Mechanism to Reduce the Porosity during Argon Arc Welding of Aluminum Alloys by Changing the Arc Angle

Senchang Chen,Ping Zhang,Yanhui Chi,Yusheng Shi

doi:10.3390/met10091121

Abstract

A mechanism to reduce the porosity by changing the arc angle during aluminum alloy welding was studied. Industrial computed tomography was used to scan the welds with different arc angles, and the scanned model was processed by a specific software package to obtain the digital size and position of weld pores. The forces acting on the pores in the molten pool explained the test results that the number of pores decreases and the average size increases. As the inclination angle of the arc increased, the vertical component that prevented the bubble from rising decreased, and the horizontal component that pushed the molten metal flow and promoted the nucleation and growth of the bubbles increased. A horizontal movement during the droplet transition as the arc inclination was produced, which was conducive to the growth and overflow of bubbles. The theoretical analysis and temperature field measured by a far-infrared with different torch angle showed that when the arc was tilted from 0, the shape of the molten pool changed from the circle to the ellipse. The long axis of the ellipse increased as the bevel angle of the arc increased. This showed that the molten metal existed a longer time for the bubbles to escape from the molten pool when the angle of the arc increased. The paper provides fundamental insights into a mechanism for porosity reduction during the welding of Al alloys.

Highlights

Defects in welds such as pores are important factors that determine weld quality [1,2,3]
Another way is to reduce the gas composition in welding materials and base materials that go into the molten pool [8]
The object of this study is to investigate mechanisms to reduce the porosity during argon arc welding of aluminum alloys by changing the arc angle

Summary

Introduction

Defects in welds such as pores are important factors that determine weld quality [1,2,3]. One way of reducing weld pores is to reduce the content of gas components in the molten metal. Specific measures include increasing the protection of the molten pool and arc, such as improving the protection of the molten pool by increasing the pressure of a protective gas [7]. Another way is to reduce the gas composition in welding materials and base materials that go into the molten pool [8]

Results

Discussion

Conclusion