1420铝锂合金细晶板材高温力学性能及本构方程  

High temperature mechanical properties and constitutive equation of 1420 Al-Li alloy fine-grained sheet metal

作　　者：肖瑞[1] 赛音 李保永[1] 刘伟 刘奇[1] XIAO Rui;SAI Yin;LI Bao-yong;LIU Wei;LIU Qi(Beijing Hangxing Machinery Manufacturing Co.,Ltd.,Beijing 100191,China;Second Military Representative Office of Air Force Equipment Department,Beijing 100191,China)

机构地区：[1]北京航星机器制造有限公司,北京100191 [2]空军装备部驻北京地区第二军事代表室,北京100191

出　　处：《塑性工程学报》2021年第6期61-67,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金青年科学基金资助项目(51905512)。

摘　　要：为了获取1420超塑铝锂合金细晶板材的高温流动变形行为和可靠的本构方程,在应变速率为0.0004~0.002 s^(-1),温度为375~425℃条件下对板材进行了高温拉伸试验,采用EBSD观察了不同变形温度下的晶粒尺寸和晶界分布,分析了组织演变规律。结果表明,板材在低温环境下变形时具有初始硬化和随后的流动软化特征,在较高温度下加工硬化起主导作用;基于Arrhenius型本构方程拟合多项式并进行求解,获得板材变形激活能为97879 J·mol^(-1);同时,板材的平均晶粒尺寸仅为1.25μm,在425℃和0.0012 s^(-1)下的伸长率达到最高,为670%;由于温度和晶粒变化的平衡作用,材料的塑性在不同条件下并未产生较大变化。To obtain the high temperature flow deformation behavior and reliable constitutive equation of 1420 superplastic Al-Li alloy fine-grained sheet metal,the high temperature tensile test was carried out at the strain rate of 0.0004-0.002 s-1 and the temperature of 375-425℃.The distribution of grain size and grain boundary at different deformation temperatures was observed by EBSD,and the microstructure evolution law was analyzed.The results show that the sheet metal shows the charcteritics of initial hardening and subsequent flow softening at low temperature,and the work hardening plays a dominant role at high temperature;polynomial is fitted and solved based on the Arrhenius type constitutive equation,and the deformation activation energy of sheet metal is 97879 J·mol^(-1);at the same time,the average grain size of the sheet metal is only 1.25μm,and the maximum elongation reaches 670%at 425℃ and 0.0012 s^(-1).Due to the balance action of temperature and grain changes,the plasticity of the material under different conditions is not changed greatly.

关 键 词：铝锂合金 高温拉伸 本构方程 组织演变规律 

分 类 号：TG304[金属学及工艺—金属压力加工]