TIG焊工艺对LD10铝合金接头气孔的影响

LD10铝合金是国内航天运载器推进剂贮箱的主要应用材料,通常采用钨极氩弧焊(TIG焊).气孔是铝合金熔焊接头中的常见缺陷,文中对5.5 mm厚的LD10铝合金进行了4种不同工艺条件的TIG焊接,对比研究了4种工艺接头的气孔问题.结果表明,LD10铝合金采用TIG焊时,容易产生气孔,其中两面三层焊接头X射线检测出的不合格焊缝相对较多;对于合格焊缝中的微气孔而言,两面三层焊较少,其次是两面两层焊和单面两层焊,单面单层焊最多,它们的气孔率分别为0.90%,2.28%,2.53%,3.28%.焊缝气孔较多时,在接头横向拉伸试验中裂纹容易从气孔启裂.

Influence of TIG welding parameters on porosity in LD10 aluminum alloy joint

LD10 aluminum alloy is mainly used in domestic aerospace vehicle propellant tank and mostly joined by TIG welding,and pores often appeared during fusion welding of aluminum alloy. This paper conducted TIG welding of 5.5 mm thick LD10 aluminum alloy plates with different welding parameters and calculated the porosity in the joints. The experimental results show that LD10 aluminum alloy joints made by TIG welding were prone to high porosity. The joints produced by double-faced three-pass welding technique had a higher unqualified rate after X-ray detection,but contained fewer micro-pores in the qualified ones. And micro-pores were much more easier to form in robot automatic welding than in manual welding. Porisity of the welds was 3.28%,2.53%,2.28% and 0.9%,respectively. During tensile test,cracks often generated at the pores in joints with high porosity.