Selective laser melting of aluminium metal-matrix composites and the challenges

Abstract

Metal matrix composites based on aluminium metal matrices offer material solutions for high performance and low weight applications. The reinforcement filler materials in the form of continuous or discontinuous fibres, whiskers or particulates allow for the properties to be tailored to suit to different application demands. Several grades of aluminium matrix composites manufactured by different means are currently in use for high-tech structural and functional applications including aerospace, defence, automotive, and thermal management areas, as well as in sport’s needs. The growth in the additive manufacturing technologies made possible a plethora of new opportunities in terms of controlling the dispersion of the filler particles, which is in particular a major constraint with the traditional bulk manufacturing methods. While there are specific benefits drawn from the point-by-point consolidation mechanics of additive processes such as selective laser melting, certain drawbacks are also hindering the widespread application in aluminium metal matrix composite processing. Practical difficulties associated with the presence of continuous or discontinuous fibres, whiskers and other particulates and the unique microstructures resulting from the typical material consolidation mechanics are specific examples. The state-of-the art of applying selective laser melting to process aluminium metal matrix composites will be reviewed in the current paper, with specific emphasis paid to in-situ arrangement of the fillers and the material, process, structure, and property relationships.