Surface generation mechanism of WC/Co and RB-SiC/Si composites under high spindle speed grinding (HSSG)

The surface generation mechanisms of WC/Co and Reaction-bonded SiC/Si (RB-SiC/Si) composites under high spindle speed grinding (HSSG) were investigated in the present work, compared with quasi-static indentation test The results showed that surface generation mechanism for WC/Co and RB-SiC/Si varied under both quasi static indentation and dynamic grinding. Only plastic deformation occurred for WC/Co indicating its higher toughness, while pop-out effect induced by phase transformation in RB-SiC/Si would prompt the chipping at phase boundaries under indentation. Under dynamic grinding, WC/Co underwent plastic deformation, grain dislodgement and WC particles crush, while ductile removal, phase boundaries crack (along the grinding direction) and chipping fracture occurred for RB-SiC/Si with the increase of cutting depth. It was found that the binder in the bulk WC/Co and RB-SiC/Si played a decisive role on the material removal mode, and the mechanics of grain dislodgement for WC/Co and RB-SiC/Si were analyzed based on a geometrical model. Besides, three types of grinding wheel wear appeared, including grit dislodgement, flattening and splintering, which bear an obvious influence on the surface generation. (C) 2016 Elsevier Ltd. All rights reserved.