A PERSPECTIVE ON METAL ADDITIVE MANUFACTURING AND EMERGENCE OF BINDER-BASED POWDER PROCESSES

Additive manufacturing (AM) also known as 3D printing has been gaining increasing attention in the manufacturing community and has been attracting unprecedented financial investment, rarely observed in the manufacturing technology domain. The lure of AM stems from some of the unique advantages that this technology has to offer. The process is additive in nature and allows designers the ultimate freedom. The major advantage is that AM does not rely on any physical tooling (or die) something required by most other material-shaping technologies. Though the various AM technologies are often widely different in the way they fabricate the complex 3D structures (use lasers, electron beams, rely on jetting of binders on a powder bed, extruding and laying down filaments of metal-organic binder, etc.), almost all the AM technologies have a few things in common. They all fabricate net- or near-net-shaped 3D components directly by importing 3D computer-aided design (CAD) data files digitally and then forming the part layer-by-layer based on the sliced model generated from the CAD data. This paper will provide a brief historical perspective on the general AM technology area. This perspective will include the naming of the different 3D forming processes, growth of the overall AM sector, and comment on the possible impact of AM on the demands for metal powders. The paper will briefly discuss the recent emergence of two metal AM processes (binder jetting and material extrusion) that use powder and organic binders for shaping parts followed by sintering for consolidating the final parts, and a general comparison with the metal injection molding (MIM) process. © 2019, American Powder Metallurgy Institute. All rights reserved.