Aluminizing for enhanced oxidation resistance of ductile refractory high-entropy alloys
Artikel i vetenskaplig tidskrift, 2018

Refractory high-entropy alloys (RHEAs) emerge as promising candidate materials for ultrahigh-temperature applications. One critical issue to solve for RHEAs is their balanced oxidation resistance and mechanical properties, mainly room-temperature ductility for the latter. Recently, it was found that existing ductile RHEAs are subject to catastrophic accelerated oxidation, also known as pesting. In this work, both alloying and surface coating, are applied to enhance the oxidation resistance of ductile RHEAs, with the focus on surface coating using the pack cementation method and more specifically, aluminizing. The oxidation resistance of two RHEAs, Hf0.5Nb0.5Ta0.5Ti1.5Zr, one recently identified ductile RHEA which pests in the temperature range of 600–1000 °C, and Al0.5Cr0.25Nb0.5Ta0.5Ti1.5, the newly designed ductile RHEA which does not pest but embrittles after oxidation, are studied after aluminizing at 900 °C using three different pack components. Aluminizing, if using the appropriate pack cementation parameters, can avoid pesting in Hf0.5Nb0.5Ta0.5Ti1.5Zr and alleviate the oxidation induced embrittlement in Al0.5Cr0.25Nb0.5Ta0.5Ti1.5, and holds the promise for further improving the RHEAs as potential ultrahigh-temperature materials.

Aluminizing

Coating

Pack cementation

Oxidation resistance

Refractory high-entropy alloys

Författare

Saad Ahmed Sheikh

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Lu Gan

National Institute for Materials Science

Waseda University

Te Kang Tsao

Waseda University

Hideyuki Murakami

Waseda University

National Institute for Materials Science

Samrand Shafeie

Uppsala universitet

Sheng Guo

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Intermetallics

0966-9795 (ISSN)

Vol. 103 40-51

Ämneskategorier

Keramteknik

Bearbetnings-, yt- och fogningsteknik

Annan kemi

DOI

10.1016/j.intermet.2018.10.004

Mer information

Senast uppdaterat

2018-12-07