铝锂合金钎焊接头断口组织与性能

采用金相显微镜、扫描电镜、硬度计等测量方法,观察分析了铝锂合金钎焊前后母材和钎焊接头的显微组织变化,通过分析测试钎焊接头的显微硬度和断口微区的化学成分,研究分析了钎焊接头强度的变化规律.结果表明,焊后母材中的强化相由质点转变为板条状;氮气保护条件下,钎焊接头未见气孔、夹杂、裂纹等缺陷,钎焊接头存在一定的扩散区,从而有效地提高了钎焊接头的强度;无氮气保护的条件下,钎焊接头有大量的缺陷存在,这些缺陷的存在严重影响了钎焊接头的强度.

Fracture microstructures and properties of Al-Li alloy brazed joints

Microstructures of base metal and brazed joints were analyzed using metallographic microscope, SEM and microhardness instrument,and the changing rule of strength of brazed joints was studied by testing microhardness of brazed joints and chemical composition of fracture micro-section. The results show that shape of reinforcing phase of base metal are changed from particle to strip after brazing; there are few defects such as gas pores, slag inclusions, cracks and so on in brazed joints with N_2 atmosphere, which improves mechanical properties of brazed joints effectively, however there are many defects in brazed joints without N_2 atmosphere, which reduces mechanical properties of brazed joints seriously.