Sub-surface sinking effect of reinforcement particle in laser assisted machining of metal matrix composites

Abstract

Aluminium-based SiC particle-reinforced metal matrix composites are widely used in engineering applications due to their exceptional mechanical properties. However, their machining remains challenging due to the mismatch of material properties between the brittle SiC particles and the ductile aluminium matrix, causing tool wear and surface damage. To mitigate these issues, laser inverse problem scanning is utilised to strategically melt the top layer aluminium matrix, allowing the SiC particles to sink and promoting more ductile Al-matrix. The strategic hybrid laser milling approach optimises particle sinking, reduces tool wear and enhances surface integrity by minimising particle fracture, pullout and refining microstructure.