镍基复合材料在水环境中的摩擦学性能及磨损机理研究

本文考察了Ni-SiC-石墨系复合材料在水环境中的摩擦学性能,并研究其磨损机理.结果表明:复合材料在水环境中的摩擦系数比干摩擦降低了一半左右,磨损率仅为干摩擦下的1/15,水环境中,负荷和速度的变化对摩擦系数的影响不大,摩擦系数基本保持在0.28～0.32之间,磨损率随负荷和滑动速度的增加而不断增加.磨损表现为机械微切削;摩擦副表面吸附水的边界润滑作用以及水的冷却作用使材料容易耗散摩擦热,塑性变形减小,严重粘着磨损明显减轻.水的存在使不锈钢偶件更容易发生氧化,同时暴露于磨损表面的SiC以及由于水的渗透而导致与基体脱粘的SiC,易被氧化生成SiO2,进而SiO2发生水合反应在磨擦对偶表面生成不均匀的SiO2·nH2O水合反应膜,起到了一定的减磨润滑作用,显著降低摩擦系数和磨损率.

Investigation on the Tribological Properties and Wear Mechanisms of Nickel Based Composite under Water Lubrication

The comparative researches of the tribological characteristic of Nickel-Silicon carbide-Graphite composite under water lubrication and dry-friction were conducted.The result indicated that the friction coefficient of Ni-based composite under water lubrication was about one half of that under dry friction and wear rate was only one fifteenth in the same way.The friction coefficient did not relay on the normal load and sliding speed greatly under water lubrication,and it maintains between 0^28 and 0^32,whereas the wear rate of composite increases with load and sliding speed.The main wear mechanisms were dominant by abrasive and fatigue under water lubrication.Being in existence of water,the oxidation of the stainless steel couple accelerated,meanwhile Silicon carbide reacted with water and a thin lubricating film of SiO-25nH-2O were formed which could observably reduce the friction coefficient and wear rate as also.