Cavitation erosion of the CoCrFeNi high entropy alloy having elemental segregation

作者：Hoi, K. C.; Lei, W. H.; Liu, Yining; Shek, C. H.; Ferreira, Jessica T. G.; Cortez, Nicete F. T.; Kwok, C. T.; Sun, Y. F.; Cristino, Valentino A. M.; Lo, K. H.^*

来源：Wear, 2023, 530: 204990.

DOI：10.1016/j.wear.2023.204990

• MECHANICAL-PROPERTIES
• CORROSION BEHAVIOR
• 304-STAINLESS-STEEL
• MARTENSITE
• RESISTANCE
• EVOLUTION

The cavitation-erosion (CE) damage features and a microstructural peculiarity of the CoCrFeNi high entropy alloy (HEA) are presented in this paper. While this HEA is theoretically predicted and often experimentally demonstrated to be a single-phase solid solution, noticeable elemental segregation has been observed in both the interdendritic regions and dendrite interiors in this study. This segregation causes a subtle reduction of lattice parameter, and the interdendritic segregated regions are frequently CE damage initiation sites. In the dendrite interiors, oxygen-rich particles with elemental segregation as their wrappings and the small speckles of elemental segregated regions show different CE damage features. In the dendrite interiors, CE-induced martensite formation is negligibly, and slip lines and their intersections are CE damage initiation sites. While a few CoCrFeNi-based HEAs have been shown to be CE-resistant in the literature, the CE resistance of the CoCrFeNi base itself is not high.

• 单位
  郑州大学