Aluminum is a material that is often used in the transportation industry because it has a low density, high strength, and good corrosion resistance. The transport structure requires connection to achieve a form as designed. The joint process usually uses a welding process because welding has good metallurgical properties, superior mechanical properties, and low cost. Aluminum welding generally has disadvantages. One of these weaknesses is the formation of porosity, which will affect the welded joint’s mechanical properties, so the discussion of porosity in aluminum welded joints is critical. This paper attempts to provide an overview of the formation mechanisms and types of porosity defects in aluminum alloys’ welding method. A brief description of the effect of the environment on porosity defects, the causes of porosity formation, the impact of porosity, and how to reduce porosity in aluminum welding will be discussed. In conclusion, the formation of porosity in the welding process is due to dissolved hydrogen in the weld metal, air/bubbles from the welding process, filler/filler wire, and the environment welding influence. The impact of porosity can cause cracks in welded joints, decreased ductility, and failure of fatigue. This study’s results can be used as a basis for analyzing the relationship between the welding environmental parameters and the welding defect porosity.

A review porosity in aluminum welding

A 3D arc-droplet-molten pool integrated model of Al alloy GMAW process: Heat transfer, fluid flow and the effect of external magnetic field

Study on synchronous induction of arc plasma by laser in laser-double TIG hybrid welding

Arc welding processes are still widely used in manufacturing industry. To further improve the arc welding efficiency and the joint quality, secondary energy field/source is usually applied to assis...

Auxiliary energy-assisted arc welding processes and their modelling, sensing and control

In this paper, a self-designed cusp external magnetic field (EMF) was employed to assist the two-electrode TIG (T-TIG), and its common conductive channel characteristics were aimed to optimize the energy distribution of T-TIG. The influences of the cusp EMF on arc morphology, arc plasma information, and arc pressure of T-TIG were respectively analyzed based on a high-speed camera, spectrograph, and pressure sensor. The results showed that the cusp EMF could compress T-TIG in the direction parallel to the array of two electrodes of T-TIG, and thus, a common conductive channel with stronger brightness and higher stiffness was obtained. Besides, by applied cusp EMF, the electron temperature and electron density of the common conductive channel of T-TIG were increased, and in the radial, the distributions of electron temperature and electron density of T-TIG were more concentrated. Under the condition of welding current of 40 A + 40 A, the electron density on the central axis of T-TIG could be increased by 16% by applied cusp EMF with a 30 A excitation current. In addition, the enhanced common conductive channel characteristics of T-TIG by the cusp EMF caused the arc pressure on the central axis of T-TIG to be increased by 14%, which was beneficial to improve the weld penetration.

ShouCheng Luan

Papers

Numerical analysis of arc and droplet behaviors in gas metal arc welding with external compound magnetic field