MoSi2-Mo5Si3-Mo5SiB2/SiC配对副的摩擦磨损性能

MoSi₂-Mo₅Si₃-Mo₅SiB₂复合材料是一种很有发展前景的高温耐磨材料，但MoSi₂-Mo₅Si₃-Mo₅SiB₂/SiC配对副的干滑动摩擦磨损性能尚不清楚. 本文中通过销-盘式干滑动摩擦磨损试验，考察了MoSi₂-Mo₅Si₃-Mo₅SiB₂/SiC配对副在不同温度(25~1 000 ℃)和载荷下(2.5~10 N)的摩擦学特性. 结果表明:试验温度和载荷对MoSi₂-Mo₅Si₃-Mo₅SiB₂/SiC配对副的摩擦系数影响较大，而对其磨损率影响较小. 载荷为5 N时，在25~1 000 ℃区间，摩擦系数和磨损率分别在0.11~0.43和0.513×10-7~0.544×10-7 mm3/(N·m)范围；在25~400 ℃时，磨损机制以轻微的氧化和黏着磨损为主，在600~1 000 ℃磨损机制主要表现为严重的氧化和黏着磨损. 在1 000 ℃时，随着载荷(2.5~10 N)的增加，摩擦系数和磨损率分别为0.29~0.38和0.540×10-7~0.547×10-7 mm3/(N·m)；载荷为2.5~10 N时，始终存在黏着和氧化磨损；载荷为7.5~10 N时，材料磨损表面还伴随碾压塑性变形的特征. 

Friction and Wear Properties of MoSi2-Mo5Si3-Mo5SiB2 Composite against SiC

MoSi₂-Mo₅Si₃-Mo₅SiB₂ composite is a promising wear resistance material at elevated temperature. However, the tribological properties of MoSi₂-Mo₅Si₃-Mo₅SiB₂ against SiC were not fully understood. In the present study, the friction and wear properties of the composite at 25~1 000 ℃ and 2.5~10 N were investigated using a ball-on-disk sliding tests. The results show that both test temperatures and applied loads had significant effect on the coefficient of friction (COF), while have insignificant effect on the wear rate. The COFs and wear rates of the MoSi₂-Mo₅Si₃-Mo₅SiB₂ composite at 25~1 000 ℃ were in the ranges of 0.11~0.43 and 0.540×10-7~0.547×10-7 mm3/(N·m), respectively. The mild oxidation and adhesive wears were main wear mechanisms for the composite tested below 400 ℃. At 600 ~ 1 000 ℃, the wear mechanisms were dominated by severe oxidation wear and adhesive wear. The COFs and wear rates of the composite, at 1 000 ℃ under load of 2.5~10 N, were in the ranges of 0.29~0.38 and 0.540×10-7~0.547×10-7 mm3/(N·m), respectively. The dominant wear mechanisms of the composite at 2.5~10 N were adhesive wear and oxidation wear, and accompanied with plastic deformation at 7.5~10 N.