Abstract High purity engineering ceramics have been increasingly used for constituting novel lightweight ceramic composite armors along with various FRP materials. In the assembly process of ceramic composite armors, a large number of hole processing is required. Usually, diamond trepanning drills are preferentially adopted for machining relatively large holes of engineering ceramics. However, during drilling high purity armor engineering ceramics, the diamond tools are usually worn considerably due to their high dynamic compression strength and high hardness. In this study, taking the high purity alumina armor ceramics (99 wt% Al2O3) as machining object, the comprehensive wear features of the sintered diamond trepanning drill have been intensively studied through SEM examinations, including the microscopic wear morphologies of diamond grains and matrix binding agent, the diamond abrasion mechanism, the wear disfigurations of the drill labial surface and the drill slipping mechanism. According to the discussed results, the wear process of the diamond grains at the matrix labial surface can be divided into three stages: intact crystal, slight wear and severe wear stages. The quicksand phenomenon occurrence around the diamond grains is the typical feature of the matrix binding agent wear. The normal grinding of the drill can be interrupted by the severe inner-trumpet-shape wear and the cutting-groove wear of the drill labial surface. In most situations, only the slight inner-trumpet-shape wear occurs for the drill, which does not affect the normal drilling operation. The drill slipping is mainly attributed to the fact that most exposed diamond grains at the drill labial surface have been rubbed down into a polished planar shape and totally blunted. The results achieved in this study can provide helpful references for the performance improvement design of the sintered diamond trepanning drill.

中文翻译：

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烧结金刚石套孔钻加工氧化铝铠装陶瓷时的显微磨损研究

摘要 高纯度工程陶瓷与各种玻璃钢材料一起越来越多地用于构成新型轻质陶瓷复合装甲。在陶瓷复合装甲的装配过程中，需要进行大量的孔加工。对于工程陶瓷较大的孔，通常优先采用金刚石套料钻头。然而，在钻削高纯度装甲工程陶瓷时，金刚石工具由于其高动态抗压强度和高硬度，通常磨损很大。本研究以高纯氧化铝铠装陶瓷（99 wt% Al2O3）为加工对象，通过扫描电镜对烧结金刚石环钻的综合磨损特性进行了深入研究，包括金刚石晶粒和基体结合剂的微观磨损形貌、金刚石磨损机理、钻头唇面磨损变形和钻头滑移机理。根据讨论结果，基体唇面金刚石晶粒的磨损过程可分为三个阶段：完整晶体、轻微磨损和严重磨损阶段。金刚石晶粒周围出现的流砂现象是基体结合剂磨损的典型特征。钻头的正常磨削会因钻头唇面严重的内喇叭形磨损和切槽磨损而中断。在大多数情况下，钻头只发生轻微的内喇叭形磨损，不影响正常的钻井作业。钻头打滑主要是由于钻头唇面上大部分暴露的金刚石颗粒被磨成抛光的平面形状并完全变钝。研究结果可为烧结金刚石环钻的性能改进设计提供有益的参考。