(1. 中南大学 材料科学与工程学院, 长沙 410083;
2. 航天材料及工艺研究所, 北京100076;
3. 东北轻合金有限责任公司, 哈尔滨 150060)
摘 要: 分别采用Al-Mg-Zr和Al-Mg-Zr-Sc合金焊丝为填充材料， 对2 mm厚的Al-Mg-Sc合金薄板进行惰性气体保护焊接， 然后对两种焊接接头的显微组织和力学性能进行对比研究。 结果表明： 采用两种焊丝焊接的Al-Mg-Sc合金薄板的焊接接头强度系数均大于0.9。 但采用Al-Mg-Zr-Sc合金焊丝为填充材料时， 焊缝晶粒组织明显细化， 熔合区形成的细小等轴晶层提高了基材与焊缝填充材料的结合力， 焊接接头的屈服强度比采用Al-Mg-Zr合金焊丝为填充材料时提高了100 MPa， 显著提高了Al-Mg-Sc合金焊接构件的许用强度, 因此焊接Al-Mg-Sc板材更宜采用Al-Mg-Sc-Zr焊丝。
关键字: 铝镁钪合金焊接; 焊丝; 熔合区; 焊接接头； 组织与性能
（ 1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Institute of Spaceflight Material and Technology, Beijing 100076, China;
3. Northeast Light Alloy Co. Ltd., Harbin 150060, China）
Abstract: The Al-Mg-Sc alloy sheets with 2 mm thickness were welded by manual labor inert-gas arc welding method, the mechanical properties and microstructures of Al-Mg-Sc alloy weld joints filled with Al-Mg-Zr or Al-Mg-Zr-Sc welding wires were studied comparatively. When the Al-Mg-Zr-Sc welding wire was used as filling material, the grains of welding seam were refined obviously, and the weld joint was greatly strengthened by forming of fine equiaxial grains layer in fusion zone. The results show that, the coefficients of welded joints are both greater than 0.9, but the yield strength of weld joint filled with Al-Mg-Zr-Sc welding wire is greater 100 MPa than that of filled with Al-Mg-Zr welding wire. It indicates that the Al-Mg-Zr-Sc welding wire is the best alteration of filling materials to weld of Al-Mg-Sc alloy.
Key words: weld of Al-Mg-Sc alloy; weld wire; fusion zone; weld joint; microstructure and properties
