摘要
采用室温拉伸、透射电镜观察等手段,研究了3%拉伸预变形对Al-4.28Cu-1.33Li-0.40Mg-0.30Ag-0.14Zr合金单级和双级时效组织与性能的影响。拉伸结果表明,对于190℃/(3~7)h的单级时效处理,3%拉伸预变形可以提高拉伸强度56~75 MPa,时效时间延长,预变形提高强度的效果大幅度降低。3%拉伸预变形可以使得190℃/7 h+100℃/24 h双级时效样品的强度提高81 MPa,达到748 MPa。透射电镜观察结果表明,190℃/7 h单级时效态样品对应的组织主要为T_1和θ′相,还有少量S′相;190℃/7 h+100℃/24 h双级时效态样品在190℃/7 h时效组织基础上析出了大量δ′相;而在190℃/7 h+100℃/24 h双级时效前施加3%拉伸预变形则极大地促进了T_1相和θ′相的析出,从而大幅度提高合金抗拉强度,而δ′相的析出受到抑制。
The effect of one⁃step and two⁃step aging treatment with 3%pre⁃strain at room⁃temperature on the microstructures and properties of Al⁃4.28Cu⁃1.33Li⁃0.40Mg⁃0.30Ag⁃0.14Zr alloy was investigated by using tensile testing and transmission electron microscopy(TEM).The tensile testing results show that the 3%pre⁃strain prior to one⁃step aging treatment at 190℃/(3~7)h can increase the tensile strength by 56~75 MPa.However,this effect will be greatly decreased with the prolongation of the aging time.It is found that the 3%pre⁃strain prior to two⁃step aging treatment at 190℃/7 h+100℃/24 h can increase the strength of the alloy by 81 MPa to 748 MPa.The TEM observation shows that alloy sample after one⁃step aging treatment(190℃/7 h)are dominated by T1 andθ′phases with a small amount of S′phase in the structure.And two⁃step aging treatment at 190℃/7 h+100℃/24 h brings a large precipitation ofδ′phases in the structure based on the previous aging treatment.Furthermore,3%pre⁃strain prior to two⁃step aging treatment at 190℃/7 h+100℃/24 h can greatly promote the precipitation of T1 andθ′phases,leading to the tensile strength greatly increased,but the precipitation ofδ′phase is inhibited.
作者
魏辽
刘志义
于迪尔
颜鹏飞
WEI Liao;LIU Zhi-yi;YU Di-er;YAN Peng-fei(China Petrochemical Corporation Engineering Research Institute,Beijing 100101,China;School of Material Science and Engineering,Central South University,Changsha 410083,Hunan,China)
出处
《矿冶工程》
CAS
CSCD
北大核心
2021年第1期106-109,113,共5页
Mining and Metallurgical Engineering
基金
国家重点研究与发展计划项目(2016YFB0300900)。
关键词
超高强铝合金
铝锂合金
时效
预变形
ultra⁃high strength aluminum alloy
aluminum lithium alloy
aging
pre⁃strain
