连续制动条件下泡沫陶瓷/金属双连续相复合材料的摩擦磨损性能EI北大核心CSCD

为解决履带式特种车辆机械制动器过热失效问题,采用挤压铸造法制备SiC/Cu和SiC/Fe双连续相复合材料,研究两种材料在连续紧急制动工况和连续高温制动工况下的摩擦磨损性能。结合扫描电子显微镜(SEM)、X射线能谱分析(EDS)、三维形貌仪等手段分析摩擦因数、温度和磨损率的变化规律,揭示相应的磨损机理。结果表明:在连续紧急制动实验中,接触表面经历了摩擦膜形成和层间断裂过程,摩擦因数随接合次数增加略微下降,并趋于稳定。在前40次接合中,SiC/Cu和SiC/Fe摩擦副的磨损率整体下降。在40~60次接合中,SiC/Cu摩擦副黏着磨损、氧化磨损和疲劳磨损加剧,磨损率升高。而SiC/Fe摩擦副以磨粒磨损为主,磨损率较低。在连续高温制动实验中,摩擦因数在前6次接合中逐渐升高,制动时间逐渐缩短。在第6次接合后,摩擦副边缘区域出现的黏着磨损和疲劳磨损导致力矩下降,摩擦因数和制动时间均呈先降后升趋势。连续高温制动过程中以严重的黏着磨损为主,SiC/Cu和SiC/Fe摩擦副的磨损率均随接合次数增加而升高。

Friction and wear properties of foam ceramic/metal bi-continuous phase composites under continuous braking conditions

In order to solve the overheating failure problem of mechanical brakes of special tracked vehicles, SiC/Cu and SiC/Fe bi-continuous composites were prepared by squeeze casting method. The friction and wear properties of the two composites under continuous emergency braking and continuous high temperature braking conditions were studied. The variation of friction coefficient, temperature and wear rate was analysed by means of scanning electron microscopy (SEM), X-ray energy dispersive spectrometry (EDS) and 3D profiler, and the wear mechanism was described. The results show that in the continuous emergency braking test, the contact surface experiences the process of tribo-film formation and interlayer fracture.Friction coefficient decreases slightly with the increase of joining times and tends to be stable. In the first 40 joining, the wear rates of SiC/Cu and SiC/Fe friction pairs decrease overall. During 40-60 joining, the adhesion wear, oxidation wear and fatigue wear of the SiC/Cu friction pair are aggravated, and the wear rate increases, while the wear rate of the SiC/Fe friction pair is mainly abrasive wear, and the wear rate is low. In the continuous high temperature braking test, the friction coefficient increases gradually and the braking time decreases gradually in the first six joining. After the sixth joining, the adhesion wear and fatigue wear in the edge area of the friction pair result in the decrease of the torque, and the friction coefficient and braking time both show a trend of decrease at first and then increase. In the process of continuous high temperature braking, severe adhesive wear is the main factor. The wear rates of SiC/Cu and SiC/Fe friction pairs increase with the increase of joining times.