Abstract Silicon carbide (SiC) ceramics, due to their excellent mechanical properties and oxidation resistance at elevated temperature, have a widespread application in microelectronics and aerospace. However, the machining of SiC ceramics into the desired structural ceramic components presents a challenge because of their high hardness and high brittleness. In this paper, a novel method of underwater femtosecond laser polishing SiC ceramics was proposed. We investigated the influence of scan trajectory, such as scanning pitch and polishing mode, and femtosecond laser pulse energy on surface roughness and polishing depth during underwater polishing processing. The experimental results indicated that the polishing depth decreased with the increasing scanning pitch, and then tending to saturate. A deep cavity was obtained under the condition of high laser pulse energy and small scanning pitch during polishing. However, the obtained surface quality was rough at this condition, which could be used for rough polishing operation because the high material removal rate is the primary concern. In addition, the cross-scanning polishing mode achieved the better surface quality without cracks and pits than the transverse polishing mode, but the polishing efficiency was low. In addition, under appropriate machining conditions, the smooth polished surface with surface roughness 0.76 µm was obtained by using 15 µm scanning pitch together with high laser pulse energy and cross-scanning polishing mode.

中文翻译：

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水下飞秒激光抛光碳化硅陶瓷扫描轨迹的实验研究

摘要 碳化硅（SiC）陶瓷由于具有优异的机械性能和高温抗氧化性能，在微电子和航空航天领域有着广泛的应用。然而，由于碳化硅陶瓷的高硬度和高脆性，将其加工成所需的结构陶瓷部件是一个挑战。本文提出了一种水下飞秒激光抛光SiC陶瓷的新方法。我们研究了扫描轨迹，如扫描间距和抛光模式，以及飞秒激光脉冲能量对水下抛光加工过程中表面粗糙度和抛光深度的影响。实验结果表明，抛光深度随着扫描间距的增加而减小，然后趋于饱和。抛光时在高激光脉冲能量和小扫描间距的条件下获得深腔。然而，在这种条件下获得的表面质量很粗糙，可以用于粗抛光操作，因为高材料去除率是主要问题。此外，交叉扫描抛光方式比横向抛光方式获得了更好的无裂纹和凹坑的表面质量，但抛光效率较低。此外，在适当的加工条件下，采用15 µm的扫描间距，结合高激光脉冲能量和交叉扫描抛光方式，获得了表面粗糙度为0.76 µm的光滑抛光表面。可用于粗抛光操作，因为高材料去除率是主要问题。此外，交叉扫描抛光方式比横向抛光方式获得了更好的无裂纹和凹坑的表面质量，但抛光效率较低。此外，在适当的加工条件下，采用15 µm的扫描间距，结合高激光脉冲能量和交叉扫描抛光方式，获得了表面粗糙度为0.76 µm的光滑抛光表面。可用于粗抛光操作，因为高材料去除率是主要问题。此外，交叉扫描抛光方式比横向抛光方式获得了更好的无裂纹和凹坑的表面质量，但抛光效率较低。此外，在适当的加工条件下，采用15 µm的扫描间距，结合高激光脉冲能量和交叉扫描抛光方式，获得了表面粗糙度为0.76 µm的光滑抛光表面。