Consolidation behaviour and microstructure characteristics of pure aluminium and alloy powders following Selective Laser Melting processing

Abstract

Selective Laser Melting (SLM) is an additive manufacturing process that directly consolidates metal powders to form near net shape or net shape components. A few commercial SLM systems have started to process a select choice of aluminium alloys. These alloys are generally based on conventional casting alloys that do not represent the highest performance aluminium alloys for aerospace application. This paper studies the consolidation behaviour and resulting microstructure of pure aluminium, 6061 alloy powder and a mixture of 6061 alloy powder with copper powder under different SLM processing parameters. It has found that the addition of copper powder to 6061 Al powder considerably changes the consolidation behaviour and the microstructure evolution, resulting in a denser and much finer microstructure. This work therefore demonstrates the premise to develop specific aluminium alloy powders for the SLM process and enabling the fabrication of high performance aluminium based products.