Effect of grain size on high-temperature oxidation behavior of Cu-80Ni alloy

来源期刊：中国有色金属学报(英文版)2003年第4期

论文作者：曹中秋 牛焱 曹丽杰 吴维tao

文章页码：907 - 911

Key words：copper-nickel alloy; Cu-80Ni alloy; single-phase; high-temperature oxidation

Abstract: The thermogravimetric analysis of binary Cu-80Ni alloys prepared respectively by conventional casting(CA) and mechanical alloying(MA) techniques and presenting widely different grain sizes was performed at 800℃ in air in order to study the effect of grain size change on the oxidation behavior of a solid solution alloy. The results show that the kinetic curves for the oxidation of the two alloys are complex and deviate from the parabolic rate law and usually are not composed of a single stage. Mixed scales were produced on the CACu-80Ni alloy surface, which consists of a mixture of copper and nickel oxides. However, oxide scale for MACu-80Ni alloy is mainly composed of a thick compact and continuous inner layer of nickel oxide. The reduction in the alloy grain size speeds up the diffusion of the more reactive component nickel from the alloy to alloy/oxide scale interface and completes the transition from a mixed scale to continuous scale of nickel oxide.