Effect of laser power on the grain morphology and microhardness of dual laser-beam bilateral synchronous welded 2219 aluminium alloy T-joint

ABSTRACT

Dual laser-beam bilateral synchronous welding (DLBSW) technology has been widely used in the connection of skin-stringer T-joint. In this study, DLBSW technology was performed to fabricate T-joint of 2219 aluminium alloy. Furthermore, the effect of laser power on grain morphology and microhardness of the T-joint was investigated. The microstructure of different parts was observed and the grain size was quantitatively analysed. The results show that the grain quantity and microhardness of the welded joint are increased significantly as the welding heat input increases. It is found that the influence of laser power on the grain size at the edge of the weld seam is greater than that in the centre of weld. Besides, the microhardness of the non-dendritic equiaxed zone decreases with the increase of laser power, which is caused by the decrease of Al element.

KEYWORDS:

• DLBSW
• 2219 aluminium alloy
• T-joint
• grain morphology
• microhardness
• laser power
• EQZ

Disclosure statement

No potential conflict of interest was reported by the author(s).

Funding details

The authors did not receive support from any orga-nisation for the submitted work.