石墨密封材料高温摩擦磨损行为及预测

利用HT-1000型高温摩擦磨损试验机研究了石墨M210密封材料高温下摩擦磨损性能，采用扫描电子显微镜（SEM）观察分析了磨损表面形貌.基于试验数据，通过灰色理论GM（1，1）建立了摩擦因数和磨损率预测模型.结果表明:石墨M210密封材料摩擦因数呈先增大再减小，而后趋于一稳定值，试验温度为450℃时，摩擦因数最小；磨损率随着试验温度升高而增大.试验温度在低于300℃，磨损表面具有明显的黏着、撕裂和无序的塑流动痕迹，高于400℃时，塑流动痕迹具有明显的方向性，出现了剥落和断裂痕迹.温度较低时，石墨材料表面主要是水汽物理吸附膜起润滑作用，随着试验温度升高，由物理吸附膜润滑逐渐转向反应膜润滑.基于试验数据建立了精度等级均为1级的摩擦因数和磨损率的预测模型. 

Friction/wear behaviors and predication of graphite seal material under high temperature

The tribological properties of graphite M210 seal material under high temperature were investigated on a HT-1000 high temperature friction/wear tester.The worn surface of graphite pin was observed by scanning electronic microscope (SEM).The predication model on friction coefficient and wear rate was established by grey theory GM (1, 1) based on the test data.The results show that the friction coefficient of graphite M210 seal material gradually augmented,then gradually diminished,and reached a steady value with the test time.The value of friction coefficient was minimal when the temperature was 450℃.The wear rate increased with the temperature rise.The worn surface was characterized by obvious adhesion,laceration and unordered plastic flow under temperature 300℃.The plastic flow trace had obvious directivity,and the desquamation and the rift were found on the worn surface when the temperature was above 400℃.The lubrication action was mostly dependent of the physically absorbed film by water vapor at lower temperature.With the temperature rise,the lubrication action turned to reaction film,and the lubrication of physical adsorbed film disappeared.The predication model for friction coefficient and wear rate was established based on test data by the gray theory,and the precision grade of the model was the first grade by the grade verification.