Metal 3D printing — more precisely, metal additive manufacturing — builds a solid metal component directly from a 3D model, layer by layer, without tooling. In industrial processes the material starts as a fine, spherical metal powder and is fused into fully dense metal using a laser or, in binder-based routes, bound and then sintered.
How the process works
A CAD model is prepared for build: oriented, supported where required and sliced into layers typically between 20 and 60 microns thick. A recoater spreads a layer of powder across the build plate, the laser melts the cross-section of the part into the layer below, the plate lowers, and the cycle repeats — often tens of thousands of times for a single component.
What comes off the machine is not a finished part. The build plate carries the components, their support structures and residual powder. Stress relief, part removal, support removal, machining of critical features, surface finishing and dimensional inspection all follow.
The main industrial processes
- Laser Powder Bed Fusion (L-PBF) — a laser fully melts metal powder. The most widely used route for precision engineering components.
- Direct Metal Laser Sintering (DMLS) — commercially the same family as L-PBF, and the term most often used for complex, lightweight, low-volume metal parts.
- Binder Jetting — a binder is printed into the powder bed and the green part is then debound and sintered, which suits higher volumes.
What it is good at
- Geometry that cannot be machined — internal channels, thin organic structures, lattices.
- Consolidating an assembly into a single component.
- Low volumes and prototypes where tooling cost cannot be justified.
- Difficult materials such as titanium and nickel superalloys where machining from solid wastes expensive stock.
What it is not
Additive manufacturing is not a cheaper substitute for machining a simple prismatic part, and it does not remove the need for machining altogether. Tight tolerances, sealing faces, bearing bores and threads are still produced by conventional means, on the printed component.