Effect of aging precipitation strengthening on friction and wear behavior of GW83 magnesium alloy

In order to study the effect of aging strengthening on the wear mechanism and frictional deformation behavior of rare earth magnesium alloys, GW83 (Mg-8Gd-3Y-0.5Zr, mass fraction/%) rare earth magnesium alloy was prepared by extrusion process. The electronic universal testing machine was used to evaluate the alloy's mechanical properties.The optical microscope (OM), scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to examine the alloy's microstructure.The ball-on-disc dry sliding friction testing machine was used to examine the wear resistance. The results show that after aging treatment (T5), a large amount of β′ precipitated phases are precipitated in the alloy. The hardness and tensile strength of the alloy are 124.1HV and 420.31 MPa, respectively, which are significantly higher than those in the extruded state (O state). As the load increases, the friction coefficient of the alloy decreases and the wear rate increases. Aging treatment can significantly improve the wear resistance of GW83 alloy, which is related to changes in wear mechanism and degree of friction deformation. Under a load of 5-10 N, the main wear mechanisms of both samples are abrasion, oxidation, and adhesive wear. When the load increases to 20 N, the main wear mechanism of the O state sample changes to delamination wear, while the transition load of the T5 sample is 80 N. T5 heat treatment significantly reduces the degree of surface metal deformation and deformation layer thickness caused by friction, thereby reducing the generation of friction cracks.