The lubricant behaviour at elevated temperatures was investigated by conducting pin-on-disc tests between P20 tool steel and AA7075 aluminium alloy. The effects of temperature, initial lubricant volume, contact pressure and sliding speed on the lubricant behaviour (i.e. evolutions of the coefficient of friction (COF) and the breakdown phenomenon) were experimentally studied. The evolutions of COF at elevated temperatures consisted of three distinct stages with different friction mechanisms. The first stage (stage I) occurred with low friction when the boundary lubrication was present. The second stage (stage II) was the transition process in which the COF rapidly increased as the lubricant film thickness decreased to a critical value. In the final plateau stage (stage III), lubricant breakdown occurred and intimate contact at the interface led to high friction values. At the low friction stage (stage I), the value of COF increased with increasing temperature. The increase in temperature, contact pressure and sliding speed as well as the decrease in initial lubricant volume accelerated the lubricant breakdown.

通过在P20工具钢和AA7075铝合金之间进行针-盘试验，研究了高温下的润滑剂性能。实验研究了温度，初始润滑剂量，接触压力和滑动速度对润滑剂行为（即摩擦系数（COF）的演变和击穿现象）的影响。COF在高温下的演变包括三个不同的阶段，具有不同的摩擦机理。当存在边界润滑时，第一阶段（第一阶段）摩擦很小。第二阶段（阶段II）是过渡过程，其中COF随着润滑剂膜厚度减小到临界值而迅速增加。在最后的高原阶段（第三阶段），发生润滑剂故障，界面处的紧密接触导致高摩擦值。在低摩擦阶段（阶段I），COF值随温度升高而增加。温度，接触压力和滑动速度的增加以及初始润滑剂体积的减少加速了润滑剂的分解。