6005A与6082铝合金热变形流变行为  

Flow behaviors of 6005A and 6082 aluminum alloys during hot deformation

作　　者：丁贤飞[1] 张利欣[1] 孙冬柏[1] 王志海[2] 王立臣[3] 李恒奎[4] 

机构地区：[1]北京科技大学国家材料服役安全科学中心,北京100083 [2]唐山轨道客车有限责任公司,唐山063035 [3]吉林麦达斯铝业有限公司,辽源136200 [4]南车青岛四方机车车辆股份有限公司,青岛266611

出　　处：《北京科技大学学报》2012年第9期1041-1047,共7页Journal of University of Science and Technology Beijing

基　　金："十一五"国家科技支撑计划资助项目(2009BAG12A07--B01--2)

摘　　要：利用Gleeble--1500热模拟试验机对6005A和6082铝合金进行高温等温压缩试验,研究了在变形温度为450～550℃和应变速率为0.005～10 s-1条件下两种铝合金的热变形流变行为.6005A铝合金在低应变速率条件下,不同变形温度时的流变曲线均呈现波浪形特征,随着应变速率的增加,硬化和软化接近平衡,表现为稳态流变特征;在高应变速率条件下,硬化过程占据主导地位,回复和硬化过程的竞争使流变曲线呈现波浪形上升的趋势.6082铝合金在低应变速率情况下,不同变形温度时的流变曲线未出现周期性波动;在中等应变速率条件下也表现为稳态流变特征;在高应变速率条件下出现波浪形特征.两种铝合金均为正应变速率敏感材料,其热变形是受热激活控制.最后给出了铝合金热变形条件下流变应力、应变速率和变形温度三者之间的关系式.The flow behaviors of 6005A and 6082 aluminum alloys were investigated by high-temperature isothermal compression on a Glebble-1500 thermal-mechanical simulator at deformation temperatures of 450 to 550 ℃ and strain rates of 0. 005 to 10 s^-1. The flow stress curve of 6005A aluminum alloy exhibits a waveform character at different deformation temperatures under the condition of low strain rate. With increasing strain rate the competition between softening and hardening closely reaches to a balance so that the flow stress appears as a steady state. At high strain rate, the hardening is dominant during the hot deformation and there is a waveform in- crease in the flow stress curve because of the competition between reverting and hardening. The flow stress curve of 6082 aluminum al- loy, however, does not show the waveform character at low strain rate. A steady-state stress is also displayed at medium strain rate. But the waveform flow curve is shown at high strain rate. Both of the alloys are positive strain rate sensitive materials and their hot de- formation is controlled by the thermal activation. Finally the relationships among flow stress, strain rate and deformation temperature were proposed for 6005A and 6082 aluminum alloys, respectively.

关 键 词：铝合金 压缩试验 高温试验 流变应力 应变速率 

分 类 号：TG146.2[一般工业技术—材料科学与工程]