The suitability of determining the strain rate sensitivity (SRS) of the CoCrFeMnNi high-entropy alloy (HEA) by small punch (SP) testing has been assessed at displacement rates ranging from 0.2 to 2 mm∙min⁻¹. The stress was found to increase as the displacement rate was raised from 0.2 to 2 mm∙min⁻¹, whereas the plastic strain distributions were similar in all cases. However, for a higher displacement rate of 10 mm∙min⁻¹, the sample was found to exhibit a drop in strength and ductility attributed to casting defects. The strain-rate sensitivity exponent (m) was found to be 0.1387 whilst the Finite Element Analysis (FEA) simulations predicted a slightly smaller value of 0.1313. This latter value is closer to m = 0.091 obtained from nanoindentation strain rate jump tests since the results are insensitive to the presence of small casting defects. The relationship between the experimental and the empirically derived predicted properties from the SP tests revealed a high level of agreement for maximum stress properties. The properties predicted at 2 mm∙min⁻¹ (R² = 0.96) offered a stronger fit than at 0.5 mm∙min⁻¹ (R² = 0.92).

通过小冲头 (SP) 测试确定 CoCrFeMnNi 高熵合金 (HEA) 的应变率灵敏度 (SRS) 的适用性已经在 0.2 至 2 mm∙min ⁻¹的位移速率范围内进行了评估。当位移速率从 0.2 增加到 2 mm∙min ^-1时，发现应力增加，而塑性应变分布在所有情况下都相似。然而，对于 10 mm∙min ^-1的更高位移速率，发现样品表现出归因于铸造缺陷的强度和延展性下降。发现应变率灵敏度指数( m ) 为 0.1387，而有限元分析 (FEA) 模拟预测的值略小，为 0.1313。后一个值更接近于m = 0.091 从纳米压痕应变率跳跃测试中获得，因为结果对小铸造缺陷的存在不敏感。SP 测试的实验和经验推导的预测特性之间的关系揭示了最大应力特性的高度一致性。^{在 2 mm∙min −1} (R ² = 0.96)时预测的特性比在 0.5 mm∙min ⁻¹ (R ² = 0.92)时提供更强的拟合。