Direct laser metal deposition of eutectic Al-Si alloy for automotive applications

Abstract

Various additive manufacturing techniques have been able to manufacture Al-Si hypo- and hyper-eutectic alloys but practical implementation of additive manufacturing of Al-Si alloys in automotive industry still remains a big challenge. This paper deals with the challenges of building tall wall and cuboid shapes eutectic Al-Si components by direct laser metal deposition technique for automotive applications. Microstructural investigation using optical and scanning electron microscopy revealed a 99.9% dense component with very fine hypoeutectic microstructure. Tensile test showed an impressive elongation of 9% with an ultimate tensile strength of 225 MPa. This investigation revealed that direct laser metal deposition could be successfully implemented on automotive shock tower hood without any distortion or bending. This paper also presents the effect of various laser deposition parameters like laser power, powder flow rate, and scanning speed on the microstructure and mechanical properties distribution from substrate to deposit.