(北京有色金属研究总院，北京 100088)
摘 要: 采用Gleeble−1500D热模拟机对7075铝合金进行温度范围300~400 ℃、恒应变速率为1 /s的热压缩实验。对热变形后材料的显微组织进行透射电镜观察，研究温度对7075合金热变形过程中的显微组织演化的影响。结果表明：在本实验条件下7075合金的流变应力曲线为动态回复型流变曲线； 7075合金的显微组织演变经历由无规则排布的位错演化成胞状组织、亚晶组织、亚晶长大等过程；温度升高，显微组织的演化过程缩短，变形材料的亚晶尺寸增大。
关键字: 7075铝合金；显微组织演化；动态回复；热变形
（General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:Hot compression tests of 7075 aluminium alloy were operated on Gleeble−1500D thermal simulator at a constant strain rate of 1 /s and a temperature from 300 to 400 ℃. The microstructures of hot deformed alloy were observed by transmission electron microscopy to research the effect of temperature on microstructure evolution of 7075 Al alloy during hot deformation. The results show that the stress—strain curves under the experimental conditions belong to the type of dynamic recovery. The microstructure undergoes a process of disordered dislocations to cell structure, subgrain structure and subgrain coarsening. With increasing temperature the microstructure evolution process completes earlier and the subgrain size of the deformed material increases.
Key words: 7075 Al alloy; microstructure evolution; dynamic recovery; hot deformation
ISSN 1004-0609
CN 43-1238/TG
CODEN: ZYJXFK
ISSN 1003-6326
CN 43-1239/TG
CODEN: TNMCEW