腐蚀介质下AZ91镁合金滑动摩擦磨损失效行为分析

Failure Behavior Analysis of Sliding Friction and Wear of AZ91 Magnesium Alloy under Corrosion Medium

利用滑动摩擦磨损试验分别研究了AZ91镁合金在干摩擦条件下和腐蚀介质环境下的滑动摩擦磨损失效行为,并结合腐蚀产物的分析结果,验证了腐蚀可加速磨损失效的进程。结果显示:在干摩擦条件下,AZ91镁合金的摩擦因数随载荷增大表现为先减小后增大,其主要磨损失效形式表现为磨粒磨损和氧化磨损;在腐蚀介质环境下,AZ91镁合金的摩擦因数随载荷增大表现为先减小后趋于平稳,且与干摩擦条件下相比稍有下降,主要是由于腐蚀介质加入后产生了润滑的效果,其主要磨损失效形式表现为磨粒磨损和氧化磨损,以及Cl-的侵蚀影响,失效较为严重;AZ91镁合金在腐蚀磨损后,其磨痕区周围出现了大量点蚀坑,且点蚀坑的数量明显多于磨痕区。

The failure behaviors of sliding friction and wear of AZ91 magnesium alloy under dry friction condition and corrosion medium environment are investigated by means of sliding friction and wear test.Combined with the analysis results of corrosion products,the process of wear failure accelerated by the corrosion is verified. The results show that under dry friction condition,the Coefficient Of Friction（ COF） of AZ91 magnesium alloy decreases first and then increases with the increase of load,and the main wear failure forms are abrasive wear and oxidation wear. In corrosion medium environment,the COF of AZ91 magnesium alloy decreases first and then tends to be stable with the increase of load,and compared with that under dry friction condition,the COF of AZ91 magnesium alloy decreases slightly. It is mainly due to the effect of lubrication caused by the addition of corrosion medium. The failure form is characterized by abrasive wear and oxidative wear,as well as the influence of Cl-erosion,and the failure is more serious. After the corrosion wear of AZ91 magnesium alloy,there are a lot of pits around the wear mark area,and the number of pits is more than the wear mark area.