Selective laser melting of metallic powder bed

The standard NF EN ISO/ASTM 52900 defines additive manufacturing as the set of processes involving the assembly of materials to produce parts based on 3D model data, typically layer by layer, as opposed to subtractive and form-making manufacturing methods.

Metal additive manufacturing processes can be divided into two broad categories defined by how the printed part is consolidated:

• direct processes involving melting: require a single consolidation step (e.g., powder bed fusion –, PBF; directed energy deposition –, DED). These technologies generally have a level of maturity that allows for a comprehensive understanding of the value chain;

• indirect processes without melting: require multiple consolidation steps (e.g., 3D sand printing + foundry casting, Metal Binder Jetting – MBJ/stereolithography/wire deposition/material jetting + sintering + solid metal layer + brazing/diffusion welding). Technologies based on metal-binder mixtures have reached increasing industrial maturity in recent years.

Advances in additive manufacturing processes naturally lead to the emergence of new manufacturing solutions that overcome certain technological barriers, such as increasing productivity, improving part surface finishes, reducing geometric constraints, and minimizing the amount of support material required for the production of complex shapes.

This article on powder bed fusion with a laser beam (PBF-LB – Powder Bed Fusion-Laser Beam) covers the production process from powder characterization through design and manufacturing to thermal post-processing and finishing—all of which are necessary to ensure a high level of quality.