中文摘要：

研究了二元cu—Cr合金Cu-0．5Cr；Cu-7．0CrCu-15．0Cr（原子分数，％）在700和800℃空气中的高温氧化行为．合金的氧化动力学基本遵循抛物线规律，其中Cu-0．5Cr合金的氧化近似于纯cu的氧化行为，氧化产物主要为Cu的氧化物，Cr2O3颗粒弥散分布于氧化膜内层靠近膜／基体界面；Cu-7．0Cr和Cu-15．0Cr氧化后外层形成CuO和Cu2O，内层为Cr2O3和Cu2O·Cr2O3混合氧化物，并含有部分未氧化的Cr颗粒．合金的氧化速率随Cr含量的增加而降低，并且β相尺寸减小也利于提高Cu—Cr合金的抗氧化能力．合金氧化膜结构和生长规律与合金的原始显微组织和口相分布状态有关．

英文摘要：

The ability to form external chromia scales on binary Cu-Cr alloys with very small mutual solubility of the two components is strongly increased either by increasing Cr content or by preparing alloys with a very small grain size. The purpose of the present work is to mainly examine the effect of Cr content and especially the influence of the size of the second phase. Equal channel angular pressing （ECAP） was carried out for the grain refinement because it can often provide significant inner deformation and very fine grains. The oxidation behavior of binary Cu-Cr alloys with different nominal Cr contents （Cu-0.5Cr, Cu-7.0Cr and Cu-15.0Cr, atomic fraction, %） was investigated in air at 700 and 800 ℃. At the same time, the oxidation of grain-refined Cu-7.0Cr alloy was compared with the same casting alloy with a normal grain size in order to further reveal the effect of the grain refinement on the oxidation. The oxidation kinetics of all alloys followed the parabolic law. Oxidation of Cu-0.5Cr alloy was basically similar to that of pure Cu and its scales are mainly composed of copper oxides containing a small amount of chromia particles dispersed in the inner layer, even close to the scale/alloy interface. The oxide scales formed on the Cu-7.0Cr and Cu-15.0Cr alloys were complex and were consisted in most cases of the outer layer of CuO and Cu：O plus inner layer of mixed oxides of chromia and double Cu-Cr oxide of Cu2O· Cr2O3, leaving unoxidized Cr particles surrounded by chromia in the scales. Cr depletion was also observed in the alloy. The grain-refined Cu-Cr alloy easily formed more chromia with much lower oxidation rate. The oxidation rate of Cu-Cr alloys decreased considerably with increasing Cr content and reduction in size of fl phase is favorable for improvement of anti-oxidation of Cu-Cr alloys. The result indicates that the alloy microstructure affects the oxidation behavior be- cause microcrystalline structures provide numerous diffusion path for reactive Cr component, shorter diffusion dista