A new approach was developed to improve strength of Al-Cu-Mg alloy laser welded joints that typically within 61–90 % of that of the base metal due to a change in the microstructure and phase composition of the weld one. This result was achieved by optimization of post weld heat treatment (PWHT) included quenching and subsequent artificial aging. For the first time, the spatial distribution and evolution of the phase composition were studied at all PWHT stages using high-resolution scanning electron microscopy and synchrotron X-ray analysis. It was found that the Al-Cu-Mg solid solution was homogenized, as well as the S(Al₂CuMg) strengthening and (partly) θ(Al₂Cu) phases were formed. After PWHT, ultimate tensile strength was 428 MPa, yield strength was 302 MPa, and elongation was 19.6 %, which were 99 %, 98 % and 95 %, respectively, of those of the base metal.

开发了一种新方法来提高Al-Cu-Mg合金激光焊接接头的强度，由于焊接结构和相组成的变化，其强度通常在母材强度的61-90％之内。通过优化焊后热处理（PWHT）（包括淬火和随后的人工时效）可以达到此结果。首次使用高分辨率扫描电子显微镜和同步加速器X射线分析研究了所有PWHT阶段的相组成的空间分布和演变。发现Al-Cu-Mg固溶体以及S（Al ₂ CuMg）强化和（部分）θ（Al ₂形成Cu）相。PWHT后，极限抗拉强度为428 MPa，屈服强度为302 MPa，伸长率为19.6％，分别是母材的99％，98％和95％。