(西北工業(yè)大學焊接教研室， 西安 710072)
摘 要: 采用焊縫合金化手段，通過設計新型焊絲向焊縫中添加Li 、Zr和Ce等合金化元素，研究了2090Ce 稀土鋁鋰合金焊縫金屬的熱裂紋敏感性；探討了合金元素對接頭力學性能的影響及作用規(guī)律；進而研究了適用于焊接 2090Ce 合金的焊絲合金成分。試驗結(jié)果表明，向焊縫金屬中添加適量的合金元素Li、Zr和Ce，能夠細化晶粒；增加焊縫中的共晶數(shù)量并改善其分布形態(tài)，從而有助于降低焊縫金屬的熱裂紋敏感性。另外，適量的Li、Zr和Ce等合金元素還能夠在不降低接頭塑性的同時，明顯改善接頭的強度；但Li 和Ce含量過多則會對接頭性能，特別是塑性造成損害。所設計的焊絲材料能夠適用于焊接2090Ce稀土鋁鋰合金。
關鍵字: 2090Ce鋁鋰合金 焊縫合金化 焊接接頭 熱裂紋敏感性 力學性能
（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
