( 1. 重庆大学 材料科学与工程学院, 重庆 400044;
2. 西南铝业(集团)有限责任公司, 重庆 401326)
摘 要: 在Gleeble-1500D热模拟仪上进行热压缩实验, 研究了变形温度为573~773 K、 应变速率为0.01~10 s-1时2618铝合金的热变形行为。 热变形过程中的稳态流变应力可用双曲正弦本构关系式来描述, 平均激活能为181 kJ/mol, 大于其自扩散激活能。 根据材料动态模型, 计算并分析了2618铝合金的加工图。 利用加工图确定了热变形的流变失稳区, 并且获得了试验参数范围内的热变形过程的最佳工艺参数, 其热加工温度为623~723 K, 应变速率为0.01 s-1, 温加工温度为573 K左右, 应变速率为0.01 s-1。
关键字: 2618铝合金; 流变应力; 加工图; 热变形
2618 aluminum alloy
( 1. College of Materials Science and Engineering,
Chongqing University, Chongqing 400044, China;
2. Southwest Aluminium Group Co., Ltd.,
Chongqing 401326, China)
Abstract: The deformation behaviour of 2618 aluminum alloy was investigated by compression tests with Gleeble-1500D thermal simulator system. The tests were performed in the temperature range between 573 and 773 K and strain rates between 0.01 and 10 s-1. The flow behaviour is described by the hyperbolic sine constitutive equation, and an activation energy of 181 kJ/mol greater than the activation energy for self-diffusion in Al is calculated. The processing maps were calculated and analyzed according to the dynamic materials model. The process of hot deformation in the temperature range and different strain rate can be attained by the maps, which hot deformation temperature is 623-723 K and strain rate is around 0.01 s-1. The warm deformation temperature is approximately 573 K and strain rate is also about 0.01 s-1. The instability zones of flow behaviour can also be recognized by the maps.
Key words: 2618 aluminum alloy; flow stress; processing maps; hot deformation