Tribocorrosion Behavior of CoCrNi Medium Entropy Alloy in Simulated Seawater

Abstract

Understanding the fundamental behaviors of tribocorrosion for metals is critical for their possible application in seawater. For the recently emerging medium entropy alloys (MEAs), while mechanical wear and corrosion phenomena have been established, such experimental exploration is still lacking regarding the tribocorrosion behavior. In this work, the tribocorrosion behavior of CoCrNi MEA was investigated on a reciprocating sliding friction testing machine. Although a significant increase of current density formed due to sliding, CoCrNi exhibits superior passivity when compared with 316L and Inconel 600. In addition, the total tribocorrosion volume loss increases with positive shifting of the applied potential for CoCrNi. Specifically, the total material loss at an applied potential more positive than the pitting potential is one order in magnitude larger than that under pure mechanical wear, confirming the synergy between wear and corrosion. The generated pits on the worn surface became the preferred locations of wear and tear, leading to accelerated materials’ loss rate. Through detecting the morphologies of the contact surfaces, the features of abrasive wear, adhesive wear, delamination, and plastic deformation were revealed for CoCrNi during tribocorrosion at different potentials.

Characterisation of tensile deformation behaviour of Fe–25Cr–35Ni-based alloy at high temperature

“…Fe-25Cr-35Ni-based alloy undergoes dynamic recrystallisation (DRX) during high temperature tensile deformation. At small Z value (high tensile temperature and low strain rate), the DRX softening mechanism is easy to carry out [47]. When tensile deformation is carried out at high strain rate (a large Z value), the sliding time of dislocation is insufficient, and the DRX is difficult to achieve.…”

A Fresh Perspective on Medium Entropy Alloys Applications as Coating and Coating Substrate

“…Regarding the corrosion resistance, when the CoCrNi MEA and the CrMnFeCoNi HEA were analyzed comparatively in 0.1 M H2SO4 and 0.1 M NaCl, the MEA showed superior corrosion resistance [38]. Due to this behavior, the alloy could be used in ocean engineering structures as it was also shown that it exhibits superior passivity compared with 316L and Inconel 600 [39]. The CoCrNi alloy was also tested under an ultrahigh explosive loading rate to evaluate its suitability as a shaped charge liner, which could be used in many industries, A Fresh Perspective on Medium Entropy Alloys Applications as Coatings or Coating Substrate 37 such as oil, mining and construction.…”

Effect of Dissolved Oxygen Content on Tribo-Corrosion Behavior of Monel 400 Alloy in Seawater

“…In addition, marine equipment contains many friction parts, including sea pumps, transmission shafts, etc. This means that metal materials will not only suffer corrosion but also suffer wear, and they will even suffer coupling damage of corrosion and wear (tribo-corrosion) in the marine environment [7][8][9]. The damage of metal materials greatly affects the safety and stability of marine equipment.…”