铝基石墨复合材料的摩擦特性与机理分析

研究了低速、低载荷滑动摩擦条件下铝基石墨复合材料的摩擦学特性．结果表明：在相对滑动初期，复合材料的摩擦系数与基体合金相近；随着摩擦过程的进行，复合材料的摩擦系数逐渐下降并最终趋于稳定；石墨含量越高，达到稳定摩擦系数所需的时间越短；摩擦系数的变化与摩擦表面石墨成膜过程相对应；摩擦系数达到稳定状态时自润滑膜覆盖面积大约为摩擦表面的８５％ ，这时自润滑膜在摩擦表面上生成和剥落过程达到动态平衡．

Analysis on Mechanism and Tribological Behavior of Al Alloy Based Graphite Composites

The tribological behaviors of Al graphite composites under low load and low sliding speed were studied with a Falex machine. At the initial stage of sliding, the friction coefficient of the composites was nearly the same as that of matrix alloy. With increasing of friction duration, the coefficient of friction decreased and stabilized at about a half of that of the matrix alloy. The higher the graphite particle content in the composites, the less it takes to reach the stable friction coefficient. The reduction in friction of composites is because of the formation of graphite lubricating film during sliding. When the area of self lubricant film exceeds 85%, the friction coefficient keeps steady. The dynamic equilibrium of graphite film is kept due to the balance of the squeezing out and restricting of graphite particles in the surface and subsurface of composites by the deformation of matrix.