Laser Based Machining of Aluminum Metal Matrix Composites

Abstract

Aluminium metal matrix composites (Al MMC) are a relatively new type of material which combine lightweight metallic matrices (aluminium) with hard ceramic reinforcements (like alumina fibre or silicon carbide particles). Al MMCs have excellent potential in various applications from automotive to aerospace; however, their use is currently limited due to their low machinability. Conventional laser processes such as the laser drilling or cutting of monolithic materials (metals/alloys) are well-established processes. However, conventional laser processing of anisotropic materials like metal matrix composites is challenging due to the immense differences in the chemical and physical properties of the matrix and reinforcement. Over the last decade, nanosecond laser based water jet guided (WJG) machining has securely established itself as a novel laser based machining process, especially for the machining of non-monolithic materials like composites. The main investigation of this paper is centred on understanding the performance of WJG laser and conventional high power fibre laser machining of Al MMC. Laser machining of both fibre-based and particle-based Al MMC has been investigated (Al2O3 Fibre–Al MMC; SiC Particle–Al MMC). The WJG laser machining results were compared with the results from conventional long pulse/continuous wave laser process.