Isothermal High Temperature Oxidation of Cantor's-based MC-reinforced HEAs versus their Mn and Cr Contents
Résumé
High Entropy Alloys / the equimolar CoNiFeMnCr composition (Cantor)
• Adding MC carbides ® enhancement of the H.T. mechanical resistance
• Unfortunately: bad oxidation behavior at 1000°C and beyond
– Fast mass gains; Thick oxides scales after less than 100 hours
– Only minor role of chromium; Oxide scales involving Mn more than Cr
• Possible way for improving resistance against oxidation: ¯ Mn and Cr
• THIS WORK: investigation of H.T. oxidation of new alloys with less Mn
and more Cr
• Decreasing Mn and increasing Cr indisputably improve the H.T. oxidation behavior
• The new oxidation resistances are still below the Ni–30Cr’s one
• MC carbides degrade oxidation resistance (especially HfC)
• Oxides scales are multi–constituted and too porous to be really protective
->Removing all Mn and testing CoNiFeCr + MC alloys
(alloys at the frontier between Cantor’s alloy and Co-based/Ni-based alloys)
or
->Replacing Mn by M’ and testing CoNiFeM’Cr + MC alloys
(e.g. starting from the already existing CoNiFeCuCr HEAs)
Origine : Fichiers produits par l'(les) auteur(s)