Revealing The Univariate Effect Of Structural Order On The Oxidation Of Ternary Alloys: Amorphous Vs. Crystalline Cu?Zr?Al Alloys

A comparative oxidation study of homogeneous amorphous and crystalline Cu28Zr51Al21 alloys is presented to reveal the univariate role of structural order on the oxidation behavior of multi-component alloys. Amorphous Cu?Zr?Al is confirmed much more oxidation-resistant than crystalline Cu?Zr?Al. Preferential oxidation of Zr and Al occurs in both alloys, resulting in an amorphous Zr?Al?O layer and a Cu-enriched region. Cu-enrichment in the crystalline alloy causes Cu9Al4 nanocrystals embedded in the oxide. However, the Cu-enriched region in the amorphous alloy remains amorphous because of its high glass-forming ability. Findings provide design strategies for achieving highly oxidation-resistant alloys.