摩擦热对UHMWPE/钢摩擦副摩擦性能的影响
Effects of Friction Heat on Tribological Properties of UHMWPE
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摘要: 通过控制销盘试验中的散热条件测定了摩擦热对UHMWPE/钢摩擦副摩擦性能的影响;利用统计学相关系数理论对摩擦系数和表层温度的相关性进行定量比较,发现不良散热条件使其相关系数显著增大;根据Taylor Hobson轮廓仪测量试样表面形貌三维初始表面高度,尝试用元胞自动机方法进行了摩擦表面温度分布模拟计算,并结合磨损表面形貌分析探讨摩擦热对UHMWPE磨损机理的影响.结果表明:摩擦系统的热传导条件严重影响UHMWPE的摩擦性能;摩擦热效应使得局部接触表面温度超过熔点,摩擦热的积累效应使UHMWPE的磨损机理由粘着磨损变为熔融剪切磨损;在聚合物材料的摩擦试验及应用研究中必须考虑摩擦热的影响.Abstract: Influence of friction heat to UHMWPE/steel friction couple was studied by controlling condition of heat dissipation in pin-on-disc tester.Application of statistical correlation coefficient to describe quantitatively the correlation between friction coefficient and surface temperature indicates that poor heat dissipation tended to increase correlation coefficient of friction coefficient and surface temperature.Peak values from Taylor Hobson's 3D measurement of surface topography of UHMWPE before testing were used for forming cellular automaton grid to simulate and calculate distribution of friction surface temperature.Results suggest that:(i) condition of friction heat dissipation seriously affects tribological characteristics of UHMWPE;(ii) generation of frictional heat is likely to rise the temperature of some local contact points beyond their melting point;(iii) accumulation of friction heat changes adhesion wear to "molten and shearing" wear;and(iv) friction heat effect to tribological properties of polymers must be specifically considered in both experiments and practical applications.