|About this Abstract
||1st World Congress on High Entropy Alloys (HEA 2019)
||High Entropy Alloys 2019
||The Origins of Excellent Passivity in Single Phase High Entropy Alloys
||Angela Y. Gerard, Kang Wang, Pin Lu, Stephen McDonnell, Wofgang Windl, Dan Schreiber, Bi-Cheng Zhou, Sarita Sahu, Tianshu Li, Gerald S Frankel, John R Scully
|On-Site Speaker (Planned)
||John R Scully
Studies of passivation of several high entropy alloys (HEAs) were conducted in corrosive aqueous environments such as NaCl and H2SO4 solution. A single phase NiCrFeRuMoW HEA in the solutionized condition was spontaneously passive even in concentrated HCl solution. Good passivity at anodic potentials was traced to the formation of a disordered non-stoichiometric solid solution oxide containing all alloying elements in an oxidized state. A series of single phase NiFeMnCoCr HEAs with Cr composition varying from 6 to 22%, balanced by changes in the Mn and Co contents, was also investigated. Lower passive current densities were observed compared to the binary alloys at equivalent Cr contents. Passive films consisted of mainly oxidized Ni, Cr, and Fe with very little Co and Mn. Both thermodynamic and kinetic influences were considered to develop a better understanding of factors governing these oxide film compositions and structures.