铸造CoCrW合金的高温耐磨性能研究

Study on High Temperature Wear-Resistant Properties of the as-cast CoCrW Alloys

以铸造CoCrW合金为研究对象,借助XRD、SEM和EDS在研究其微观组织基础上,通过高温摩擦磨损实验研究了铸造CoCrW合金高温耐磨性能。结果表明:铸态CoCrW合金组织主要由碳化物强化相和γ-Co基体相组成,其中碳化物主要为M23C6、M6C碳化物,在γ-Co基体中呈大小不同的块状分布;合金的摩擦系数和磨损失重随着实验温度的升高而逐渐降低,600℃时合金的耐磨性能最好,但当实验温度超过800℃时,合金发生明显氧化,耐磨性能下降。不同温度下CoCrW合金的磨损机制均为磨粒磨损、剥落和氧化磨损的共同作用。

The microstructure and the wear-resistant properties of the as-cast CoCrW alloys at different temperatures were investigated by combining XRD,SEM,EDS and high temperature friction and wear tests.The results showed that the microstructure of the as-cast CoCrW alloys was composed of M23C6,M6C andγ-Co phases.The block-shaped carbides with different sizes were distributed intoγ-Co matrix.The friction coefficients and wear loss of the alloys gradually decreased with the increase in temperature and the wear resistance of the alloys was the best at 600℃.When temperature was above 800℃,the wear resistance of the alloy became worse due to oxidation.Further analysis indicated that the mechanism that controls the wear-resistant property of the CoCrW alloys at different temperatures was the interaction of abrasive wear,spalling and oxidation wear.