Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (26권5호 235-244)

High temperature oxidation behavior of Ti-33.8wt% Al intermetallic compounds

Ti-33.8wt% Al 금속간 화합물의 고온 산화거동

최송천;조현준;이동복;

성균관대학교 금속공학과;

Abstract

The oxidation behavior of a two-phase(Ti3Al+TiAl) intermetallic compound, Ti-33.8wt%Al, has been in-vestigated in air at 800, 900 and $^1000{circ}C$. Though the isothermal oxidation behavior followed a parabolic law up to 100$0^{circ}C$ indicating that protective oxide scales were formed, the cyclic oxidation behavior followed a lin-ear law in the entire temperature range tested because flaky or stratified scales were usually spalled from the surface during cooling. During oxidation at 80$0^{circ}C$, the alloy showed excellent oxidation resistance because continuous protective Al2O3 films were formed on the outermost surface of the alloy. However, above $900^{circ}C$, the oxidation resistance of the alloy was decreased gradually because relatively non-protective TiO2 scales as well as some of Al2O3 scales were formed on the outer oxide scale. The oxidation mechanism of the alloy at different temperature was proposed.

Keywords