论文部分内容阅读
通过对粉末冶金法制备的7075铝合金在150~400℃进行1~4道次等通道挤压(ECAP),采用光学显微镜(OM)、扫描电镜(SEM)和透射电镜(TEM)分析了挤压工艺对7075铝合金显微组织和力学性能的影响。研究表明:挤压后7075铝合金试样表面的光滑度随着挤压温度的升高显著提高。随着ECAP温度的升高,7075铝合金的抗拉强度先升高后降低,伸长率变化趋势相反,ECAP温度为250℃时,7075铝合金综合性能最佳。随着ECAP道次的增加,合金致密度、硬度及室温抗拉强度明显提高,伸长率先降低后提高;在2道次ECAP后,由于细晶强化与位错强化的双重作用,合金抗拉强度达到375 MPa。
The 7075 aluminum alloy prepared by the powder metallurgy method was subjected to 1 to 4 passes of ECAP at 150 to 400 ° C. Optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) Effect of Pressing Technology on Microstructure and Mechanical Properties of 7075 Aluminum Alloy. The results show that the smoothness of the surface of 7075 aluminum alloy after extrusion is obviously increased with the increase of extrusion temperature. With the increase of ECAP temperature, the tensile strength of 7075 aluminum alloy first increases and then decreases, while the elongation changes with the opposite trend. When the ECAP temperature is 250 ℃, the overall performance of 7075 aluminum alloy is the best. With the increase of ECAP pass, the density, hardness and room temperature tensile strength of the alloy increased obviously, while the elongation decreased first and then increased. After two passes of ECAP, the tensile strength of the alloy was increased due to the dual effect of fine grain strengthening and dislocation strengthening The strength reaches 375 MPa.