Recently, ultrashort pulse laser processing has been attracting attention as a method for microprocessing SiC. However, there is a severe problem with this technique: cracks formed around the processed shape hinder precision processing. In this study, to reveal the mechanism of crack formation during the ultrashort pulse laser processing of SiC, we investigated the high-speed phenomena happening during processing. The phenomena were captured using an imaging system consisting of the pump-probe imaging method and a high-speed camera. The ultrashort pulse laser and the high-speed camera are operated at 1 kHz in synchronization, which enables us to capture the high-speed phenomena during processing that change as the process progresses. As a result, we have succeeded in capturing the damage formation process. The results show that the damage is generated and grows only near the tip of the processed hole and does not change once it is generated. As known from previous studies, stress waves propagate around the tip of the processed hole during machining, suggesting a strong correlation between stress waves and damage generation. The larger the pulse energy, the more damage is generated, due to the large stress waves generated because of the large removal volume. When the pulse width is long, the material is thermally affected, and thermal damage is thought to occur at the entrance of the processed hole.
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