Surface Science and Tribology Lab, Department of Mechanical Engineering, Shiv Nadar University, Gautam Budh Nagar, India.
Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA.
Ultrason Sonochem. 2018 Mar;41:252-260. doi: 10.1016/j.ultsonch.2017.09.044. Epub 2017 Sep 28.
Cavitation erosion and corrosion of structural materials are serious concerns for marine and offshore industries. Durability and performance of marine components are severely impaired due to degradation from erosion and corrosion. Utilization of advanced structural materials can play a vital role in limiting such degradation. High entropy alloys (HEAs) are a relatively new class of advanced structural materials with exceptional properties. In the present work, we report on the cavitation erosion behavior of AlCoCrFeNi HEA in two different media: distilled water with and without 3.5wt% NaCl. For comparison, conventionally used stainless steel SS316L was also evaluated in identical test conditions. Despite lower hardness and yield strength, the HEA showed significantly longer incubation period and lower erosion-corrosion rate (nearly 1/4th) compared to SS316L steel. Enhanced erosion resistance of HEA was attributed to its high work-hardening behavior and stable passivation film on the surface. The AlCoCrFeNi HEA showed lower corrosion current density, high pitting resistance and protection potential compared to SS316L steel. Further, HEA showed no evidence of intergranular corrosion likely due to the absence of secondary precipitates. Although, the degradation mechanisms (formation of pits and fatigue cracks) were similar for both the materials, the damage severity was found to be much higher for SS316L steel compared to HEA.
空蚀和结构材料的腐蚀是海洋和近海工业的严重问题。由于腐蚀和空蚀导致的降解，海洋部件的耐久性和性能严重受损。先进结构材料的利用可以在限制这种降解方面发挥重要作用。高熵合金（HEA）是一种具有优异性能的新型先进结构材料。在本工作中，我们报告了 AlCoCrFeNi HEA 在两种不同介质中的空蚀行为：蒸馏水和含 3.5wt%NaCl 的蒸馏水。为了进行比较，还在相同的试验条件下评估了常用的不锈钢 SS316L。尽管 HEA 的硬度和屈服强度较低，但与 SS316L 钢相比，HEA 表现出明显更长的潜伏期和更低的侵蚀-腐蚀速率（接近 1/4）。HEA 的耐侵蚀性增强归因于其高加工硬化行为和表面稳定的钝化膜。与 SS316L 钢相比，AlCoCrFeNi HEA 表现出较低的腐蚀电流密度、高耐点蚀性和保护电位。此外，由于不存在二次析出物，HEA 没有表现出晶间腐蚀的迹象。尽管两种材料的降解机制（点蚀和疲劳裂纹的形成）相似，但与 HEA 相比，SS316L 钢的损伤严重程度要高得多。
