Splitting Opaque, Brittle Materials with Dual-Sided Thermal Stress Using Thermal-Controlled Fracture Method by Microwave

Abstract

The thermal-controlled fracture method has been increasingly focused upon in the high-quality splitting of advanced brittle materials due to its excellent characteristics related to the fact that it does not remove material. For opaque, brittle materials, their poor fracture quality and low machining capacity resulting from their single-sided heat mode is a bottleneck problem at present. This work proposed the use of dual-sided thermal stress induced by microwave to split opaque, brittle materials. The experimental results indicate that the machining capacity of this method is more than twice that of the single-sided heat mode, and the fracture quality in splitting opaque, brittle materials was significantly improved by dual-sided thermal stress. A microwave cutting experiment was carried out to investigate the distribution characteristic of fracture quality by using different workpiece thicknesses and processing parameters. A dual-sided thermal stress cutting model was established to calculate the temperature field and thermal stress field and was used to simulate the crack propagation behaviors. The accuracy of the simulation model was verified using temperature measurement experiments. The improvement mechanism of the machining capacity and fracture quality of this method was revealed using the fracture mechanics theory based on calculation results from a simulation. This study provides an innovative and feasible method for cutting opaque, brittle materials with promising fracture quality and machining capacity for industrial application.