This paper describes the wear behavior, mild-to-severe wear transition (MSWT), analysis of microstructure and property underneath the wear surface for an Mg-10.1Gd-1.4Y-0.4Zr alloy within 0.2–4.0 m s⁻¹ under dry sliding condition. The volumetric wear rate was plotted against applied load at each experimental speed. The worn surfaces were examined by SEM and EDS techniques, from which the wear mechanisms were identified, and they were used to draw a wear mechanism transition map with mild and severe wear regions. The results reveal that there exists a turning point on the wear rate-load curve under each sliding speed, which actually corresponds to MSWT. Two different types of MSWT are found in different speed ranges. The first one is controlled by a severe oxidation wear, and it operates within 0.2–0.5 m s⁻¹, while the second one is controlled by a severe plastic deformation (SPD) wear, and it works within 0.8–4.0 m s⁻¹. An analysis of microstructure and property underneath the worn surface proves that the mechanism for the second type of MSWT is the dynamic recrystallization (DRX) induced softening of surface material. With the help of DRX dynamics theory of metals, the critical surface DRX temperatures for MSWTs within 0.8–4.0 m s⁻¹ are estimated, and from which the transition loads are evaluated according to a simplified modeling for MSWT load. There is a good agreement between the calculated and measured transition loads, indicating that SPD-controlled MSWT follows contact surface DRX temperature criterion.

本文描述了 Mg-10.1Gd-1.4Y-0.4Zr 合金在干滑动下0.2-4.0 ms ^-1的磨损行为、轻度到重度磨损转变 (MSWT)、磨损表面下的微观结构和性能分析状况。在每个实验速度下，将体积磨损率与施加的载荷作图。通过SEM和EDS技术检查磨损表面，从中识别磨损机制，并使用它们绘制具有轻度和重度磨损区域的磨损机制过渡图。结果表明，在每个滑动速度下，磨损率-载荷曲线存在一个转折点，实际上对应于MSWT。在不同的速度范围内发现了两种不同类型的 MSWT。第一个由严重的氧化磨损控制，它在 0.2-0.5 ms 内运行^-1，而第二个由严重的塑性变形 (SPD) 磨损控制，它在 0.8-4.0 ms ^{-1 内工作}。磨损表面下的微观结构和性能分析证明，第二种 MSWT 的机制是动态再结晶 (DRX) 诱导表面材料的软化。借助金属的 DRX 动力学理论，估计MSWT 的临界表面 DRX 温度在 0.8-4.0 ms ^-1内，并根据MSWT载荷的简化建模从中评估过渡载荷。计算和测量的过渡载荷之间有很好的一致性，表明 SPD 控制的 MSWT 遵循接触表面 DRX 温度标准。