采用粉末冶金方法(机械合金化+真空热压烧结)制备了不同SrCO₃和Ag 含量的NiCrW-Al₂O₃-SrCO₃-Ag金属陶瓷复合材料, 利用UMT-3考察复合材料在室温至1 000 ℃条件下的摩擦磨损性能, 利用SEM、EDS、XRD等表征分析其显微组织、物相组成及其磨损机理. 结果表明: 热压烧结过程中, SrCO₃高温分解, 并与Al₂O₃反应生成SrAl₄O₇, 同时生成了Cr₂O₃和NiCr₂O₄等新相. 分别添加质量分数10% SrCO₃和Ag的复合材料在宽温域内的摩擦磨损性能最优, 归因于在中高温阶段复合材料摩擦表面发生摩擦化学反应生成了SrCrO₄和NiO等润滑相, 与复合材料中的Ag、NiCr₂O₄等润滑相形成协同润滑, 使得复合材料在400~1 000 ℃宽温域范围内具有优异的摩擦磨损性能.

NiCrW-Al₂O₃-SrCO₃-Ag composites with different contents of SrCO₃ and Ag were fabricated by powder metallurgical method (mechanical alloying and vacuum hot-pressing sintering). The friction and wear properties were tested by UMT-3 from room temperature to 1 000 ℃. The microstructures, phase compositions and wear mechanism of the composites were analyzed by scanning electron microscopy, energy dispersive spectrocopy and X-ray diffraction.The results show that the decomposition of SrCO₃ and the formation of SrAl₄O₇ during the hot-pressing. Meanwhile, the new phases such as Cr₂O₃ and NiCr₂O₄ were found. The composite with addition of 10% SrCO₃ and 10% Ag exhibited the best friction and wear properties in a wide temperature range and that was attributed to the formation of the tribolayers containing oxides (SrCrO₄ and NiO) by tribo-chemical reactions during the medium-high temperature process.Together with Ag and NiCr₂O₄ in composites, SrCrO₄ and NiO worked synergistically to improve the tribological properties of the composites in a wide range of temperatures (400~1 000 ℃).