中南大学学报（自然科学版）2018，Vol.49Issue(6)：1340-1348,9.DOI:10.11817/j.issn.1672-7207.2018.06.005
预时效对T9I6工艺的2519A铝合金力学性能和组织演变的影响
Effects of pre-ageing on microstructure and mechanical properties of T9I6 heat-treated 2519A aluminum alloy
摘要
Abstract
The effects of pre-ageing on microstructure and mechanical properties of T9I6 heat-treated 2519A aluminum alloy were investigated by hardness tests, tensile tests, transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The results show that when the pre-ageing holding time is 80 min, both tensile strength and yield strength reach their maximum values, 491.9 MPa and 513.8 MPa respectively. However, further extending the pre-ageing holding time reduces the mechanical properties of 2519A aluminium alloy. The mechanical properties of the alloy are associated with the formation of GP zones during pre-ageing. GP zones can greatly impede the recovery caused by dislocation movement and serve as precursors forθ′ precipitates during re-ageing. When the pre-ageing holding time is 40 min, an insufficient amount of GP zones is formed to act as effective obstacles for dislocation motion. The observed decrease in strength in samples subjected to extended pre-ageing holding time is caused by the depletion of the supersaturated solid solution atoms in the matrix and, consequently, decreases the nucleation of GP zones. Also, precipitate coarsening is another reason that causes the decrease of strength.关键词
2519A铝合金/T9I6工艺/显微组织/预时效/DSC分析Key words
2519A aluminum alloy/T9I6 thermo-mechanical treatment/microstructure/pre-ageing/DSC analysis分类
矿业与冶金引用本文复制引用
董宇,叶凌英,孙大翔,王绍玲,张新明..预时效对T9I6工艺的2519A铝合金力学性能和组织演变的影响[J].中南大学学报（自然科学版）,2018,49(6):1340-1348,9.基金项目
国家重点基础研究发展规划(973计划)项目(2016YFB0300901)(Project(2016YFB0300901) supported by the National Key Research Development Program (973 Program) of China) （973计划）
