抄録
Machinable ceramics consisting of fluor-phlogopite can be easily machined using conventional metal working equipment and tools. In recent years, ceramic parts require precise machining. The formation of cracks has a direct effect upon the machined surface.
The purpose of this paper is to study the mechanism of crack propagation in machinable ceramics. The investigation of the behavior of cracks in ceramics was carried out using a simple model of the finite element method (FEM).
The main results obtained are as follows: (1) The pattern of crack propagation are type (A) of straight path in the mica and type (B) of detour path to boundary glass and mica. (2) The deflection and the branching of the crack are most influenced with the ratio of the maximum fracture stress of the mica to that of the glass. (3) Assuming that the propagation length of crack is proportional to the fracture energy, this energy of crack type B to type A increases to about 60% with the ratio of propagation length at 1.66 times.
