Improving Productivity Rate in SLM of Commercial Steel Powders

Selective laser melting (SLM) is a powder-based additive manufacturing process capable to generate 3D parts from a CAD model. The competitive advantages of SLM are geometrical freedom, shortened design to product time, mass customization and material flexibility. Recent technical improvements have made a shift of the process applications from rapid prototyping to rapid manufacturing. Currently there is a growing interest in industry for applying this technology for generating high geometrical complexity and low quantity parts, among them are medical parts and tooling inserts. To turn the SLM process into a production technique for real components, some conditions have to be fulfilled. Productivity is one of those conditions that plays a key role for further applications of this process and that is discussed in this paper. However, compared to selective laser sintering (SLS), the productivity rate is lower because SLM is carried out at scanning speeds much slower than the speed range normally used in SLS. This study attempts to improve the SLM parts productivity rate for commercial steel powders, 316L stainless steel and DIN 1.2709 maraging steel. The influences of processing parameters on the parts' relative density as well as surface quality are investigated. A wide range of scanning speed, scan spacing and layer thickness as well as part shape's effect are considered. The effect of particle size on the results is also investigated.status: publishe