Cavitation erosion remains the primary cause of material degradation in fluid machinery components operating at high speed. Micro-jets/shock waves caused by implosion of bubbles on material surface results in significant material loss and premature failure of the components. The presence of corrosive medium further exuberates this effect, causing rapid degradation. Here, we demonstrate a novel pathway to control cavitation erosion-corrosion by tailoring the surface properties using submerged friction stir processing (FSP), a severe plastic deformation process. FSP parameters were varied over wide range of strain-rates to generate tailored microstructures. High strain-rate processing resulted in nearly single phase fine grained structure while low strain-rate processing resulted in phase transformation in addition to grain refinement. As-received and processed samples were subjected to ultrasonic cavitation in distilled water as well as in corrosive environment of 3.5 % NaCl solution. Individual roles of cavitation erosion, corrosion and their synergistic effects were analyzed. Depending on the microstructure, processed samples showed nearly 4-6 times higher cavitation erosion resistance compared to as-received alloy. Superior cavitation erosion-corrosion resistance of processed samples was attributed to surface strengthening, higher strain-hardening ability and quick passivation kinetics. The results of current study could be potentially transformative in designing robust materials for hydro-dynamic applications.

空化腐蚀仍然是高速运转的流体机械部件中材料降解的主要原因。由气泡在材料表面内爆引起的微喷射/冲击波会导致大量材料损失和组件过早损坏。腐蚀性介质的存在进一步加剧了这种效应，导致快速降解。在这里，我们演示了一种通过使用淹没式摩擦搅拌工艺（FSP）（一种严重的塑性变形过程）来定制表面性能来控制空化侵蚀和腐蚀的新途径。FSP参数在很大的应变率范围内变化，以生成量身定制的微结构。高应变速率处理导致几乎单相细晶粒结构，而低应变速率处理除了晶粒细化之外还导致相变。在蒸馏水中以及在3.5％NaCl溶液的腐蚀性环境中，对接收和处理的样品进行超声空化。分析了空蚀，腐蚀及其协同作用的个体作用。取决于微观结构，加工后的样品显示出的抗空蚀性能比原合金高出近4-6倍。加工后的样品具有出色的抗气蚀腐蚀性能，这归因于表面强化，更高的应变硬化能力和快速钝化动力学。当前研究的结果可能在设计用于水动力应用的坚固材料方面具有潜在的变革性。分析了空蚀，腐蚀及其协同作用的个体作用。取决于微观结构，加工后的样品显示出的抗空蚀性能比原合金高出近4-6倍。加工后的样品具有出色的抗气蚀腐蚀性能，这归因于表面强化，更高的应变硬化能力和快速钝化动力学。当前研究的结果可能在设计用于水动力应用的坚固材料方面具有潜在的变革性。分析了空蚀，腐蚀及其协同作用的个体作用。取决于微观结构，加工后的样品显示出的抗空蚀性能比原合金高出近4-6倍。加工后的样品具有出色的抗气蚀腐蚀性能，这归因于表面强化，更高的应变硬化能力和快速钝化动力学。当前研究的结果可能在设计用于水动力应用的坚固材料方面具有潜在的变革性。更高的应变硬化能力和快速的钝化动力学。当前研究的结果可能在设计用于水动力应用的坚固材料方面具有潜在的变革性。更高的应变硬化能力和快速的钝化动力学。当前研究的结果可能在设计用于水动力应用的坚固材料方面具有潜在的变革性。