Three types of laser beam oscillating welding were applied on 5A06 aluminum alloy sheets. The microstructure and mechanical properties of the welded joints were characterized. The formation and elimination mechanisms of welding pores during laser beam oscillating welding was investigated. The results showed that laser beam oscillating welding using linear, circular and infinity paths allow to reduce the porosity of the welded joint when compared to the joint produced without beam without oscillation. Among the three oscillating paths, the infinity mode was the best in terms of decreasing the porosity in the weld and increasing the tensile strength. The decrease in porosity of the fusion zone was associated with the weld shape and the decrease of the depth-to-width ratio of the weld due to the oscillation of the heat source. Laser beam oscillating welding applied to aluminum alloys can be of significant interest to industry to decrease porosity problems typically encountered during laser welding of these materials.

Laser beam oscillating welding of 5A06 aluminum alloys: Microstructure, porosity and mechanical properties

Ultrasonic assisted laser-MIG (melt inert-gas) hybrid welding is carried out in order to overcome the problems of high porosity, coarse crystal grains and poor mechanical properties of aluminum alloy welded joint. Continuous ultrasonic vibration of 0–200 W is applied during the laser-MIG hybrid welding. The effects of ultrasonic power on porosity, microstructures and mechanical properties of the weld are investigated. Experimental results indicate that with the increase of ultrasonic power, the porosity of the weld decreases first and then increases, and the joint microstructure is obviously refined. At the same time, ultrasonic vibration can increase the strength of the welded joint, which leads to the higher tensile strength of the joint and homogenizing the distribution of microhardness in the weld zone (WZ). Furthermore, the WZ strength increases with increasing ultrasonic power, which results in the transformation of tensile fracture position from the WZ to the heat affected zone (HAZ).

Effect of ultrasonic power on porosity, microstructure, mechanical properties of the aluminum alloy joint by ultrasonic assisted laser-MIG hybrid welding

Review on failure behaviors of fusion welded high-strength Al alloys due to fine equiaxed zone

Stainless steel is a widely used material in various industries such as aerospace, chemical processing and transportation. Tungsten Inert Gas (TIG) or Gas Tungsten Arc Welding (GTAW) process is ext...

Junshan Yao

Papers

The effect of TIG welding techniques on microstructure, properties and porosity of the welded joint of 2219 aluminum alloy