Weld cracking and joint strength of 2219 by MIG welding

Abstract

Weldability of Al–Cu series alloy 2219 with MIG process was investigated in comparison with that of Al–Cu-Mg series alloy 2024. On weld cracking sensitivity, 2219 is superior to 2024 and as for the combination with filler metal, the decrease in Mg content in weld metal causes crack resistance to increase. And a liquation cracking in heat-affected zone was easily initiated in the case of Mg contents more than 1.6 mass% and Cu/Mg (ratio in mass%) less than 1.8 in weld metal. Welded joints were mostly fractured in weld metal even with reinforcement during tensile testing, so the intensification of weld metal is directly connected to the improvement in joint strength and fractured mode. The results of the investigation of correlation between the strength and chemical composition in weld metal revealed that the joint strength increased with an increase in magnesium and manganese but encouraged the weld cracking simultaneously. However, the author has also found that silicon was available for decreasing weld crack and the possibility of consistency with joint strength and crack resistance by control of these contents of Mg, Mn, and Si.

Keywords:

• 2219
• 2024
• weld cracking
• tensile strength
• arc welding