Microstructural evolution and mechanical properties of a new Al-Cu-Li-X alloy at different solution temperatures
来源期刊：Rare Metals2021年第3期
论文作者：Long Zhang Zi-Qiao Zheng Jin-Feng Li 李俊江 Yong-Lai Chen Xu-Hu Zhang
文章页码：635 - 642
摘 要：The micros tructural evolution and mechanical properties of a new Al-3.8 Cu-1.2 Li-0.4 Mg-0.4 Zn-0.4 Ag-0.3 Mn-X alloy treated at different solution temperatures were investigated.The grain size was measured in optical micrograph（OM）.The residual particles and the major precipitates were identified by electron probe microanalysis（EPMA）,scanning electron microscopy（SEM） and transmission electron microscope（TEM）,respectively.The results show that the peak strength appears at 530℃/1 h+T6（165℃/20 h） and the values are 566.2 MPa（tensile strength） and 538.2 MPa（yield strength） with the elongation of 6.5 %.The strength of the alloy increases rapidly with the amount of the precipitates T1 and θ’ increasing when the solution temperature is530℃.The increase in density of precipitates is resulted from the residual particles Al2 Cu,and particles enriched with Cu,Mg,Zr and Ag dissolve into matrix gradually with the solution temperature increasing.Finally,the number of precipitates decreases and part of the grain boundary weakens with a further increase in solution temperature from 540 to 550℃,leading to a decline of strength.
Long Zhang1，Zi-Qiao Zheng1，Jin-Feng Li1，Cheng-Yu Tan1，Yong-Lai Chen2，Xu-Hu Zhang2
1. School of Materials Science and Engineering,Central South University2. Aerospace Research Institute of Materials and Processing Technology
摘 要：The micros tructural evolution and mechanical properties of a new Al-3.8 Cu-1.2 Li-0.4 Mg-0.4 Zn-0.4 Ag-0.3 Mn-X alloy treated at different solution temperatures were investigated.The grain size was measured in optical micrograph（OM）.The residual particles and the major precipitates were identified by electron probe microanalysis（EPMA）,scanning electron microscopy（SEM） and transmission electron microscope（TEM）,respectively.The results show that the peak strength appears at 530℃/1 h+T6（165℃/20 h） and the values are 566.2 MPa（tensile strength） and 538.2 MPa（yield strength） with the elongation of 6.5 %.The strength of the alloy increases rapidly with the amount of the precipitates T1 and θ’ increasing when the solution temperature is530℃.The increase in density of precipitates is resulted from the residual particles Al2 Cu,and particles enriched with Cu,Mg,Zr and Ag dissolve into matrix gradually with the solution temperature increasing.Finally,the number of precipitates decreases and part of the grain boundary weakens with a further increase in solution temperature from 540 to 550℃,leading to a decline of strength.
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