Strain rate-sensitive analysis for grinding damage of brittle materials

Abstract

Grinding of brittle materials will inevitably cause grinding damages characterized by fracture microcracks, which will greatly affect the grinding integrity. Traditional damage models are just concerned about the material properties and interaction depth between grit and workpiece without considering the dynamic effect on material strength. This paper proposed new damage analysis models which consider the effect of both strain rate and grinding parameters on grinding damages. It is believed that the material strength and dynamic fracture toughness vary under different grinding parameters due to the variation of strain rate brought by the grinding speed and chip thickness. By introducing the grinding-induced strain rate, the new damage models were further updated as the function of the grinding speed and chip thickness. The grinding damage models were verified through different grinding tests. Combining with the surface roughness results, the grinding damages under different grinding speed and damages are fully discussed. Finally, the damage-free grinding was proposed based on the proposed model. It can be concluded that a combination of the grinding speed and reduction of the chip thickness can help achieve damage-free ground surface.