欠时效态7075铝合金热变形行为及热加工图  

Hot deformation behavior and processing maps of under-aged 7075 aluminum alloy

作　　者：聂祯一 艾云龙[1] 何文[1,2] 陈卫华[1] 王家宣 

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063 [2]江西省金属材料微结构调控重点实验室(南昌航空大学),江西南昌330063 [3]江西雄鹰铝业技术中心,江西安义330500

出　　处：《材料热处理学报》2017年第6期189-194,共6页Transactions of Materials and Heat Treatment

基　　金：江西省自然科学基金(20122BAB206015);江西省金属材料微结构调控重点实验室开放基金(JW201523005)

摘　　要：采用Gleebe-3500型热模拟试验机对7075铝合金进行等温恒应变速率热压缩实验,研究了该合金在变形温度为250~450℃、应变速率为0.001~1 s^(-1)条件下的热变形行为,并据此建立了热加工图。结果表明:流变真应力随应变速率的升高而增大,随变形温度的升高而减小;经250℃、16 h欠时效处理的样品,其峰值应力要显著大于未经时效的样品;真应变为0.3和0.7的热加工图在250~350℃的温度区间、0.01~1 s^(-1)的应变速率区间均出现流变失稳;16 h欠时效态7075铝合金的最佳热变形参数为:变形温度400~450℃、应变速率0.01~0.001 s^(-1)。The isothermal constant strain-rate compression test of 7075 aluminum alloy was carried out by using a Gleebe-3500 thermal-mechanical simulator, and the hot deformation behavior of under-aged 7075 aluminum alloy under deformation temperature of 250-450 ℃ and strain rate of 0. 001-1 s^-1 was studied, and its processing maps were established. The resuhs show that theological true stress increases with the increasing of strain rate while decreases with the increasing of deformation temperature. The peak stress of the under-aged samples after aging at 250 ℃ for 16 h is significantly higher than that of untreated ones. In the temperature range of 250-350 ℃ and the strain rate range of 0. 01-1 s^-1, unstable areas appear in the processing maps with true strains of 0. 3 and 0. 7. The optimum hot deformation processing parameters for under-aged 7075 aluminum alloy are as follows ： the deformation temperature is 400-450 ℃ and the strain rate is 0. 01-0. 001 s^-1.

关 键 词：7075铝合金 热变形 真应力 真应变 热加工图 

分 类 号：TG146.2[一般工业技术—材料科学与工程]