压铸镁合金AZ91D摩擦磨损性能的研究

采用MM-200型磨损试验机，研究了干滑动摩擦条件下载荷和磨损时间对液态压铸成形镁合金AZ91D摩擦磨损性能的影响，借助扫描电镜探讨了材料的磨损机理。试验结果表明：当滑动速率为0．618m／s、载荷为20～250N时，液态压铸镁合金的磨损速率和摩擦因数均随着载荷的增大而增大，当载荷增大到250N之后，试样的磨损质量反而减小；随着磨损时间的增加，压铸镁合金的磨损质量损失呈线性比例增大，其摩擦因数在0．220～0．235范围内波动；T4和T6热处理对高载荷下镁合金材料的耐磨性能有一定的影响；随着载荷的增大，各种状态下镁合金材料的磨损机制均发生了由氧化磨损、剥层磨损、粘着磨损到熔化磨损的转变。

Study on Friction and Wear Characteristics of Die Casting Magnesium Alloy AZ91D

The dry sliding friction and wear characteristics of die casting magnesium alloy AZ91D, which was in as-cast,T4 heat treatment and T6 heat treatment state, were studied at different load and wear times by using an MM-200 abrasion tester. The scanning electron microscope was used for the analysis of sample worn surface configuration and determination of wear mechanism. The results show that when the rotating speed is 0. 618 m/s and the load varies in 20 to 250N respectively, the wear rate and friction coefficient of magnesium alloy enhances with raising the load, and the wear loss mass reduces instead when the load arrives at 250N. The wear loss of Mg alloy enhances in linearity proportion with the load, while the friction coefficient of Mg alloy is varied in 0.22 to 0. 235. T4 and T6 heat treatment have a certain effects on the friction and wear characteristics of Mg alloy at high load state. The magnesium alloys in different states have the same wear mechanism with the load raises, which includes oxidation wear, delamination wear, adhesion wear and melted wear.