(西北工业大学焊接教研室， 西安 710072)
摘 要: 采用焊缝合金化手段，通过设计新型焊丝向焊缝中添加Li 、Zr和Ce等合金化元素，研究了2090Ce 稀土铝锂合金焊缝金属的热裂纹敏感性；探讨了合金元素对接头力学性能的影响及作用规律；进而研究了适用于焊接 2090Ce 合金的焊丝合金成分。试验结果表明，向焊缝金属中添加适量的合金元素Li、Zr和Ce，能够细化晶粒；增加焊缝中的共晶数量并改善其分布形态，从而有助于降低焊缝金属的热裂纹敏感性。另外，适量的Li、Zr和Ce等合金元素还能够在不降低接头塑性的同时，明显改善接头的强度；但Li 和Ce含量过多则会对接头性能，特别是塑性造成损害。所设计的焊丝材料能够适用于焊接2090Ce稀土铝锂合金。
关键字: 2090Ce铝锂合金 焊缝合金化 焊接接头 热裂纹敏感性 力学性能
（Researching Group of Welding, Northwestern Polytechnical University, Xi'an 710072）
Abstract:Both hot cracking susceptibility of the weld metal and mechanical properties of the weldment of 2090Ce Al-Li alloy containing rare-earth cerium were investigated by means of weld alloying method through newly designed filler wire in which suitable amounts of alloying elements such as lithium, zirconium and cerium were added. The composition of the filler alloy appropriate for welding 2090Ce alloy was also discussed. The results revealed that the suitable addition of Li, Zr and Ce in weld may promote the refinement of solidification microstructure, increase of eutectic content and improve the distribution of eutectic. The improvement of microstructure leads to a considerable reduction of the susceptibility of hot cracking of weld metal as indicated by the transverse-varestraint test. Otherwise, the results show that the tensile strength of the weldment can be evidently improved while keeping constant plasticity. Nevertheless, excessive amounts of lithium and cerium in the weld metal may be harmful to the properties, especially plasticity, of the weldment. The results have also verified that the newly designed filler alloys are applicable for welding 2090Ce Al-Li alloy.
Key words: 2090Ce Al-Li alloy weld alloying weldment hot crack susceptibility mechanical properties
