Mg含量对w(Zn)=11%的超高强铝合金组织性能的影响
Influence of Mg content on the microstructure and mechanical properties of w(Zn)=11%ultra-high strength aluminum alloy
鲁法云 1范云强 1肖翔 1陈星翰 2吴浩 1王国军 1吕丹 3刘成1
作者信息
- 1. 中铝材料应用研究院有限公司,北京 102209
- 2. 北京科技大学,北京 100083
- 3. 东北轻合金有限责任公司,黑龙江 哈尔滨 150060
- 折叠
摘要
研究了Mg含量对w(Zn)=11%超高强铝合金组织性能的影响.超高强铝合金铸锭为网状枝晶组织,平均晶粒尺寸约170～240 μm,铸锭组织中存在粗大的α(Al)+T(AlZnMgCu)共晶相.经均匀化退火后,w(Mg)<1.75%的合金组织中粗大的T相完全回溶,w(Mg)>2.0%的铸锭组织中还有少量T相残留.超高强铝合金挤压材固溶处理后,组织中T相完全回溶,组织为纤维组织,再结晶比例约1.2%～6.5%,纤维条带宽度约24.2～35.4 μm.挤压材时效后,组织中分布高密度的析出强化相,主要为GP区和η'相,尺寸为2～5 nm.随Mg含量增加,合金的屈服强度由687 MPa升高到782 MPa,抗拉强度由717 MPa升高到795 MPa,伸长率从12.5%降低到9.3%.w(Zn)=11%的超高强铝合金中析出强化相的数量与Mg含量成正比,Mg含量增加,合金强度升高.
Abstract
The influence of Mg content on the microstructure and mechanical properties of w(Zn)=11%ultra-high strength aluminum alloy has been systematacially investigated.The ingot microstructure is dendritic structure,the average grain size is 170-240 μm,and coarse α(Al)+T(AlZnMgCu)eutectic phase exists.After homogenization annealing,coarse T phase dissolves into matrix completely in w(Mg)<1.75%alloys,while a slight a-mount of T phase is retained in w(Mg)>2.0%alloys.After hot extrusion and solution treatment,the T phase is dissolved completely,the microstructure is fiber band,the average fiber band width is 24.2-35.4 μm,and the recrystallization fraction is 1.2%-6.5%.Af-ter peak aging treatment,high-density strengthening precipitates in matrix are mainly GP zone and η′phase with size of 2-5 nm.As the Mg content rises,the yield strength increa-ses from 687 MPa to 782 MPa,and the tensile strength increases from 717 MPa to 795 MPa,while the elongation decreases from 12.5%to 9.3%.In w(Zn)=11%ultra-high strength aluminum alloys,the strengthening precipitates amount is proportional to Mg content,so the alloy strength increases with Mg content rising.
关键词
超高强铝合金/Mg含量/拉伸性能/η'析出相Key words
ultra-high strength aluminum alloy/Mg content/tensile properties/η′ pre-cipitates引用本文复制引用
基金项目
国家重点研发计划项目(2023YFB3710501)
出版年
2024
NETL
NSTL
万方数据