摘要：本研究课题利用自主研发的旋转加速喷丸技术在纯钛表面获得梯度纳米结构，该方法的原理是利用循环往复的载荷使金属材料表面发生剧烈的塑性变形，达到最表面晶粒尺寸小于100纳米，且晶粒尺寸从表面到心部呈梯度变化的结构。这种方法制备的材料具有非常好的综合力学性能，但塑性相对粗晶材料大幅下降，影响其在工业中的应用。
本课题拟对梯度结构纯钛样品进行退火处理和轧制处理，以研究其微观组织和力学性能的变化趋势，主要结论如下：
（1）RASP处理后进行退火处理，随着退火温度的增加试样表面变形层的厚度减小，晶粒度增大，晶粒尺寸趋向均匀，使得试样沿着厚度方向力学性能更均匀。RASP+退火处理后的试样表面硬度最高，随着距表面距离的减小硬度值逐渐下降，但试样心部显微硬度仍高于退火态试样（CG）。
（2）RASP处理后进行轧制，随着轧下量的增加试样表面变形层的厚度增加；且RASP处理试样变形区域较小，集中在表面区域，经轧制处理后试样心部也有一定程度的变形，使得试样沿着厚度方向力学性能更均匀。
（3）退火态试样经轧制后在内部引入应力与应变，诱发孪生系的开动，在微观应变与孪晶的作用下其力学性能得到提升。
关键词 RASP纳米梯度结构退火轧制力学性能
毕业设计说明书外文摘要
Abstract：In this study, the gradient nanostructures were obtained on the pure titanium surface by the self-developed rotary accelerating shot peening technique. The principle of this method was to use the cyclic reciprocating load to make the plastic deformation on the surface of the metal material to reach the surface grain size less than 100 nanometers , And the grain size from the surface to the heart of the gradient structure. The method of preparation of the material has a very good comprehensive mechanical properties, but the plastic relative to the coarse material decreased significantly, affecting its application in industry.
In this paper, the samples of pure titanium samples are annealed and rolled to study the microstructure and mechanical properties of the samples. The main conclusions are as follows:
(1) After annealing with RASP, the thickness of the surface deformation layer decreases with the increase of the annealing temperature, the grain size increases and the grain size tends to be uniform, which makes the specimen more uniform in the thickness direction. The surface hardness of RASP + annealed is the highest, and the hardness of the specimen is still higher than that of the annealed specimen (CG), as the hardness decreases from the surface distance.
(2) After RASP treatment, the thickness of the surface deformation layer increased with the increase of the rolling amount. The deformation area of the RASP treated sample was smaller and concentrated in the surface area. After the rolling treatment, There is a certain degree of deformation, making the specimen along the thickness of the mechanical properties more uniform.
(3) The annealed specimen is introduced into the stress and strain after rolling,and the start of the twin system is induced, and the mechanical properties are improved under the action of microstrain and twin.
Keywords RASP Nano - gradient structure Annealing Rolling Mechanical properties
目 次
1 绪论 1
1.1 引言 1
1.2 RASP纯钛表面获得梯度纳米结构:http://www.chuibin.com/cailiao/lunwen_205155.html