Study of the formation and propagation conditions of grinding crack for ceramics

Based on the behaviour of grinding stresses field of ceramics, and indentation fracture mechanics, micro-fracture physics and Finite element method, the formation mechanism of micro-crack and its effect factors in the process of grinding are studied. The distribution model of crack is proposed. According to the mechanism that micro-cracks come into being from the dislocation, the dislocation piled-up model is employed to describe the grinding crack, Following the principle of equilibrium of energy, the relations of the length of dislocation crack and critical grinding stresses are discussed, and the critical condition of realizing ductile/brittle transform is confirmed.