大气环境空间用铜基摩擦材料摩擦学行为及可靠性寿命研究

Tribological Behaviors and Reliability Life of Cu-Based Sintered Materials for Space Applications in Air

本文中采用自主开发的空间摩擦试验机,模拟空间用摩擦副大负荷服役条件(400 N)进行摩擦循环试验,考察了大气环境下空间用铜基粉末冶金摩擦材料的摩擦磨损特性,探讨了摩擦副的可靠性寿命并揭示了其摩擦磨损机理.研究结果表明:摩擦副在模拟大负荷摩擦循环试验中,可划成三个阶段:第一阶段属可靠性使用阶段,摩擦系数合适而稳定,磨损机理以磨粒磨损和氧化磨损为主;第二阶段,摩擦特性发生失稳,摩擦系数周期性变化,磨损机理以氧化磨损为主,接触疲劳磨损为辅;第三阶段,摩擦系数波动较大,磨损机理转变为严重的接触疲劳磨损和氧化磨损,材料失效.

In the present investigation, the friction and wear characteristics of Cu-based powder metallurgy friction materials were evaluated on a space friction testing machine at high load in air. The reliability life and wear mechanisms of friction materials were investigated and revealed. The experimental results show that there were three stages in the friction process. During the first stage, the friction pair presented reliable performances, and its friction coefficient was stable. In the first stage, the abrasive wear and oxidation wear were the dominant wear mechanism.The friction properties became unstable, and the friction coefficient increased cyclically in the second stage.The dominant wear mechanism turned to be oxidation wear, accompanied by mild contact fatigue wear. In the third stage, the friction coefficient fluctuated greatly, and the dominant wear mechanism transformed to be severe fatigue wear and oxidation wear, leading to the material failure.