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以常规和纳米团聚体ZrO2-7wt%Y2O3复合陶瓷粉末为材料,采用等离子喷涂工艺在TC4钛合金表面制备了常规和纳米结构陶瓷涂层,并对其进行冲蚀实验,研究了涂层微观组织和性能对涂层抗冲蚀性能的影响,以及不同工艺参数下涂层冲蚀性能。用扫描电镜(SEM)和XRD分析了涂层组分和微观结构,同时利用显微硬度计对涂层的硬度进行了测试。结果表明,等离子喷涂纳米ZrO2涂层抗冲蚀性能明显高于常规ZrO2涂层。当冲蚀角为90°时冲蚀失重最大,表现为脆性冲蚀,随着速度的增大冲蚀失重也随之增加。等离子喷涂纳米ZrO2涂层由熔化区和部分熔化区组成,部分熔化区属微纳米结构,熔化区在沉积急冷和冲击应力的作用下会形成细晶,微纳米结构与细晶共同作用下的纳米陶瓷涂层的平均粒度将远远小于常规陶瓷涂层的平均粒度,使其硬度增加;微纳米区域在涂层中其局部晶界的强度特别高,裂纹难以沿着晶界扩展,起到了良好的增韧的作用,硬度和韧性的提高使涂层的抗冲蚀性能增强。
Conventional and nano-agglomerate ZrO2-7wt% Y2O3 composite ceramic powders were used as materials to prepare conventional and nanostructured ceramic coatings on TC4 titanium alloy by plasma spray process. The erosion experiments were carried out on the surface of TC4 titanium alloy. And performance of the coating on the erosion resistance, as well as the coating process under different erosion parameters. The composition and microstructure of the coating were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The hardness of the coating was also tested by micro-hardness tester. The results show that the plasma spraying nano ZrO2 coating erosion resistance was significantly higher than the conventional ZrO2 coating. When the erosion angle is 90 °, the erosion weight loss is the largest, showing brittle erosion, along with the increase of the erosion weight loss also increases. Plasma spraying Nano-ZrO2 coating consists of a melting zone and a partial melting zone. Part of the melting zone is a micro-nano structure. The melting zone will form fine crystals under the effect of rapid cooling and impact stress deposition. The nano-sized nano- The average particle size of the ceramic coating will be much smaller than the average particle size of the conventional ceramic coating to increase its hardness; the micro-nano region in the coating its local grain boundary strength is particularly high, the crack is difficult to spread along the grain boundary, played a good Toughening effect, the hardness and toughness of the coating to enhance the erosion resistance.