摘要为了改善材料的整体力学性能，进而在工业应用方面上发挥出更大的作用，学者们提出了梯度纳米结构这一概念。对于具备梯度纳米结构的材料，其表面晶粒被细化至纳米尺度，加之梯度结构的协作效应，使得纳米结构梯度材料各项性能有明显的提高，受到广泛关注。81225

本课题使用旋转加速喷丸法（RASP）对316L不锈钢进行表面纳米化处理，制得了多组梯度纳米结构316L不锈钢样品。随后，我们对所得的样品进行了金相组织观察、硬度测试以及拉伸测试，并对其组织结构和各项性能作了详细的分析。通过实验，我们发现梯度纳米结构316L不锈钢样品表面发生强烈的塑性变形，表面晶粒细化，硬度和强度明显增大，但塑性下降。

毕业论文关键词  梯度纳米结构 316L不锈钢 旋转加速喷丸 组织结构 性能

毕业设计说明书外文摘要

Title    A research on 316L stainless steel with gradient  nanostructures                                                     

Abstract To improve the overall mechanical properties of the material and promote its application, gradient nanostructures have been put forward recently。 For materials with a gradient of nanostructures, the surface grains are refined to the nanometer scale, together with the interplay between the gradients,the properties of the gradient nanostructured materials shows a big improvement when campared to conventional materials。

In this paper, 316L stainless steel was processed by Rotational Accelerated Shot Peening (RASP) treatment and its gradient nanostructure were introduced。 A sets of samples were conducted to investigate the microstructures and mechanical properties of the gradient nanostructured 316L stainless steel。It is found that after the surface treatment, strong plastic deformation occurs in the surfacelayer of the 316L stainless steel and microstructures/hardness gradient were observed。  Hardness and strength of the gradient nanostructued 316L stainless steel were significantly increased while the ductility decreases drastically。

Keywords  Gradient nanostructure; 316L stainless steel; Rotational Accelerated Shot Peening; Microstructure; Mechanical properties

目   次

1  绪论 1

1。1  纳米材料与纳米技术 1

1。2  梯度纳米结构材料 1

1。3  表面纳米化 2

1。4  梯度纳米结构材料的性能特点 4

1。4。1  表面硬度与耐磨性 4

1。4。2  疲劳性能 5

1。4。3  拉伸性能 5

1。5  梯度纳米结构316L不锈钢的研究现状 6

1。6  本课题研究的主要内容 6

2  实验部分 7

2。1  实验材料 7

2。2  样品制备过程 8

2。3  样品的性能测试与表征 9

2。3。1  金相组织分析 9

2。3。2  样品硬度测试 10

2。3。3  样品拉伸测试 11

3  实验结果与数据分析