Titanium Alloy A-TIG Welding Technology and Its Characteristics

A-TIG welding technology is a process method where an active flux is applied to the surface of the workpiece to be welded before the TIG welding is carried out. Compared with the conventional TIG welding process, the penetration ability of the arc in the A-TIG welding process of titanium alloys is significantly enhanced, and the heat input, welding deformation and stress are reduced. When welding products with the same specifications, under the same welding current conditions, single-pass welding without bevels or significantly reducing the number of weld layers can be achieved, thereby improving welding productivity and product quality and reducing costs by several times.

In addition, the active flux can significantly reduce the weld porosity defects during argon arc welding, thereby directly improving the fatigue performance of the welding joint and the welding structure. Tests show that the fatigue limit of the A-TIG welded joint of Ti-6Al-4V titanium alloy is 16% higher than that of conventional TIG welding, reaching 90% of the base material. Currently, the argon arc welding technology with active flux for titanium alloys has developed into a new advanced connection manufacturing technology to ensure the quality of weapons equipment, improve processing efficiency and reduce costs.

The existence of the film limits the conduction cross-section of the arc, causing the arc to contract; secondly, due to the active flux layer covering the surface of the titanium alloy material before welding, during the arc conduction process, only the arc heat melts the active flux and titanium metal, and the liquid titanium successfully squeezes away the weld film, so that the successful conduction and stable combustion of the arc can be achieved. Due to the good wettability between the molten active flux and the liquid titanium, the weld film is less likely to be squeezed away. The less it is squeezed away, the narrower the weld seam, the more concentrated the heat flow of the arc, and the deeper the penetration depth; third, during A-TIG welding, the active flux molecules vapor enter the arc atmosphere, increasing the thermal conductivity of the plasma in the arc column, thereby causing the arc to contract; fourth, the arc heat decomposes and ionizes the active flux and enters the peripheral space of the arc, capturing the electrons outside the arc to form negative ions, reducing the voltage in the peripheral space of the arc column, and thus causing the arc to contract. It is precisely because of the synergy of these several aspects that the welding arc in the A-TIG welding process undergoes significant contraction, the current density of the arc column increases, and the welding penetration depth increases.