中南大学学报（自然科学版）2017，Vol.48Issue(5)：1141-1148,8.DOI:10.11817/j.issn.1672-7207.2017.05.003
5A90铝锂合金的超塑性变形行为
Superplastic deformation behavior of 5A90 aluminum-lithium alloy
摘要
Abstract
The superplastic deformation behavior and deformation mechanism of 5A90 Al-Li alloy during superplastic deformation were studied by optical microscopy, electron back scattering diffraction, electrical conductivity test and high temperature tensile test. The results show that the elongation of the specimen which is recrystallized at 450℃ for 30 min before the tensile test can increase from 630% to 1120% at an appropriate superplastic condition, which is obtained at temperature of 500℃ and an initial strain rate of 8×10?4s?1. During the process of superplastic deformation, elongated grains gradually change to be equiaxed, and after annealing grain size becomes smaller and axis degree is higher. In addition, recrystallization annealing can improve vacancy concentration and increase the proportion of large angle grain boundary, which is beneficial to the improvement of the elongation. In the appropriate condition, the strain rate sensitivity indexm of thismaterial is 0.63, and the main deformation mechanism is GBS. But at the late stage of the deformation, diffusion is taken as a coordination mechanism.关键词
5A90铝锂合金/再结晶退火/超塑性/空位浓度/晶粒组织Key words
5A90 Al-Li alloy/recrystallization annealing/super plasticity/vacancy concentration/grain structure分类
矿业与冶金引用本文复制引用
王国玮,叶凌英,孙大翔,杨涛,陈敏,张新明..5A90铝锂合金的超塑性变形行为[J].中南大学学报（自然科学版）,2017,48(5):1141-1148,8.基金项目
国家自然科学基金资助项目(51205419) (Project(51205419) supported by the National Natural Science Foundation of China) （51205419）
