铝合金厚板激光扫描填丝焊接气孔抑制

采用光纤激光对8 mm厚度的7A52铝合金板材进行对接焊接试验，分析焊缝上下组织及性能差异. 采用能谱仪（EDS）分析焊缝不同区域合金元素的烧损情况，并对焊缝和母材分别进行拉伸试验，测量焊缝显微硬度.结果表明，焊缝上部区域的显微组织比下部区域小，焊缝上部Mg，Zn 元素含量低于下部边缘；焊缝上部中心的显微硬度高于下部中心，焊缝上边缘的显微硬度小于下边缘； 焊接接头以韧性断裂为主要特征，抗拉强度为325 MPa，为母材的65.9%. 焊缝抗拉强度的降低与Mg，Zn元素的烧损、焊接应力、气孔缺陷等因素密切相关.

Recent developments in advanced aircraft aluminium alloys

Fiber laser bean welding was used to fabricate 8 mm 7A52 alloy plates by butt welding. Microstructures and mechanical properties of the welded joint were investigated. Energy disperse spectroscopy (EDS) was used to measure the burning loss of alloy elements in different regions of the weld. The tensile strength and microhardness of the weld were also measured. The results showed microstructures in the upper area were smaller than that in the lower area, the content of Mg and Zn in the upper part of weld was lower than that in the lower edge. Microhardness in the upper center was higher than that in the lower center, while microhardness at the upper edge was smaller than that at the lower edge. A ductile fracture was observed as the key characteristic for the welded joint, and the tensile strength was 325 MPa, of 65.9% of base metal. The decrease of the tensile strength was caused by the burning loss of Mg, Zn, welding stresses and porosity defects.