海水环境下CoCrFeW合金的摩擦学性能研究

TRIBOLOGICAL PROPERTIES OF COCRFEW ALLOY UNDER SEAWATER CONDITION

采用粉末冶金的方式制备了W(0 wt%、4 wt%、8 wt%和12 wt%)强化的CoCrFe基合金,系统研究了合金在海水环境下的摩擦学性能。利用往复式球-盘摩擦磨损试验机,与GCr15钢球配副,研究了海水环境下合金在不同滑动速度和载荷条件下的摩擦磨损行为;使用X射线衍射仪、扫描电子显微镜和能谱仪分析了合金的相组成和磨损机理。结果表明,CoCrFeW合金主要由ε(hcp)、γ(fcc)、Fe-Cr和Cr_(2)O_(3)相组成,合金结构致密,硬度和密度均随W含量增加而升高。总体上说,合金的摩擦因数随着滑动速度和载荷的增加均呈降低趋势,且在高速条件下随W含量的增加先升高后减小,高载条件下添加W的试样,摩擦因数随W含量增加先减小后上升;磨损率随滑动速度、载荷和W含量的增加均降低。海水组分反应产物和合金腐蚀产物起到了减摩抗磨作用。W显著提升了合金在海水环境下的抗磨损性能,添加8 wt%W的试样CW8表现出最佳摩擦学性能。随W含量增加,合金磨损机制由塑性变形和疲劳磨损转变为磨粒磨损。

In this study,CoCrFe-based alloys reinforced by W(0 wt%,4 wt%,8 wt%and 12 wt%)were prepared by powder metallurgy,and the tribological properties of the alloys under seawater environment were systematically studied.The friction and wear behavior of the alloy under different loads and sliding speeds in seawater was studied using a reciprocating ball-on-disk friction and wear tester sliding against with GCr15 steel ball;X-ray diffractometer,scanning electron microscope and energy dispersive x-ray analyzer were used to analyze the phase composition and wear mechanisms of the alloys.The results show that the CoCrFeW alloy is composed ofε(hcp),γ(fcc),Fe-Cr and Cr_(2)O_(3) phases.The alloy structure was compact,and the hardness and density increased with the increase of W content.Generally speaking,the friction coefficients of the alloy showed a decreasing trend with the increase of sliding speed and load,and increased first and then decreased with the increase of W content under high-speed conditions.Under high load conditions,the friction coefficients of W-added specimens first decreased and then increased with the increase of W content.The wear rates decreased with the increase of sliding speed,load and W content.Seawater component reaction products and alloy corrosion products had friction-reducing and antiwear action.W significantly improved the wear resistance of the alloy in seawater environment,and the specimen CW8 with 8 wt%W added showed the best tribological performance.As the W content increased,the alloy wear mechanisms changed from plastic deformation and fatigue wear to abrasive wear.