A further study of wheel normal grinding of hemisphere couples on TiC-based cermet

Ultra-precision grinding of hemisphere couples on TiC-based cermet was conducted in the present work to achieve optical quality surface. Wheel normal grinding was utilized to avoid the interference between the machined surface and diamond wheel. Sharp grinding edge of the wheel was firstly prepared with a green silicon carbide (GC) stick as truer. The results showed that surface finish of the machined hemispherical couples was improved with Ra = 9 nm by a 100 % 2000# diamond wheel, compared with the surface roughness Ra = 13 nm machined by 75 % 2000# diamond wheel. Furthermore, compensation of the wheel wear was performed to reduce the radius deviation, and the finally achieved radius of a convex surface was 7.5016 mm. In addition, varied surface damage (hard particle dislodgement, micro-cracks, and grinding grooves) was induced during grinding, even under much finer machining parameters (feed rate: 0.1 mm/min, grinding depth: 0.1 μm).