Effects of binder concentration on the nanometric surface characteristics of WC-Co materials in ultra-precision grinding. (December 2019) - Zhang, Quanli
Abstract: The influence of the binder concentration on the nanometric surface characteristics of WC/Co in ultra-precision grinding is investigated in the present work. The results firstly show that the surface finish of the ground WC/Co changed with increasing Co content, and the machined surfaces were covered by many micro-pits and surface burs induced by the plastic deformation and the prior removal of Co binder, which also led to the micro-chipping of the WC grains near the boundaries for the lack of support by Co. Many finer scratching grooves in the feed marks appeared, but the periodic grinding grooves caused by the feed of the diamond wheel became unclear with increasing Co content and the vibration induced marks on the machined surface turned to be primary, the spatial frequency of which is identified to be around 130 1/mm by the Fast Fourier transform. In addition, for the isotropic of the statistical size of the WC grains and the thickness of Co binder along each direction, a circular symmetry shape of the spatial frequency forms and the radius increases with increasing Co content. Highlights: The extra material removal of Co results in the edge chipping of the WC grains under the scratching of the diamond grits. The size of the randomly distributed micro-pits formed due to the prior removal of Co grows with increasing Co content. The periodic vibration marks on the machined surface turn to be irregular with increasing Co concentration.