1. Scope

Keywords

Rationale

5.1 A broad classification of AM systems based on the initial form of feedstock material (material with which the part is built) is: 5.1.1 Powder-Based AM SystemsMetals, polymers, and ceramics: 5.1.1.1 Selective laser melting (SLM) (metals); 5.1.1.2 Electron beam melting (EBM) (metals); 5.1.1.3 Directed energy deposition (metals): (1) Laser engineered net shaping (LENS) and (2) Rapid plasma deposition (RPD); 5.1.1.4 Selective laser sintering (SLS) (polymers); 5.1.1.5 Multi-jet fusion technology (polymers); and 5.1.1.6 Binder jetting (ceramics). 5.1.2 Liquid-Based (Vat Polymerization) AM SystemsResins and photopolymers: 5.1.2.1 Stereo lithography apparatus (SLA) (photopolymers), 5.1.2.2 Direct light processing (DLP) (photopolymers), and 5.1.2.3 Continuous liquid interface production (CLIP) (photopolymers). 5.1.3 Solid-Based AM SystemsWires, laminates, and pellets: 5.1.3.1 Fused deposition modeling (FDM) (polymers-wire), 5.1.3.2 Electron beam wire feed (EBAM) (metals-wire), 5.1.3.3 Laminated object manufacturing (LOM) (laminates-paper and plastics), and 5.1.3.4 Ultrasonic consolidation (UC) (metals). 5.2 AM facilities that use powder bed fusion (PBF) process to create parts make use of metal powders (in SLM) and polymer powders (in SLS) as feedstock material. 5.3 A variety of metals and alloys including aluminum, cobalt, nickel, stainless steel, and titanium are used in the SLM process. The building process generally takes place in an inert atmosphere using gases such as nitrogen, argon, and so forth. Nitrogen is typically used for stainless steel, nickel alloys, and cobalt chrome. Argon is used when fabricating parts using aluminum and titanium powders. The AM system, raw powder, filter system, and ancillary AM equipment (for example, wet separator vacuum) all pose safety and environmental hazards that shall be covered by this guide. 5.4 The SLS process uses various polymer powders such as polyamide 12 (Nylon12), polyamide 11, polyamide 12 with aluminum/carbon fiber/glass bead, polyether ether ketone (PEEK), thermoplastic poly urethane (TPU), thermoplastic elastomer (TPE), polycarbonate, polyether block amide (PEBA), and so forth to produce plastic parts. 5.5 The binder jet process uses a number of ceramic powders (in addition to metal powders) for printing of parts. Commonly used ceramic materials include, but are not limited to, aluminum oxide, calcium sulfate, silica, ceramic sand, gypsum, and glass.