(北京科技大學(xué) 新材料技術(shù)研究院 材料先進(jìn)制備技術(shù)教育部重點(diǎn)實(shí)驗(yàn)室，北京 100083)
摘 要: 以Al-Zn-Mg-Cu合金為對(duì)象，研究了擠壓溫度對(duì)合金組織、織構(gòu)及力學(xué)性能的影響。結(jié)果表明：當(dāng)擠壓溫度為390~500 ℃時(shí)，隨著擠壓溫度的升高，擠壓態(tài)棒材發(fā)生動(dòng)態(tài)再結(jié)晶程度由2.4%逐漸增大到41.3%，動(dòng)態(tài)再結(jié)晶晶粒尺寸逐漸增大，而經(jīng)固溶時(shí)效后，晶粒尺寸呈先增大后減小的變化趨勢(shì)，其中擠壓溫度為430 ℃時(shí)的晶粒尺寸最大。擠壓棒材固溶時(shí)效后的強(qiáng)度和伸長(zhǎng)率均呈先增大后減小的趨勢(shì)，其中擠壓溫度為430 ℃時(shí)的抗拉強(qiáng)度、屈服強(qiáng)度和伸長(zhǎng)率均較高，分別為678.1 MPa、618.3 MPa和9.2%。與晶粒尺寸較小的時(shí)效態(tài)擠壓棒材相比，晶粒尺寸較大的棒材具有更高的強(qiáng)度，其原因是由于大晶粒棒材中存在較多的硬取向Copper織構(gòu)({112}á111？)和S型織構(gòu)({123}á634？)。
關(guān)鍵字: Al-Zn-Mg-Cu合金；擠壓溫度；晶粒尺寸；力學(xué)性能；織構(gòu)
（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
