A novel method by microwave cutting ceramics based on thermal crack and trajectory control

Herein, the microwave thermal crack method is innovatively employed in cutting Al₂O₃ ceramics. Different from the conventional cutting technology, the thermal controlled fracture method is progressive and environmentally friendly, which adopts tensile stress to peel off the brittle material into two parts. The heat source induces tensile stress as thermal stress. Additionally, based on the Fourier heat transfer equation and thermo-elasticity, the physical model of microwave thermal crack cutting Al₂O₃ ceramics is established and calculated. The thickness of the graphite coating, the width of the graphite coating, and the prefabricated crack in the process of microwave thermal crack cutting Al₂O₃ were studied. The effect of graphite coating width on crack trajectory was also investigated by simulation combined with the test. From the result, it can be seen that the narrower the width of graphite coating, the weaker the processing ability and the better the trajectory control ability. The microscope is adopted to evaluate the surface and cross-section morphologies detailly. This study elaborates briefly on the interaction mechanism of microwave thermal crack cutting Al₂O₃ ceramic surface and provides practical guidance for aerospace industries applications.