A metal 3D printer builds fully-dense metal parts layer by layer from a digital CAD file. Depending on the technology DMLS, DED, or BMD it either sinters metal powder with a laser, melts metal wire as it is deposited, or extrudes metal-filled rods for later sintering. All processes produce parts with mechanical properties comparable to conventional metalworking, enabling complex geometries impossible to machine or cast.

The most common materials include stainless steel (316L, 17-4 PH), titanium (Ti6Al4V), aluminium (AlSi10Mg), tool steel (H13, M300, A2, D2), Inconel 625/718, cobalt chrome, copper, and maraging steel. Material availability depends on the process — DMLS supports the broadest range, DED wire uses standard welding wire feedstock (far cheaper than powder), and BMD offers metal-specific rods for stainless, tool steel, and copper. Phillips can advise on the optimal material-process combination for your application.

DMLS (Direct Metal Laser Sintering) and SLM (Selective Laser Melting) are both laser powder-bed fusion processes. DMLS, pioneered by EOS, operates at temperatures below the melting point to achieve sintering, while SLM fully melts the powder. In practice, modern DMLS systems including EOS achieve near-complete melting and densities above 99.5% making the distinction largely academic. The terms are often used interchangeably in industry. More meaningful differentiators are the number of lasers, build volume, inert atmosphere quality, and material parameter libraries offered by each OEM.

Most metal 3D printed parts require:

1. stress relief heat treatment in an inert atmosphere furnace to remove residual stresses.

2. Support structure removal by machining, grinding, or wire EDM

3. Surface finishing bead blasting to Ra 4–6 µm as standard, or CNC machining/polishing for tighter tolerances.

Some structural aerospace applications require Hot Isostatic Pressing (HIP) to close any residual micro-porosity.