Investigation on the machinability of SiCp/Al composite by in-situ laser assisted diamond cutting

As a difficult-to-cut material, high-quality machining of SiCp/Al composite is a huge challenge for conventional machining techniques. In this study, an in-situ laser assisted diamond cutting technology was innovatively applied to SiCp/Al composite machining. The influence of machining parameters on machined surface roughness and morphology was analyzed. The wear mechanism of the diamond tools with conventional and in-situ laser assisted diamond cutting was revealed. Subsurface damage was investigated from residual stress and crystal defects. Experimental results show that the in-situ laser assisted diamond cutting technology effectively inhibits the generation of large-sized surface defects such as scratches and pits, and improves surface quality. Compared with conventional diamond cutting, the best surface roughness Sa is significantly decreasing by 89.5% to 10.2 nm. In addition, residual stress is effectively reduced by 42%. In in-situ laser assisted diamond cutting, the main tool wear form is flank wear caused by abrasive wear and chemical wear. During processing, an amorphous layer of about 40 nm is generated on the machined surface, accompanying subsurface defects such as particle fracture, micro-crack, dislocations, and stacking faults. The in-situ laser assisted diamond cutting is an effective and promising method for ultra-precision machining SiCp/Al composites.