Silicon carbide (SiC) ceramics, as a superhard nonmetallic material, would induce severe tool wear during drilling. To ensure the quality of processing, the drill bits must be replaced in advance before failure, which leads to serious waste without effective usage. Aiming at the tool reliability problem determined by the tool wear during drilling of the high hardness nonmetallic materials, this article proposed a reliability analysis method of sintered diamond drill bit for machining SiC ceramics based on the distribution of tool degradation increment and the modeling of gamma process, and a tool reliability model of degradation increment was established based on the Bayesian theory. The drilling experiment of sintered SiC ceramics was carried out by sintering diamond drill bit to obtain the degradation increment data. The accuracy of the model was tested by the reliability model deviation rate, which indicated that the reliability model with considering individual differences was more accurate. This research can provide a theoretical model and analytical method for improving the reliability of the nonmetallic brittle material processing tools.

碳化硅（SiC）陶瓷作为超硬非金属材料，会在钻孔过程中引起严重的工具磨损。为了确保加工质量，必须在出现故障之前提前更换钻头，这会导致严重浪费，而无法有效使用。针对高硬度非金属材料在钻削过程中刀具磨损所引起的刀具可靠性问题，提出了一种基于刀具退化增量分布和伽马过程建模的SiC陶瓷加工金刚石烧结钻头可靠性分析方法。并基于贝叶斯理论建立了退化增量的工具可靠性模型。通过烧结金刚石钻头进行了烧结SiC陶瓷的钻孔实验，得到了劣化增量数据。通过可靠性模型偏差率测试了模型的准确性，这表明考虑个体差异的可靠性模型更为准确。该研究可以为提高非金属脆性材料加工工具的可靠性提供理论模型和分析方法。