Selective laser melting of aluminium and aluminium metal matrix composites: review

Selective laser melting (SLM) is gaining importance as companies begin to exploit its advantages to produce parts that will enable them to enter the market sooner, at a lower cost and/or with parts having an increased geometric complexity. Since aluminium is the second most popular engineering material after steel, its use in SLM was inevitable. In this review, we look at the SLM of aluminium and aluminium matrix composites. We explore some of the inherent difficulties in working with aluminium including the presence of a stable oxide layer, high reflectivity and thermal conductivity and poor flowability of the powder. We also review the unique microstructures that are produced during the SLM process and its effect on the mechanical properties. Included in this is the effect of heat treatment on the structure and properties. Finally, we look at the benefits and problems of producing aluminium metal matrix composites using SLM.