三维网络SiC对铝合金干摩擦磨损性能的影响

Effect of 3D-meshy SiC on the dry friction and wear of aluminum alloys

用销-盘式高温摩擦磨损实验机研究了LF3铝合金及三维网络SiC(体积分数分别为10％、20％、30％)增强LF3铝基复合材料的干摩擦磨损性能,测量了复合材料及基体合金在室温和高温(25～300℃)条件下的摩擦系数和磨损率,用扫描电镜(SEM)观察其磨损表面,研究了三维网络SiC对铝合金磨损机制的影响。结果表明:复合材料的干摩擦磨损性能远优于基体合金(LF3),而且随着温度的升高,复合材料的抗磨损性能明显提高。三维网络SiC在磨损表面形成硬的微凸体起承载作用,同时其独特的结构制约基体合金的塑性变形和高温软化,并保护在磨损表面形成的氧化膜。在相同实验条件下,复合材料的摩擦系数、磨损率随着增强体的体积分数的增加而降低。复合材料的摩擦系数在滑行过程中的稳定性明显高于基体合金。

The dry friction and wear behaviors of the alloy (LF3) and aluminum-matrix composites reinforced with the different volume fraction (10%, 20%, 30%) of 3D-Meshy SiC were investigated by means of a pin-on-disk type wear apparatus. Friction coefficients and wear rates of the matrix alloy and the composites with 10%-30% SiC were measured over a temperature range of 25-300°C. The Scan Electronic Microscope (SEM) analyses were undertaken to observe the worn surface and clarify the effect of 3D-meshy SiC on the wear mechanisms of the aluminum alloy. The experiments showed that the dry friction and wear behaviors of composites were superior to those of the matrix alloy (LF3), and the higher the temperature, the better the wear-resistance of composites (compared with the matrix) showed. The SiC in the 3D-meshy, which formed hard convex bodies on the worn surface, plays the role of supporting the load. At the same time, its unique structure restricts the plastic deformation and the high-temperature softening, and protects the oxide film (Al2O3) on the worn surface. Under the same conditions, the friction coefficients and wear rates of composites decreased with the increase of volume fraction of 3D-meshy SiC. In addition, the friction coefficients of composites were more stable than those of the matrix alloy in the process of sliding.