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摘要通过形变热处理的晶界工程方法可实现特征分布优化，提高材料耐蚀性。本文以工业纯铜(99.97%)为材料，通过等径角挤压(ECAP)及冷轧对纯铜引入内应力，探究不同变形方式对晶界结构影响的机理，得出以下结论：
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(1)纯铜通过ECAP1道次变形及退火温度350℃，退火时间48h条件下，特殊晶界比率由母材的63.94%提高到处理后的71.06%，电化学测试DOS值由母材的0.23降到0.04，抗腐蚀性改善。
(2)纯铜在58%变形量冷轧变形及退火温度350℃，退火时间24h条件下，特殊晶界比率提高到处理后的69.42%，电化学测试DOS值降到0.04，抗腐蚀性改善。33952
(3)ECAP和冷轧都可实现晶界结构优化。在相同等效应变条件下，ECAP引入的内应力高于冷轧变形引入的内应力。对比两种方式的晶界结构优化的最优工艺，ECAP所需退火时间更长。
关键词 纯铜 等径角挤压 冷轧 晶界工程 晶界特征分布
毕业论文设计说明书外文摘要
Title Effect of the deformation mode on the grain boundary character distribution and corrosion resistance of the pure copper
Abstract
Through the thermo-mechanical process, the approach of the grain boundary engineering are able to optimize the grain boundary character distribution and improve the corrosion resistance.
This paper studies the commercially pure copper (99.97%) using the equal channel angular pressing (ECAP) and the cold rolling technique. It aims to explore the mechanism of the impact on the grain boundary structure through different deformation modes. The results provide theoretical analysis and experimental evidences and contribute to the improvement of grain boundary structure optimization. The main results are illustrated as follow:
(1) After 1 pass of ECAP transformed and the further thermo-mechanical processing, the pure copper’s special grain boundary ratio turns to 71.06% from the original material 63.94%, under the annealing condition of 330 and 48 hours. Besides, the DOS decrease from 0.23 to 0.04, and the anti-corrosion resistance improves significantly.
(2) After 58% cold rolled and the further thermo-mechanical processing, the pure copper’s special grain boundary ratio turns to 69.42%, under the annealing condition of 330 and 24 hours. Besides, the DOS decrease to 0.04, and the anti-corrosion resistance improves significantly.
(3)Both ECAP and cold rolling techniques can achieve the refinement of the grain boundary. Comparing the optimal technique between them, the time ECAP takes is longer. Under the equivalent strain conditioning, the internal stress that ECAP induces is larger than the cold rolling.
Keywords pure copper Equal Channel Angular Pressing cold rolling grain boundary engineering grain boundary character distribution
目 次
第一章 绪论 1
1.1 引言 1
1.2 晶界工程 1
1.2.1 晶界工程简介 1
1.2.2 晶界工程改善材料性能的机理 1
1.2.3 实现晶界工程的途径 2
1.2.4 GBCD优化的判据 2
1.2.5 晶界特征分布的测定 2
1.2.6 晶界工程的研究进展 3
1.3 变形方式 3
1.3.1 冷轧 3
1.3.2 ECAP技术 4
1.3.3 ECAP和冷轧的区别 5
1.4 论文研究的主要内容 5
第二章 实验过程和方法 6
2.1 实验材料 6
2.2 实验仪器 6
2.3 实验流程 6
2.4 实验方法 7
2.4.1 固溶处理 7