碳化硅/碳化钨硬面密封摩擦副的摩擦磨损性能和机理研究

实验研究了干摩擦和水润滑条件下, 常压固相烧结碳化硅陶瓷(SSiC)及常压液相烧结碳化硅陶瓷(LPSiC)分别与碳化钨(WC)组成的硬面配对摩擦副的滑动摩擦磨损性能。在干摩擦条件下, 与LPSiC/WC摩擦副相比, SSiC陶瓷由于具有更大的晶粒尺寸和硬度, 导致SSiC/WC摩擦副具有更大的摩擦系数和更小的磨损量。磨损区域的SEM形貌结合面扫描分析、微区XRD分析结果表明: 微犁沟和微断裂导致SiC陶瓷的磨损, 疲劳损伤导致WC材料的磨损, 而摩擦过程产生的摩擦热导致磨出的WC颗粒氧化成无定型WO₃。在水润滑条件下, 与SSiC/WC摩擦副相比, LPSiC/WC摩擦副具有更大的摩擦系数和更低的磨损率。在干摩擦和水润滑条件下, 与SiC陶瓷作为动摩擦副配对相比, SiC陶瓷作为固定摩擦副的摩擦配对具有更小的摩擦系数和质量损失。

Friction-wear Properties and Mechanism of Hard Facing Pairs of SiC and WC

Sliding friction-wear properties of pressurelessly solid-state-sintered silicon carbide ceramics (SSiC) and liquid-phase-sintered SiC ceramics (LPSiC) pairing with tungsten carbide (WC) were researched under the frictions with or without lubrication. Under dry friction, as compared to LPSiC/WC pairs, SSiC/WC pairs have higher friction coefficient (μ) and less mass loss (Δm) due to SSiC ceramics have larger particle size and higher hardness. The surface topography of worn area was detected by SEM companying with elements mapping and micro-area XRD technology. The micro plough cut and micro fracture led to the wear of SiC ceramics. Its fatigue damage led to the wear of WC materials. The grinding-out WC grains were oxidized to amorphous WO₃ phase due to the friction heat generated in the friction. Under the wet friction with water as lubrication, as compared to SSiC/WC pairs, LPSiC/WC pairs have higher friction coefficient and less mass losses. Whether under dry friction or wet friction, the pairs with SiC ceramics as the fixed materials have lower μ and Δm than those with SiC ceramics as the rotated materials.