High temperature oxidation of powder metallurgy two-phase Cu-Cr alloys under low oxygen pressure

来源期刊：中国有色金属学报(英文版)2000年第3期

论文作者：付广艳 牛焱 吴维tao

文章页码：353 - 357

Key words：two-phase Cu-Cr alloys; oxidation; low oxygen pressure

Abstract: The oxidation of two-phase Cu-Cr alloys containing 25% and 50% Cr prepared by powder metallurgy (PM) with a rather uniform two-phase microstructure has been studied at 700~900℃under oxygen pressure below the stability of the copper oxides. The two PM alloys oxidized very slowly and formed only external Cr₂O₃scales rather than undergoing an internal oxidation of chromium. This result is attributed mainly to a supply of chromium from the small Cr-rich particles dispersed within the Cu-rich phase. The oxidation kinetics of the two PM Cu-Cr alloys approximately followed the parabolic rate law. The scaling rates are of the same order as those measured for pure chromium under the same oxygen pressure, but smaller than those for the alloys of similar composition prepared by normal arc melting techniques, whose compositions were largely non-uniform. The results are interpreted in terms of the two-phase nature of these alloys.