Nanoindentation tests were performed to investigate the nano-scale plastic deformation in the Al_0.5CoCrCuFeNi high entropy alloys at room temperature (RT) and 200 °C, respectively. Serrated plastic flow, manifested as discrete bursts of plasticity on the load-displacement curve, was observed for both temperatures during the loading period, and its behavior and dependence on the temperature was analyzed from both the experimental and theoretical perspectives. The application of a mean-field theory indicated that the displacement bursts exhibited a temperature-dependent power-law distribution, and the universal exponents, κ and λ, were computed to be 1.5 and 0.04, respectively. With the use of the computed universal exponents, a critical annealing temperature for the slip-avalanche size distribution was estimated to be 1120 °C. Creep occurred during the nanoindentation holding period and exhibited very large stress exponent, implying that the dislocation glide-climb is the dominant mechanism. The creep simulations with a two-layer viscoplastic model further revealed that the deformation at a higher temperature (e.g., 200 °C) featured a greater and faster-growing plastic zone underneath the indenter, implying more pronounced dislocation activities.

进行了纳米压痕测试，以研究Al _0.5 CoCrCuFeNi高熵合金分别在室温（RT）和200°C下的纳米级塑性变形。锯齿状塑性流在载荷-位移曲线上表现为离散的塑性爆发，在加载期间观察到两种温度，并从实验和理论角度分析了其行为和对温度的依赖性。平均场理论的应用表明，位移爆发呈现出随温度变化的幂律分布，并且通用指数κ和λ分别计算为1.5和0.04。使用计算的通用指数，估计滑移雪崩尺寸分布的临界退火温度为1120°C。蠕变发生在纳米压痕保持期间，并表现出非常大的应力指数，这表明位错滑移-爬升是主要的机制。用两层粘塑性模型进行的蠕变模拟进一步表明，在较高温度（例如200°C）下的变形在压头下方具有更大且生长更快的塑性区，这意味着位错活动更加明显。