An experimental study on single-point diamond turning of a 55 vol% SiCp/Al composite below the ductile brittle transition depth of SiC

Abstract

To achieve excellent surface quality, this paper presented an experimental study on single-point diamond turning of a 55 vol% SiCp/Al composite below the ductile brittle transition depth of SiC. The dry and mist cutting results indicated that the surface roughness generated by dry turning is much higher than those generated by mist turning. Surface roughness decreased with the increasing rotation speed and increased with the increasing feed rate, while the influence of depth of cut was insignificant. The minimum surface roughness S_a could be achieved around 0.05 μm. Besides, the roughness rebounded obviously under much small feed rate (0.5 μm/z) or depth of cut (0.25 μm). Machined surface examined by SEM indicated that many SiC particles were cut in ductile mode, while there were still numerous defects, such as holes, pits, tearings, grooves, and voids. The chipping, cleavage, and abrasive wear were the dominating wear patterns of diamond tools. In the end, the main influential factors on the cutting process of SiC and approaches for enhancing the probability of ductile cutting SiC were discussed.