High entropy alloys (HEAs) are expected to be applied at elevated temperatures. However, the tribological properties of the HEAs in a wide temperature range have not been studied systemically, especially at high temperatures. In this paper, the micro-hardness as well as the tribological properties of Al_0.2Co_1.5CrFeNi_1.5Ti_0.5+xC_x (x = 0, 1.0 and 2.0) HEAs from 25°C to 800°C was investigated and compared with Inconel 718 superalloy. The results showed that the solid solution strengthening effect of the HEAs and the dispersion strengthening effect of in situ generated TiC resulted in a significantly higher high temperature microhardness of the carbon-doped HEAs than that of the Inconel 718. The friction coefficient of the HEAs increased with increasing carbon content at same temperature, but it decreased as the temperature increased. The wear resistance of carbon doped HEAs were superior than that of Inconel 718 and carbon-free HEAs from 25 to 800 °C. Below 600 °C, the wear rate of the HEAs which decreased monotonously with increasing carbon content was in the range of (0.31-12.56) × 10^-5 mm³ N^-1∙m^-1, but above 600 °C, the wear rate of the HEAs was proportion to carbon content within (2.64-23.90) × 10^-6 mm³ N^-1∙m^-1. The excellent high-temperature wear resistance of the HEAs was attributed to the synergistic effect of the good high temperature softening resistance and a nano-oxidized glaze layer with superior mechanical properties on the worn surface.

预计高熵合金 (HEA) 将在高温下应用。然而，尚未系统地研究 HEA 在较宽温度范围内的摩擦学特性，尤其是在高温下。本文研究了 Al _0.2 Co _1.5 CrFeNi _1.5 Ti _0.5+x C _x的显微硬度和摩擦学性能(x = 0、1.0 和 2.0) 研究了 25°C 至 800°C 的 HEA，并与 Inconel 718 高温合金进行了比较。结果表明，HEAs 的固溶强化作用和原位生成 TiC 的弥散强化作用导致碳掺杂 HEAs 的高温显微硬度显着高于 Inconel 718。HEAs 的摩擦系数增加同温度下含碳量增加，但随温度升高而降低。在 25 至 800 °C 范围内，掺碳 HEA 的耐磨性优于 Inconel 718 和无碳 HEA。在600℃以下，随着碳含量的增加单调下降的HEAs的磨损率在（0.31-12.56）×10 ^-5  mm ³  N ^{-1 范围内}∙m ^-1，但在 600 °C 以上，HEAs 的磨损率与碳含量成正比，在 (2.64-23.90) × 10 ^-6  mm ³  N ^-1 ∙m ^{-1 内}。HEAs优异的高温耐磨性归因于良好的耐高温软化性和磨损表面具有优异机械性能的纳米氧化釉层的协同作用。