等离子喷涂WC-Co涂层的磨料磨损

Abrasive Wear of WC Co Plasma Spraying Coatings

采用等离子喷涂方法在真空和大气环境下喷涂制备了不同Ｃｏ基含量的ＷＣ－Ｃｏ涂层，用橡胶轮磨损试验机进行了高应力和低应力磨料磨损试验，并对涂层的相结构及磨损机理进行了研究。结果表明：真空喷涂涂层的耐磨性明显优于大气中喷涂涂层的耐磨性。涂层的耐磨性主要取决于涂层的致密程度和涂层中的相，而与涂层硬度的关系不是太大。等离子喷涂ＷＣ－Ｃｏ涂层的磨损机理是在低应力磨料磨损情况下硬度低的富Ｃｏ区先磨损，硬度高的ＷＣ相起到阻止石英砂磨损的作用，大大地降低了涂层的磨损；在高应力磨料磨损时，ＷＣ发生破裂，抗磨作用不是太大。

WC Co coatings with different Co content were made by plasma spraying technique both in vacuum and in air environment.The high stress and the low stress abrasive wear tests for the coatings were carried out using a rubber wheel abrasive wear tester.The results show that the wear resistance of the coatings sprayed in vacuum is better than that in air environment.The wear resistance of the coatings depends mainly on the phases and porosity.During the low stress abrasive wear,the rich Co zones of the coatings,due to their low hardness,are worn prior to the tungsten carbides,and the higher hardness tungsten carbides play a role to resist to the abrasion from silica,but the tungsten carbides crack off during high stress abrasive wear.