High-precision low-damage grinding of polycrystalline SIC

Spherical grinding was conducted with a ductile regime mode using a CNC grinding machine and a metal-bond diamond tool with a grit size of 25 mum. The ductile grinding process generated silicon carbide spherical surfaces with surface roughness of <10 nm Ra, evaluated by an optical profiler and an atomic force microscope. Using a scanning electron microscope, the ground silicon carbide exhibited little visible grinding-induced cracks except for some residual porosity associated with the fabrication process of the polycrystal. The x-ray diffraction tests indicated that no phase transformation in silicon carbide occurred during the grinding process.