摘要表面纳米化是近二十年迅速发展起来的一种极具潜能的纳米技术。本文以T2纯铜为实验原料，利用新研制的旋转加速喷丸设备（RASP）进行处理，以实现纯铜的表面纳米化，实验参数：弹丸直径 3mm，速率 25m/s，处理时间 15min、30min。 RASP 处理得到的两个表面纳米化纯铜样品，除了对其金相和硬度进行了观察和测试，还使用了扫描电镜（SEM） 、透射电镜（TEM）对其相关性能进行了测试与表征。最终，得到如下的结论： 21586
1．纳米化纯铜的表面层晶粒尺寸沿厚度方向逐渐增大，呈梯度分布，由纳米量级增至微米量级，最表面晶粒尺寸最小；
2．纳米化纯铜的表面层硬度沿厚度方向逐渐减小，最表面的硬度值最大；
3．纳米化表面层的铜含量高达98%以上，受处理过程的杂质元素污染较少；
4．喷丸处理 30min 的纯铜样品表面层的平均晶粒尺寸为 20nm-30nm，晶粒取向随机分布。
毕业论文关键词 表面纳米化 旋转加速喷丸 纳米晶材料 纯铜 塑性变形
Title Micro-structures observation in copper induced by
surface nanocrystallization treatment
Abstract
Surface nanocrystallization is a promising nanotechnology that developed
rapidly in nearly two decades. In the paper, T2 pure copper was treated
by a new Rotational-Assisted-Shot-Peening (RASP) equipment in order to
achieve surface nanocrystallization. Experimental parameters include :the
impact ball diameter is 3mm, speed is 25m/s, processing time is 15min and
30min, respectively.
The surface nanocrystallization pure copper samples were tested and
characterized by scanning electron microscope(SEM) and transmission
electron microscope(TEM), the optical micro-structure and hardness tests
were also performed. Following is the results:
1.Metallographic structure on surface nanocrystallization layer of copper
treated by RASP has a gradient distribution along the thickness direction.
With increasing depth from the RASP treated surface, grain sizes increase
and vary from nano-level to micron-level;
2. The hardness on surface nanocrystallization layer of copper gradually
decreases along the thickness direction, the extreme surface layer is
maximum, respectively reached to 143HV and 125HV;
3. The copper content of the extreme surface nanocrystallization layer in
copper treated by RASP is over 98%, which shows that the copper samples
is nearly not polluted by impurity elements in the machining process;
4.The average grain size of surface nanocrystallization layer is 20nm-30nm
in copper treated by RASP, the treatment time is 30min. Meanwhile，the
crystal orientation of the surface nanocrystallization layer is random
distributed.
Keywords Surface nanocrystallization; RASP; Nanocrystalline materials; Copper; Plastic deformation。
目 次
1 绪论 . 1
1．1 表面纳米化的制备方法 1
1．2 表面自身纳米化的结构特征和性能 3
1．3 塑性变形导致纳米化机理 4
1．4 纯铜的表面纳米化研究状况 5
1．5 表面纳米化材料的应用 8
1．6 本文研究的内容 8
2 实验部分 . 9
2.1 实验材料与设备 . 9
2.2 试样的制备与测试 10 纯铜表面纳米化处理结构观察:http://www.youerw.com/cailiao/lunwen_13854.html