What is selective laser melting (SLM)?

Selective laser melting is one of the laser powder bed fusion technologies. Selective laser melting (SLM) is one of many proprietary names for a metal additive manufacturing (AM) technology that uses a bed of powder with a source of heat to create metal parts. Also known as direct metal laser sintering (DMLS), the ASTM standard term is powder bed fusion (PBF). PBF is a rapid prototyping, 3D printing, or additive manufacturing technique designed to use a high power-density laser to melt and fuse metallic powders together.

How does selective laser melting work?

Like any other 3D printing process, SLM metal 3D printers need a CAD file as a blueprint for the desired part. The data set is cut into a number of layers by a slicer. Each layer forms a cross-section through the component. A layer thickness in 3D printing SLM usually varies between 20 and 60 micrometers. In the SLM 3D printing process, a squeegee spreads a layer of metal powder onto a lowerable build platform. A laser then scans the cross-section of the part and melts the powder in those areas. Because the powder cannot be compressed as densely as in SLS, the process relies on printed support structures in most cases. They serve to keep the components stable in the build space, to dissipate excess heat and to prevent deformation of the parts.

What materials are used in selective laser melting?

Selective laser melting is used to process metals. The development of new materials is a continuously advancing field of research, and new suppliers or established companies are constantly entering the market with a greater variety of materials. The most established materials for SLM 3D printing include aluminum (AlSi10Mg), tool and stainless steel (1.2709 & 1.4404) and titanium (Ti6Al4V).

What can selective laser melting be used for?

Many industries benefit from selective laser melting as an additive manufacturing technology. These include aerospace, automotive engineering, dental and medical technology, and mechanical engineering. The technology is used in particular for rapid prototyping, but small series can now also be economically produced using SLM metal 3D printing.