Abstract Monolithic TiC and TiC particulate ceramic composite containing 30 and 50 mol.%SiC were consolidated and synthesized using spark plasma sintering (SPS) without sintering aids. The as-sintered bulk samples microstructural evolution and dry sliding room-temperature tribological properties against Al2O3 ball were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman analysis. The role of coefficient of thermal expansion (CTE) mismatch between TiC and SiC as well as cubic to hexagonal SiC phase transformation on the evolution of residual stresses in the composite was also investigated. The friction and wear properties of the monolithic TiC were superior to that of the composite with frictional heating-induced tribo-oxidation playing a dominant role in the wear mechanism. The increase in friction and wear of the composite is attributed to wear-induced stress-relaxation of the previously trapped residual stresses in the composite leading to extensive ripplocation of the TiC grains and consequent SiC grain pull-outs. Herein, we report for the first time on the wear-induced mechanical exfoliation of carbon, its subsequent decomposition into graphite and eventual deformation by micromechanism involving nucleation and propagation of ripples.

中文翻译：

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TiC基复合材料干滑动磨损过程中的磨损诱导裂变

摘要 使用放电等离子烧结（SPS）在不使用烧结助剂的情况下固结并合成了含有 30 和 50 mol.% SiC 的整体 TiC 和 TiC 颗粒陶瓷复合材料。使用 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和拉曼分析表征了烧结块状样品的微观结构演变和干滑动室温摩擦学性能对 Al2O3 球的影响。还研究了 TiC 和 SiC 之间的热膨胀系数 (CTE) 失配以及立方到六方 SiC 相变对复合材料中残余应力演变的作用。整体式 TiC 的摩擦磨损性能优于复合材料，摩擦加热引起的摩擦氧化在磨损机制中起主导作用。复合材料摩擦和磨损的增加归因于磨损引起的复合材料中先前捕获的残余应力的应力松弛，导致 TiC 晶粒的广泛波纹和随之而来的 SiC 晶粒拉出。在此，我们首次报告了碳的磨损引起的机械剥落，其随后分解成石墨并最终通过涉及波纹成核和传播的微观机制变形。复合材料摩擦和磨损的增加归因于磨损引起的复合材料中先前捕获的残余应力的应力松弛，导致 TiC 晶粒的广泛波纹和随之而来的 SiC 晶粒拉出。在此，我们首次报告了碳的磨损引起的机械剥落，其随后分解成石墨并最终通过涉及波纹成核和传播的微观机制变形。复合材料摩擦和磨损的增加归因于磨损引起的复合材料中先前捕获的残余应力的应力松弛，导致 TiC 晶粒的广泛波纹和随之而来的 SiC 晶粒拉出。在此，我们首次报告了碳的磨损引起的机械剥落，其随后分解成石墨并最终通过涉及波纹成核和传播的微观机制变形。