作　　者： ; ; ; ;

机构地区： 中南大学材料科学与工程学院

出　　处： 《中南大学学报（自然科学版）》 2013年第3期914-920,共7页

摘　　要： 采用Gleeble-1500热/力模拟试验机进行压缩实验,研究Al-6Mg-0.4Mn-0.2Sc铝合金在变形温度为300～500℃、应变速率为0.001～10s-1范围内的变形行为。计算应力指数和变形激活能,并采用Zener-Hollomon参数法构建合金高温塑性变形的本构关系。根据材料动态模型,计算并分析合金的加工图。研究结果表明: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158.92kJ/mol,大于其自扩散激活能。根据加工图确定了热变形的流变失稳区,并且获得了热变形过程的最佳工艺参数,其热加工温度为430～480℃,应变速率为5～10s-1,温加工温度为320～400℃、应变速率为0.01～0.001s-1。 The hot deformation behavior of Al-6Mg-0.4Mn-0.2Sc aluminum alloy was investigated by hot compressive tests on Gleeble-1500 thermal simulation test machine at 300-500℃and strain rates of 0.001-10 s-1.The stress exponent and the deformation activation energy at elevated temperatures were calculated.The constitutive equation of the plastic deformation of Al-6Mg-0.4Mn-0.2Sc alloy at elevated temperatures was obtained by introducing Zener-Hollomon parameter.The processing maps were calculated and analyzed according to the dynamic materials mode.The results show that the flow behaviour is described by the hyperbolic sine constitutive equation,and an activation energy of 158.92 kJ/mol is greater than the activation energy for self-diffusion in Al.The process of hot deformation in the temperature range and different strain rate can be attained by the maps.The hot deformation temperature is 430-480℃,strain rate is around 5-10 s-1,warm deformation temperature is 320-400℃and strain rate is 0.01-0.001 s -1.The instability zones of flow behaviour can also be recognized by the maps.

关 键 词： 流变应力 加工图 热变形 铝合金

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]