-bed fusion for metal AM and material extrusion for polymer AM. It includes detailed sections on SDD and DO as well as three case studies on the adoption of SDD, DO, and artificial-intelligence-based DFAM in real-life engineering applications, highlighting the benefits of these methods for the wider adoption of AM in the manufacturing industry.