Effect of process parameters on the surface characteristics of AlSi12 samples made via Selective Laser Melting

Abstract

In the past decade there has been a rapid growth in additive manufacturing and its applications in a wide range of industries. Selective laser melting (SLM) is one such technology, which uses a powder-bed system to selectively sinter/melt the powdered material resulting in a dense structure. However, an optimized set of process parameters have to be established for each material system to maximizethe performance of the components built in the SLM machine. In this research work, several experimental trials were carried out to investigate the influence of the laser power and defocus distance of the laser beam on the surface quality of the parts fabricated using AlSi12 alloy powders. The as-built samples were characterised using 3D profilometry, scanning electron microscopy, and microhardness testing. From the results obtained, it was concluded that a defocus distance of -3 mm at a laser power of 95% were the best combination of laser parameters to achieve good surface finish on the as-built AlSi12 parts on SLM.