摘要纳米材料由于具有独特的微观结构和优异的性能而备受关注。本文利用喷丸方法在纯铜表面获得了一定厚度的纳米结构表层，采用金相显微镜(OM)和显微硬度测试仪对喷丸后样品的微观组织结构和性能进行了表征。主要研究结果如下：喷丸引起的强烈塑性变形在样品表面随机发生，并且在横截面随着深度的增加强烈塑性变形量逐渐地减小，变形层大约有200 ，从而使得样品的晶粒尺寸也呈现随距离样品表面深度的增大而逐渐减小的梯度变化趋势；喷丸后样品表面层的显微硬度明显增大，表层硬度比变形层以外区域的硬度提高大约60HV，并且随着深度的增大显微硬度值逐渐减小。极化腐蚀实验结果表明，腐蚀性能随距表面深度而变化, 在130 至160 和300 深度附近的腐蚀电位高于未喷丸试样。67784

毕业论文关键词   纯铜  表面机械化  喷丸  显微结构  性能

毕业设计说明书（论文）外文摘要

Title   Characterization and properties of pure metal  induced by surface mechanization                

Abstract

Nanostmctured metallic materials have been the subject of considerable research due to their unique microstructures and appealing mechanical properties．In this paper,the nanostmctured surface layer was obtained on pure copper plates by using shot peening. Microstucture features of various sections in the surface layer and properties of the shot peening samples were systematically characterized by using optical microscope(OM)，and microhardness testing machine．The main conclusions can be drawn as follows：During shot peening,severe plastic deformation occurs randomly on the surface layer,and decreases gradually along the depth(200 ) of the treated samples,which results in the gradient variation of the microstructures. With the depth increasing，the size of grains increases depending on the gradient variation of microstructures. After the shot peening，the micro—hardness of the surface layer in the Copper samples is evidently enhanced. The hardness decreases by 60HV gradually with the increase in depth． The polarization curves show that the corrosion potentials of shot peening copper plates from 130  to 160  and 300  in depth are better than untreated.

Keywords Pure copper  Surface mechanization  Shot peening  Microstructure  Property

目   次  

1  绪论 1

1.1  实现表面纳米化的三条途径 2

1.2  表面纳米化的基本原理 3

1.3 实用表面纳米化技术 3

1.4  表面纳米层的性能 6

1.5 金属材料表面纳米化的应用前景 9

2  实验方法 9

2.1  样品制备 10

2.2 样品结构和性能的表征方法 11

3  实验结果与分析 12

3.1  金相组织(OM)观察与分析 12

3.2  表面纳米化后试样显微硬度的变化 15

3.3  表面纳米化对试样的腐蚀行为的影响 16

结论 21

致谢 22

参 考 文 献