The lubricant behaviours under varying contact conditions were investigated by conducting pin-on-strip tests between P20 tool steel and AA7075 aluminium alloy using an automated testing system, Tribo-Mate. The effects of temperature changes, and rapid load and speed changes on the coefficient of friction (COF) and lubricant breakdown phenomenon were experimentally studied. The evolutions of COF showed three distinct stages, indicating the transformation from boundary lubrication condition to dry sliding condition. The value of COF at the initial stage was found to increase with increasing temperature. The increase of temperature, contact load and sliding speed caused an earlier breakdown of the lubricant. An interactive friction model was developed to predict friction evolutions at varying contact conditions. A close agreement with errors less than 6.8% were achieved between the model predictions and experimental results.

通过使用自动测试系统Tribo-Mate在P20工具钢和AA7075铝合金之间进行销钉连接测试，研究了在不同接触条件下的润滑性能。实验研究了温度变化，快速载荷和速度变化对摩擦系数（COF）和润滑剂破坏现象的影响。COF的演变显示出三个不同的阶段，表明从边界润滑条件到干滑条件的转变。发现初始阶段的COF值随温度升高而增加。温度，接触负载和滑动速度的增加导致润滑剂较早地分解。开发了交互式摩擦模型来预测在不同接触条件下的摩擦演变。