Homogenized Al-Mg series aluminum alloy weld microstructure laser welding method

Abstract

The invention provides a homogenized Al-Mg series aluminum alloy weld microstructure laser welding method. The homogenized Al-Mg series aluminum alloy weld microstructure laser welding method comprises the following steps that (1), pre-welding polishing is carried out, wherein a weld center area is firstly mechanically ground, oxide skin on the weld surface is taken out, and acetone is used for wiping oil stains or other impurities; (2), pre-welding parameter adjustment is carried out, wherein a laser head of a laser device is aligned to the place, needing to be welded, of a workpiece, and theheight is adjusted; and (3), waveform welding is carried out, wherein the position needing to be welded is welded, protective gas is used for protection, laser beams advance in the weld direction inparallel, in the advancing process, a galvanometer is used for making the oscillating laser beams symmetrically move back and forth on the two sides in the welding direction, and the light spot motiontrajectory is a square wave path. In the welding process, oscillating of the laser beams can agitate a molten pool and delay solidification in the molten pool, Mg elements in the weld are uniformly distributed, the beta phase (Mg2Al3) is uniformly precipitated, the weld microstructure homogenization is achieved, and the weld mechanical properties are improved.

Description

technical field [0001] The invention belongs to the field of welding technology, and relates to a laser welding method for homogenizing the welding seam structure of an Al-Mg series aluminum alloy. Background technique [0002] Al-Mg series aluminum alloy has the characteristics of high specific strength, good plasticity, corrosion resistance and excellent processing performance, and is widely used in molds, ship plates, ship shells, fuel storage tanks and other structures. This type of aluminum alloy is mainly solid solution strengthened by Mg atoms and work hardened. [0003] Laser welding has the advantages of high energy density, small heat input, large penetration with the same heat input, small heat-affected zone, small welding deformation, fast welding speed, and convenient automatic welding. It is increasingly used in the welding field. However, during the welding process of aluminum alloy, due to the characteristics of high heat transfer coefficient of aluminum all...

AI Technical Summary

Problems solved by technology

[0010] Post-weld heat treatment usually takes a long time, generally more than 10~15 hours, and the efficiency is low

Moreover, the heat treatment temperature of Al-Mg aluminum alloy is generally about 460°C, maintaining high temperature requires a lot of energy loss and increases the cost

At the same time, due to the limitation of the size of the heat treatment device, the heat treatment process cannot be realized for large structural parts

Images