Abstract Ti–Si–C (TSC) composite coatings were fabricated by plasma spraying using Ti/Si/graphite agglomerates as feedstock. Ar-annealing was carried out to reduce the intrinsic defects and increase the performance of the as-sprayed TSC coating. The effects of the annealing temperature (500–900 °C) on the microstructures and mechanical performances of the TSC coatings were investigated. All TSC coatings consisted of TiC, Ti5Si3 and MAX phase Ti3SiC2. With the increase in temperature (>700 °C), TiC became predominant, while the Ti3SiC2 phase content increased, which was accompanied by a decrease in Ti5Si3 content. The high -temperature annealing (>700 °C) led to a homogenous microstructure with a relatively low porosity and increased number of micro-cracks. Notably, the hardness and fracture toughness of the TSC coating were simultaneously increased after the annealing, from 1164 HV to 1.96 MPa m1/2 to 1560 HV and 3.45 MPa m1/2, respectively. The formation of nanoscale TiC and Ti5Si3 with a network distribution, uniform and dense microstructure, and toughening effects of Ti3SiC2 and micro-cracks provided the high mechanical performances of the TSC composite coatings.

中文翻译：

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通过后退火提高等离子喷涂 Ti-Si-C 纳米复合涂层的硬度和韧性

摘要 Ti-Si-C (TSC) 复合涂层是以 Ti/Si/石墨团聚体为原料通过等离子喷涂制备的。进行Ar退火以减少固有缺陷并提高喷涂TSC涂层的性能。研究了退火温度（500-900°C）对 TSC 涂层微观结构和机械性能的影响。所有 TSC 涂层均由 TiC、Ti5Si3 和 MAX 相 Ti3SiC2 组成。随着温度的升高（>700 °C），TiC 占主导地位，而 Ti3SiC2 相含量增加，伴随着 Ti5Si3 含量的减少。高温退火（> 700 °C）导致具有相对较低孔隙率和增加的微裂纹数量的均匀微观结构。尤其，TSC 涂层的硬度和断裂韧性在退火后同时增加，分别从 1164 HV 到 1.96 MPa m1/2 到 1560 HV 和 3.45 MPa m1/2。纳米级 TiC 和 Ti5Si3 的形成具有网络分布、均匀致密的微观结构以及 Ti3SiC2 的增韧作用和微裂纹，为 TSC 复合涂层提供了较高的机械性能。