Ti_2AlNb基合金等离子渗碳层的组织结构与摩擦性能

Microstructure and Tribological Properties of the Plasma Carburized Layer on Ti_2AlNb Alloy Surface

采用双层辉光等离子表面合金化技术在Ti2AlNb基合金表面渗碳以提高其耐磨性,通过扫描电子显微镜、X射线衍射仪、动态显微硬度系统等对渗碳层的微观组织、相组成及动态显微硬度进行表征,并采用HT2500型摩擦磨损试验机对其耐磨性进行测试。结果表明,经等离子渗碳后Ti2AlNb基合金可获得厚度约11μm的表面渗碳层,且该层碳元素含量由表及里呈梯度变化。合金渗碳层主要由纯C、TiC及Ti2AlC相组成,表面动态显微硬度达9.61 GPa。渗碳试样的比磨损率仅为基体合金的1.82%,耐磨性能大大提高。

Ti2AlNb alloy was modified by double glow plasma surface carburizing to improve its wear resistance.The microstructure,phase composition and dynamic microhardness of the carburized layer was characterized through SEM,XRD and dynamic microhardness system.And its wear resistance was tested through a HT2500-type friction and wear tester.The results show that about 11 μm carburized layer is obtained on the Ti2AlNb alloy surface,and its carbon content decreases gradually from surface to matrix.The main components of the carburized layer are pure C,TiC and Ti2AlC.The surface dynamic microhardness of the carburized layer is 9.61 GPa.The specific wear rate of the carburized sample is only 1.82% of the matrix alloy.The wear resistance of Ti2AlNb alloy is greatly increased by carburization.