TiB_(2)/Al复合材料摩擦行为研究

Study on Friction Behavior of TiB_(2)/Al Composites

采用挤压铸造法制备TiB_(2)/Al复合材料并发现其在低载高速下具有自润滑特性,因此借助于摩擦试验研究了载荷、滑动速度、摩擦副对该材料摩擦行为的影响。结果表明,低载高速条件下TiB_(2)/Al复合材料与GCr15轴承钢室温干摩擦时,随着滑动时间的延长,平均摩擦系数未出现明显的上升或下降过渡现象,仅瞬时摩擦系数呈现出不同程度的湍流波动状态。滑动速度为0.8 m/s时,随着载荷的增大,TiB_(2)/Al复合材料与GCr15干摩擦的平均摩擦系数基本不变,但瞬时摩擦系数的波动幅度减小,摩擦系数的标准偏差减小。载荷为0.49 N时,随着滑动速度的增大,平均摩擦系数没有明显的变化,在0.165~0.255之间波动。与等速度变载荷时相比,等载荷变速度条件下TiB_(2)/Al复合材料的摩擦系数分散性比较大。采用GCr15为摩擦副时,TiB_(2)/Al复合材料的瞬时摩擦系数湍流波动较复合材料自摩擦时要大些。自磨时复合材料的平均摩擦系数为0.08左右,与GCr15对磨时平均摩擦系数为0.18左右。

30vol%TiB_(2)/Al composites were fabricated by squeeze casting technology,and its self-lubricating characteristics under low load and high speed were found.Therefore,the influence of load,sliding velocity and friction pair on the friction behavior of the material was studied by friction tests.The results show that under low load and high speed,TiB_(2)/Al composite and GCr15 bearing steel are under dry friction at room temperature,with the extension of sliding time,the average friction coefficient does not show obviously increasing or decreasing phenomenon,only the instantaneous friction coefficient presents different degree of turbulent fluctuation.In addition,At sliding velocity of 0.8 m/s,with the increase of the load,the average friction coefficient of TiB_(2)/Al composite with GCr15 is basically unchanged,but the fluctuation amplitude of the instantaneous friction coefficient decreases,and the standard deviation of is friction coefficient decreases.While at 0.49 N,the average friction coefficient does not change significantly with the increase of sliding velocity,fluctuating between 0.165~0.255.The friction coefficient dispersion of TiB_(2)/Al composites under constant load and variable velocity is higher than that under constant velocity and variable load.When GCr15 is used as friction pair,the turbulent fluctuation of instantaneous friction coefficient is larger than that of composite itself.The average friction coefficient of composites is stable at about 0.08.When grinding with GCr15,the average friction coefficient is stable at about 0.18.