Titanium welding is increasingly popular and applied by the advantages of aesthetics and quality of the weld.
In the welding technique of titanium alloys, the weld is greatly influenced by the surface state of the weld edges and the fill metal. Products after heat treatment will form oxide and nitrite films that need to be cleaned by mechanical processing, sandblasting, shot blasting or chemical pickling.
For welding titanium and its alloys, tungsten electrodes and protective gases are the most common applications.
The process of welding titanium, titanium alloys or other heat-resistant metals should pay attention to limit welding intensity to limit overheating and heat affected areas. When welding titanium with non-melting electrodes, the welding intensity does not exceed the 300A threshold. This line can weld a non-beveled alloy plate line up to 3mm thick. When the thickness of the solder is large, the edge needs to be chamfered with an opening angle of 70 to 90 degrees. The gap between the edges is about 1.5 to 2mm. Applying multi-layer welding method and wire filling. In case of large thickness from 20 to 25mm, it should be chamfered with U shape.
During welding, hands should not oscillate to avoid protection from uninterrupted gas. Take care to keep the arc short and the electrode angle to about 90 degrees. Welding wire is supplied continuously during the welding process. When pausing, or finishing the welding process (even when the arc is turned off), the protective gas must be maintained. Applying mechanical welding will give welds a more stable quality than manual welding.
We can observe the effect of the shielding gas on the weld through the outside color. Silver-white welds corresponding to the quality of welded joints are guaranteed. Greenish yellow appearance is due to interrupted protection. And gray corresponds to poor protection. The quality of the weld is also assessed by weld hardness. If the weld is well protected, the hardness does not exceed the hardness of the base metal.
Electronic welding is also used for titanium welding, but it requires a high level of equipment and workmanship.
Titanium high-defusion welding technology is applied to produce important structures in important fields such as space, aircraft, rockets, etc.