纯铝和纯铜在管状材料高压切变过程中复合行为研究

发布时间：2018-01-04 16:05

本文关键词：纯铝和纯铜在管状材料高压切变过程中复合行为研究　出处：《南京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：通过管状材料高压切变技术分别对纯铝(99.98%和99.999%)与纯铜(99.98%)进行了不同应变量的复合试验,通过光学显微镜、电子扫描显微镜、电子背散射衍射技术及能谱分析技术对复合界面及其周围的显微组织进行了表征,并通过剪切试验对其复合界面的剪切结合强度进行了检测。发现在不同的变形条件下对复合界面结合强度产生不同的影响。随着平均等效应变量的提高,复合界面结合效果得到明显改善,并在较高应变量下达到饱和,实现了界面有效的冶金结合。而在较高静水压力及较低应变速率范围内,静水压力和应变速率对复合界面的结合效果影响不太明显。实验前对样品表面进行预处理能够显著促进复合界面的冶金结合。但是由于管壁内沿半径方向应变梯度的存在,在相同转动角度条件下,内层金属的等效应变量会大于外层金属的等效应变量,从而造成内层金属的加工硬化程度相对更大,而不利于变形的继续进行,因此在不同材料的复合试验中,内层金属适宜选择加工硬化能力或强度较低的材料。我们还发现高纯铝(99.999%)和低纯铝(99.98%)在管状材料高压切变过程中表现出不同的显微组织演化及织构演化特征,而在铜铝复合界面则观察到了明显的原子相互扩散现象。通过对管状材料高压切变技术的变形特点及试样表面的分析,我们发现试样在加压过程中减薄及在变形过程中产生弯折是管状材料高压切变过程中,材料内外层复合出现新增界面的两个主要来源,而后者占据了主导作用。
[Abstract]:The high pressure tubular material shear technique in pure aluminum (99.98% and 99.999%) and copper (99.98%) of composite testing different variables, by means of optical microscope, scanning electron microscope, energy spectrum analysis and microstructure of composite interface and its surrounding technology were characterized by electron backscatter diffraction, and through shear test the composite interface bonding strength were tested. Found in different deformation conditions of composite interface strength have different effects. With the average effect variables increase, composite bonding effect is improved, and at the higher strain reaches saturation, the metallurgical interface at high effective combination. Hydrostatic pressure and low strain rate range, hydrostatic pressure and strain rate effect on the combined effect of composite interface was not obvious. On the surface of the sample before the experiment. The pretreatment can significantly promote the composite metallurgical bonding interface. But due to the presence of strain along the radius direction of the gradient in the tube wall, in the same rotation angle under the condition of the inner metal effect variables will be greater than the outer metal effect variables, resulting in hardening degree of inner metal is relatively large, and is not conducive to deformation therefore, the composite test of different materials, the inner layer metal suitable work hardening ability or low strength materials. We also found that high purity aluminum (99.999%) and low (99.98%) in pure aluminum tubular material high shear process showed the microstructure and texture evolution of different evolution characteristics, and in the composite interface copper is observed obvious atom diffusion phenomenon. Through the analysis of the deformation characteristics and the surface of the tubular material pressure shear technology, we found that the sample in the pressure process Thinning and bending in the course of deformation are two main sources of new interfaces added to the inner and outer layers of pipes during the high-pressure shear process, while the latter occupy the leading role.

【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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