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.