河南科技大学 硕士学位论文 稀土微合金化Cu-Cr合金内氧化动力学及其性能研究 姓名：张金东 申请学位级别：硕士 专业：材料学 指导教师：刘勇 20091201 摘 要 I 论文题目：论文题目：稀土微合金化 Cu-Cr 合金内氧化动力学及其性能研究 专专 业：业：材料学 研研 究究 生：生：张金东 指导教师：指导教师：刘 勇 副教授 摘 要摘 要 弥散强化铜复合材料具有高导热率、高导电率和优良的高温强度、高温抗蠕 变性能、耐磨性能好等优点，广泛应用于机电、电子、宇航和原子能等领域内 氧化工艺已经成为弥散强化铜复合材料研究的焦点 本文采用包埋内氧化工艺，以 Cu-0.8Cr 合金实体为原料，加入不同含量 Ce，制备了 Cu-Cr2O3(RE)复合材料，并从热力学方面分析了 Cu-0.8Cr 合金表面 内氧化的可行性，建立了基于氧在 Cu-0.8Cr 合金基体中非稳扩散态条件下片状 试样和圆柱试样的内氧化动力学模型，以便对合金内氧化过程进行描述；分析了 稀土 Ce 对 Cu-0.8Cr 合金内氧化性能和显微组织的影响；研究了冷变形过程中稀 土 Ce 中对 Cu-Cr2O3复合材料组织和性能的影响。
研究结果表明： 1. Cu-Cr 合金发生内氧化的上限氧分压为： 2 Cu O ( 41065/29.94)PexpT=−+ 下限氧分压为： 2 Cr O ( 59912/17.73)PexpT=−+ 2. 基于氧在固态铜中进行非稳态扩散的 Cu-Cr 平板试样内氧化动力学方程 为： 2 OO OCr 4 0.6293 N D Xt NN =⋅ + Cu-Cr 合金圆柱试样内氧化动力学方程为: 222 OO 12212 Cr 41 ()ln( /) 23 N D rrrr rt N −−=⋅ 试验结果与两模型吻合较好 3. 随着内氧化时间的延长以及温度的提高，内氧化层厚度不断加深少量 Ce的加入加速了Cu-0.8Cr合金的内氧化进程Cu-0.8Cr-0.2Ce合金圆柱试样 河南科技大学硕士学位论文 II 950℃内氧化12h后，氧化层深度可达798μm 4. 稀土Ce的加入可提高合金的显微硬度、电导率及抗拉强度Cu-Cr合金 内氧化前显微硬度、电导率、抗拉强度分别为92HV、54.7%IACS、247MPa，添 加0.2%Ce的Cu-Cr合金，经12h内氧化后其显微硬度、电导率、抗拉强度分别 提高到128HV、80%IACS、400MPa。
5. 试样经内氧化后，随着变形量的增加其显微硬度、抗拉强度明显提高， 导电率有所降低当变形量为80%时，0.2%Ce的复合材料的显微硬度、抗拉强 度和导电率分别为140HV、420MPa和76%IACS，具有良好的综合性能 关关 键键 词：词：Cu-0.8Cr合金，Cu-Cr2O3(RE)复合材料，内氧化，动力学模型 论文类型：论文类型：应用基础研究 摘要 III Subject: Study of internal oxidation kinetics and properties of RE micro alloying Cu-Cr alloy Specialty: Materialogy Engineering Name: Zhang Jin-dong Supervisor: Associate Professor Liu Yong ABSTRACT The composite material of dispersion-strengthen copper owned high thermal conductivity, high electrical conductivity and excellent high temperature strength, high-temperature creep resistance, good wear-resistance and so on, is widely used in electromechanical, electronics, aerospace and nuclear fields. The internal oxidation process has become a focus of the composite materials of dispersion-strengthen copper. In this paper, the embedded internal-oxidation process was used to prepare the composite material of Cu-Cr2O3(RE), and Cu-0.8Cr alloys contained different content of Ce were used as raw materials. The feasibility of the surface internal-oxidation of Cu-0.8Cr alloys was discussed from the thermodynamic view. For controlling the internal-oxidation process, the internal-oxidation kinetic models of the platy and the cylindrical specimens were established based on the unsteady-state diffusion of oxygen within the matrix of Cu-0.8Cr alloy. The effects of rare earth Ce on microstructure and properties of Cu-0.8Cr alloy was investigated, and the effects of rare earth Ce during the process of cold deformation on microstructure and properties of Cu-0.8Cr alloy was also investigated. The results show that: 1. Cu-Cr alloy oxidation occurs within the upper limit of oxygen partial pressure: 2 Cu O ( 41065/29.94)PexpT=−+ Lower partial pressure of oxygen is as follows: 2 Cr O ( 59912/17.73)PexpT=−+ 河南科技大学硕士学位论文 IV 2. The internal-oxidation kinetic equation of the platy specimens of Cu-Cr alloy is as follows: 2 OO OCr 4 0.6293 N D Xt NN =⋅ + And the internal-oxidation kinetic equation of the cylindrical specimens of Cu- Cr alloy is as follows: 222 OO 12212 Cr 41 ()ln( /) 23 N D rrrr rt N −−=⋅ The test results are in good agreement with the two models 3. The thickness of oxide layer increases continuously with the increase of internal oxidation time and temperature. A small amount of Ce addition accelerates the internal oxidation process of Cu-0.8Cr alloy. Under this experimental condition, the oxide layer depth of the cylinder specimen of Cu-0.8Cr-0.2Ce alloy is up to 798μm at 950℃ for 12h. 4. Rare Earth Ce addition can refine the grain size and improve the hardness, conductivity and tensile strength. The micro-hardness, conductivity, tensile strength of Cu-Cr alloy before oxidation are respectively 92HV, 54.7%IACS, 247MPa compared to the Cu-Cr alloy adding 0.2% Ce after oxidation, then the hardness, conductivity and tensile strength are 128HV, 80%IACS, and 400MPa, respectively. 5. After internal oxidation, the hardness and tensile strength significantly increases and the conductivity decreases with the deformation increase. When the strain is 80%, the micro-hardness, tensile strength and conductivity of the composite material contained 0.2wt%Ce are 140HV, 420MPa and 76% IACS, respectively. The material has a excellent comprehensive performance. KEY WORDS: Cu-0.8Cr alloy, Cu-Cr2O3(RE) composites, internal oxidation, kinetics model Dissertation Type: Application fundamental research 第 1 章 前言 1 第第 1 章章 前言前言 铜具有高的导电性、导热性及优良的加工工艺性能，广泛应用于机电、电 子、宇航和原子能等领域[1]，但是纯铜的室温强度和高温强度均较低，难以满足 实际应用的需要。
因此，如何在保持较高电导率水平的前提下，显著提高强度已 成为铜基材料研究与开发的中心任务现有的铜合金难以兼顾高导电率和高强 度，强度的提高往往是以较大程度的牺牲导电率为代价的而复合强化既能同时 发挥基体及强化材料的协同作用，又具有很大的设计自由度 弥散强化铜复合材料是一类以高强度、高稳定、高硬度、高温抗蠕变性能、 耐磨损的陶瓷颗粒作为增强体的高性能铜基复合材料，它属于颗粒增强金属基复 合材料，以其优良的力学性能和导电、导热性能以及良好的抗高温软化能力，成 为近年来研究焦点其中，内氧化工艺是目前制备弥散强化铜复合材料研究最为 活跃和进展最大的领域之一 1.1 弥散强化铜基复合。