Tips of TIG welding for aluminium alloy

Author : Shanon Adell | Published On : 04 Mar 2021

TIG welding (tungsten arc welding) of light weight aluminum alloy is to make use of a huge quantity of warmth produced by the formation of an arc in between tungsten electrode as well as the work surface to thaw the aluminum material, and afterwards fill the welding cable to acquire a firm welding joint. The tungsten electrode as well as weld location are protected by inert gas from the nozzle to prevent reaction between the weld location and also the surrounding air.

TIG welding is suitable for welding aluminum alloy sheet with a density of less than 3mm, its contortion is substantially much less than gas welding as well as hand arc welding. A/C TIG welding cathode can efficiently clean up the oxide movie, without the use of flux to stay clear of welding residue and also slag corrosion. Its joint form is not restricted, will certainly produce good joints forming and also bright appearance. The erosion of the welding part by argon gas sped up the cooling, boosted the structure and efficiency of the joint, appropriate for all-position welding.

Air Conditioner TIG welding as well as AC pulsed TIG welding are the most typically utilized techniques for welding aluminum alloys, adhered to by DC reverse TIG welding. A/C welding of aluminum alloy can accomplish the most effective suit in the present carrying ability, arc control and also arc cleansing. When direct existing connection (electrode connection), warmth is generated externally of the workpiece and also creating deep infiltration. Although seldom made use of DC reverse connection (electrode favorable) TIG welding technique to weld light weight aluminum, however this technique is revealed effectively in continuous welding or repair work welding thin-walled warmth exchanger, pipe density below 2.4 mm, will provide a good melting depth and also arc simple to regulate.

( 1) Tungsten electrode

Tungsten is the metal with the highest melting point.

Tungsten has a strong electron discharge ability at heat. When the tungsten electrode is added with the oxides of trace rare earth elements such as thorium, cerium, zirconium, etc., the electron discharge is considerably lowered and also the current bring capacity is boosted. Throughout TIG welding of aluminum alloy, tungsten electrode is mostly used to conduct current, sparks arc and also maintains arc burning usually. Commonly used tungsten electrode materials include pure tungsten, thorium tungsten and cerium tungsten.

Welding process parameter

In order to obtain exceptional weld forming and also quality, according to the thickness of aluminum alloy plate, the welder must initially select tungsten electrode diameter and shape, welding cord size, securing gas and also flow rate, nozzle aperture, welding current, arc voltage and welding speed, and after that sensibly readjust the welding process criteria according to the actual welding effect. The major technological specifications of hands-on TIG welding of light weight aluminum alloy consist of existing, electrode, securing gas circulation price, tungsten electrode extension size, distance in between nozzle and work surface, and so on. But for automated TIG welding, the arc voltage (arc size), welding speed as well as wire feeding rate are the most vital factors.

Parameters of TIG light weight aluminum alloy welding:

1) Nozzle aperture and safety gas flow.

The nozzle aperture of aluminum alloy TIG is 5 ~ 22 mm, as well as the safety gas circulation is normally 5 ~ 15L/min.

2) Tungsten electrode expansion size and also the range in between nozzle and work surface.

Tungsten extension length of butt weld is normally 5 ~ 6, fillet weld is normally 7 ~ 8. The range from the nozzle to the workpiece is usually about 10 appropriate.

3) Welding current.

This depends upon welding voltage, density, joint type, welding area as well as welder skill.

Guidebook TIG welding making use of A/C power supply, welding thickness of much less than 6 light weight aluminum alloy, the optimum welding current can be established according to the electrode size D according to the formula I= (60 ~ 65) D. The arc voltage is mostly determined by the arc size, which is usually around equivalent to the tungsten size.

4) Welding speed.

TIG welding of aluminum alloy need to take on much faster welding speed in order to decrease contortion. The general manual TIG welding rate is 8 ~ 12m/h; In automatic TIG welding, the welding rate is usually unchanged throughout the welding process after the parameters are established,.

5) The dimension of the aluminum alloy welding cord.

It is normally figured out by aluminum plate density and also welding existing, as well as the diameter of the welding cord is proportional to them.