3D printing is so much the rage now that the additive manufacturing process is almost a standard for many industries' metal parts creation.
In the interest of becoming educated on the topic, here's a brief roundup of the 3D printing distinctions out there:
Sintering
One of the earliest 3D printing innovations, direct metal laser sintering was a game-changer. Here, a high-energy printer laser sinters aluminum or titanium powders to precise design. The metal powders need to be very granular, and every printing layer must have exactly the same, to-the-micron height.
Selective laser melting
Like sintering, selective laser melting (SLM) is a technique that forms 3D objects with a high-powered laser beam that fuses metallic powders (like stainless steel, cobalt chrome, and aluminum). But unlike sintering, the SLM process fully melts the metal material into solid 3D parts, 2D layer by 2D layer. End products with intricate internal geometries are good fits for SLM.
Electronic Beam Melting
This 3D printing method is also a powder-bed-fusion technique, but instead of using a high-powered laser beam as its power source, EBM uses an electron beam. Otherwise, EBM is pretty identical to SLM.
Jet Binding/Binder Jetting
Jet binding, or binder jetting, is one of the newer additive approaches—a standout for requiring less equipment investment and being faster and safer than sintering. Here, a liquid resin binder is selectively deposited on metal powder particles by an ink-jet-printer-style print head until it's formed a predetermined shape. Binder jetting is unique for not employing heat during the build process.
Arc Energy Printing
This approach uses a rod or wire's electric arc energy to deposit metal in a back-and-forth pattern to produce big parts. Arc energy printing is celebrated for being safe (it relies on a welding-style wire as the base material instead of volatile powder) and for producing very strong—if somewhat coarse—parts.
As additive approaches mature and become more refined, and research into metal powders increases, the scope of 3D printing options will grow exponentially. And the number of commercial applications that come to rely upon them will do likewise.