This article focuses on binder-jetting technologies in additive manufacturing (AM) that produce metal artifacts either directly or indirectly. The intent is to focus on the most strategic and widespread uses of the binder jetting technology and review some of the challenges and opportunities for that technology. The discussion includes a historical overview and covers the major steps involved and the advantages of using the binder jetting process. The major steps of the process covered include printing, curing, de-powdering, and sintering.

The highly irregular morphologies of ceramic powder particles due to their process history present a challenge to binder jetting additive manufacturing (BJ-AM) ceramic powder feedstock processability, but knowledge of powder metallurgy of ceramics benefits the development and analysis of the BJ-AM ceramic processes. Understanding BJ-AM process principles and ceramics processing challenges requires reviewing a number of fundamental principles, which this article delineates. The discussion covers the processability considerations, a brief summary of some fundamental aspects of modeling of liquid permeation in the powder bed, and process capabilities and advantages of BJ-AM technology.

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.

This article provides an overview of metal additive manufacturing (AM) processes and describes sources of failures in metal AM parts. It focuses on metal AM product failures and potential solutions related to design considerations, metallurgical characteristics, production considerations, and quality assurance. The emphasis is on the design and metallurgical aspects for the two main types of metal AM processes: powder-bed fusion (PBF) and directed-energy deposition (DED). The article also describes the processes involved in binder jet sintering, provides information on the design and fabrication sources of failure, addresses the key factors in production and quality control, and explains failure analysis of AM parts.

This article provides a brief overview of additive manufacturing (AM) of tool steels via various AM technologies such as laser powder bed fusion, electron powder bed fusion, blown powder directed energy deposition, and binder jet AM. The discussion includes process overview and covers the mechanism, advantages, and applications of each of these techniques.

This article is a detailed account of additive manufacturing (AM) processes for copper and copper alloys such as copper-chromium alloys, GRCop, oxide-dispersion-strengthened copper, copper-nickel alloys, copper-tin alloys, copper-zinc alloys, and copper-base shape memory alloys. The AM processes include binder jetting, ultrasonic additive manufacturing, directed-energy deposition, laser powder-bed fusion, and electron beam powder-bed fusion. The article presents a review of the literature and state of the art for copper alloy AM and features data on AM processes and industrial practices, copper alloys used, selected applications, material properties, and where applicable, compares these data and properties to traditionally processed materials. The data presented and the surrounding discussion focus on bulk metallurgical processing of copper components. The discussion covers the composition and performance criteria for copper alloys that have been reported for AM and discusses key differences in process-structure-property relationships compared to conventionally processed material. The article also provides information on feedstock considerations for copper powder handling.

Tungsten, molybdenum, and cemented carbide parts can be produced using several additive manufacturing technologies. This article classifies the most relevant technologies into two groups based on the raw materials used: powder-bed methods, such as selective laser melting, electron beam melting, and binder jet three-dimensional (3-D) printing, and feedstock methods, such as fused-filament fabrication and thermoplastic 3-D printing. It discusses the characteristics, processing steps, properties, advantages, limitations, and applications of these technologies.

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.

This article covers the current state of materials development of nickel-base superalloys for additive manufacturing (AM) processes and the associated challenges. The discussion focuses on nickel-base superalloy fusion AM processes, providing information on typically encountered cracking mechanisms in AM nickel-base superalloys, such as solid-solution-strengthened nickel-base superalloys and precipitate-strengthened nickel-base superalloys. The mechanisms include solidification cracking, strain-age cracking, liquation cracking, and ductility-dip cracking. The article also provides a short discussion on binder jet AM and powder recyclability.

This article describes post-processing techniques for machining, finishing, heat treating, and deburring used to remove additive manufacturing (AM) metallic workpieces from a base plate and subsequent techniques to enhance printed workpieces. The AM processes include powder bed fusion, binder jetting, and direct energy deposition. The discussion provides information on powder removal, powder recycling and conditioning, part removal, and part enhancement. The mechanism, applications, advantages, and limitations of mechanical, radiation, and chemical-finishing processes as well as the properties of the resulting material are also covered.

Traditional processing methods for the part production of Co-Cr alloys include casting, powder metallurgy, and metal forming. However, the steps involved during materials processing followed by metal forming and machining are time consuming and fraught with processing variables. Three-dimensional (3D) printing enables rapid evolution in design, personalization, and so on. This article presents a brief description of some common additive manufacturing (AM) processes for the production of cobalt alloy parts, and provides a comparison between AM and conventional processing methods. The discussion is centered on process-microstructure-properties correlation in additively manufactured cobalt alloys and applications of these alloys.

This article presents a brief history of additive manufacturing (AM). It begins by describing additive manufacturing prehistory, dating back to 1860, which is characterized by additive part creation without the use of a computer. The article then discusses the development of additive manufacturing processes occurring in the period from 1968 to 1984 and is followed by a section on modern additive manufacturing (1981 to the late 2000s). The article concludes by providing information on the growth of additive manufacturing since 2010 and the development of standards.

This article discusses the advantages, limitations, and applications of material jetting of ceramics, focusing on two primary methods of droplet formation: continuous stream and drop on demand (thermal and piezoelectric) ink jetting processes.

This article presents a detailed account of the processes involved in vat-photopolymerization-based fabrication of ceramics, namely bioceramics, structural ceramics, piezoelectric ceramics, optical ceramics, and polymer-derived ceramics. Information and methods of material preparation, curing characteristics, green-part fabrication, property identification, process design and planning, and quality control and optimization are introduced. The article also provides information on postprocessing techniques, namely debinding and sintering, as well as on the phenomenon of shrinkage and compensation.

This article focuses on various vacuum heat treating processes for additively manufactured parts, namely annealing and stress relieving, solid-solution annealing, and solution treating and aging. It addresses several practical concerns involved in using vacuum heat treatment, including temperature measurement, unvented cavities, loose powder, and direct contact of metals in the high-temperature vacuum. The article provides a short discussion on sintering and evaporation of metals in vacuum furnaces.

Hot isostatic pressing (HIP) is widely used within the additive manufacturing (AM) industry to improve material performance and ensure quality. This article is a detailed account of the HIP process, providing information on its equipment set up and discussing the applications, economics, and advantages of the process. The discussion also covers the use of HIP for additively manufactured material to eliminate internal defects, the HIP parameters required to eliminate internal defects, and the influence of HIP on the microstructure and properties of HIP additively manufactured material.

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.

Sand casting processes are typically classified according to the type of binder present in the molding sand mixture. This article discusses common sand casting processes and design considerations related to shape, gating, feeding, and pattern making methods. It describes the composition of sand and binder normally used, and provides information on the aluminum casting alloys produced. The article discusses precision sand casting and sand reclamation, and includes information on health and safety considerations.

Aluminum powders can be formed into components by several competing technologies, including powder metallurgy (PM), metal injection molding, powder forging, and additive manufacturing. This article explores PM methodologies that are being exploited to manufacture such components. It reviews emerging technologies that promise to offer exciting ways to produce aluminum parts. The article discusses the various steps involved in PM, such as powder production, compaction, sintering, repressing, and heat treatment. It provides information on aluminum production statistics and the wear-resistance applications of PM.