(北京科技大学 新材料技术研究院 材料先进制备技术教育部重点实验室，北京 100083)
摘 要: 以Al-Zn-Mg-Cu合金为对象，研究了挤压温度对合金组织、织构及力学性能的影响。结果表明：当挤压温度为390~500 ℃时，随着挤压温度的升高，挤压态棒材发生动态再结晶程度由2.4%逐渐增大到41.3%，动态再结晶晶粒尺寸逐渐增大，而经固溶时效后，晶粒尺寸呈先增大后减小的变化趋势，其中挤压温度为430 ℃时的晶粒尺寸最大。挤压棒材固溶时效后的强度和伸长率均呈先增大后减小的趋势，其中挤压温度为430 ℃时的抗拉强度、屈服强度和伸长率均较高，分别为678.1 MPa、618.3 MPa和9.2%。与晶粒尺寸较小的时效态挤压棒材相比，晶粒尺寸较大的棒材具有更高的强度，其原因是由于大晶粒棒材中存在较多的硬取向Copper织构({112}á111？)和S型织构({123}á634？)。
关键字: Al-Zn-Mg-Cu合金；挤压温度；晶粒尺寸；力学性能；织构
（Key Laboratory for Advanced Materials Processing, Ministry of Education, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The effects of extrusion temperature on the microstructure, texture and mechanical properties of Al-Zn-Mg-Cu alloy were investigated. The results show that, when extrusion temperature increases from 390 ℃ to 500 ℃, the extent of dynamic recrystallization of the extruded bar increases from 2.4% to 41.3%, and the dynamically recrystallized grain size also increases gradually. After solid solution and aging treatments, the grain size of the extruded bars increases initially and then decreases with the increase of extrusion temperature, and the grain size reaches the maximum at 430 ℃. Meanwhile, the strength and elongation of the aged bars also increase firstly and then decrease. The tensile strength, yield strength and elongation of the aged bar extruded at 430 ℃ are relatively high of about 678.1 MPa、618.3 MPa and 9.2%, respectively. The aged bar with larger grain size has higher strength than the one with smaller grain size, which is ascribed to existence of both the stronger Copper textures ({112}á111？) and S type textures ({123}á634？) in the bars with larger grain size.
Key words: Al-Zn-Mg-Cu alloy; extrusion temperature; grain size; mechanical property; texture
