两种不同成形工艺下AZ91D镁合金滑动磨损行为研究

采用UMT-2MT摩擦试验机考察了触变成形和传统金属型铸造AZ91D镁合金滑动磨损行为。其摩擦条件是干摩擦往复式、球面一平面接触、与GCr15钢作对偶；研究了载荷和频率对镁合金摩擦磨损性能的影响。分析了其摩擦系数变化和磨痕形貌，并探讨了其磨损机理。研究结果表明，不论何种工艺方法的平均摩擦系数都在0．22～0．40之间，随着频率的增加二者的平均摩擦系数都减小,触变成形的耐磨性比金属型铸造的好；二者的磨损机制相似，在较低载荷下，镁合金的磨损机制为氧化磨损，随着载荷的增大，磨损机制为磨粒磨损、剥层磨损。

Sliding Wear Behavior of AZ91D Magnesium Alloy by Two Different Methods

The sliding wear behaviors of thixoforming(ThF)AZ91D magnesium alloy in a plane-on-ball configuration and reciprocating dry friction were investigated,using steel GCr15 as the counterpoint,compared with traditional casting with metal mold(TCMM).The effects of the normal load and frequency on the friction and wear properties of the Mg alloys were studied,the worn surfaces and the variety of friction coefficients were analyzed.The mechanism of sliding wear was discussed.The results show the sliding wear behaviors of the Mg alloys in two different molding methods are closely dependent on the testing parameters such as frequency and friction coefficients.The average friction coefficients in both types of tests fall into the range of 0.22~0.40,and decrease with frequency increasing.The ThF showes better sliding wear resistance than the TCMM.The Mg alloys have the same sliding wear mechanisms as oxidation wear under lower load and surface fatigue wear and abrasive wear with the load increasing.