High entropy alloys represent a new paradigm of structural alloy design consisting of (near) equal proportions of constituent elements resulting in a number of attractive properties. In particular, eutectic high entropy alloys offer a remarkable combination of high strength and good ductility from the synergistic contribution of each phase in the eutectic, thereby circumventing the strength-ductility trade-off in conventional structural materials. In the present study, wear and corrosion behavior were evaluated for the AlCoCrFeNi_2.1 eutectic high entropy alloy consisting of BCC (B2), and FCC (L1₂) lamellae. A transition from adhesive to oxidative wear was observed in reciprocating wear analysis. The L1₂ phase with lower hardness preferentially deformed during the wear test. The ratio of hardness to modulus was almost two times higher for the B2 phase as compared to L1₂. The overall corrosion resistance of the eutectic high entropy alloy was comparable to 304 stainless steel in 3.5 wt% NaCl solution. However, detailed microscopy revealed preferential dissolution of the B2 phase. Phase-specific scanning kelvin probe analysis showed relatively higher electropositivity for the B2 phase as compared with L1₂, supporting the selective corrosion and higher coefficient of friction of B2.

高熵合金代表了一种结构合金设计的新范式，它由（接近）相等比例的组成元素组成，从而产生了许多吸引人的性能。特别是，共晶高熵合金由于共晶各相的协同作用而提供了高强度和良好延展性的显着组合，从而避免了常规结构材料中强度-延展性的折衷。在本研究中，对由BCC（B2）和FCC（L1 ₂）薄片组成的AlCoCrFeNi _2.1共晶高熵合金的磨损和腐蚀行为进行了评估。在往复磨损分析中观察到了从粘合剂到氧化磨损的过渡。L1 ₂硬度较低的相在磨损测试过程中会优先变形。与L1 ₂相比，B2相的硬度与模量之比几乎高出两倍。共晶高熵合金的整体耐腐蚀性在3.5 wt％NaCl溶液中与304不锈钢相当。但是，详细的显微镜检查显示出B2相的优先溶解。相特异性扫描开尔文探针分析显示，与L1 ₂相比，B2相具有相对较高的正电性，支持B2的选择性腐蚀和较高的摩擦系数。