How To Weld Aluminium

Last Updated on by

Aluminium soldering portrays some distinctive challenges, particularly as regards chemistry and crack sensibility compared to welding steel or other common materials. Aluminium welding requires certain special procedures in many situations.

Essential considerations for soldering the material include the right filler metal collection, proper storage and thorough cleaning of the material and right welding techniques.

The preference for the aluminium soldering method depends on the precise application criteria and the capabilities of the welder to carry out the manufacture. The methods are explained thus:

TIG Soldering Or Welding

The main method of welding aluminium is by the aid of tungsten inert gas (TIG). The aluminium working part takes up a lot of heat for a long time but can maintain it for a long time. It is useful to keep the aluminium workpiece from being overheated by a welding maker with the current control.

Thin aluminium and thicker copper plates can be exposed via TIG welding. Since a different filler rod requires TIG welding, the solderer will choose a soldering rod with an alloy which is as similar as possible to that of the working pieces.

MIG Soldering Or Welding

Appropriately welded aluminium should be used with metal inert gas ( MIG). Either spray arc welding or pulse soldering approaches should be used and will be determined before picking a welder. The inverter power supplies are required for pulse welding and for spray arc welding constant current and constant voltage machines can be used.

Due to the required fire, MIG soldering is better suited for smaller gages of aluminium panels. 100% argon is ideally suited to MIG aluminium welding when using a blinding flame. In order to create a high-quality weld, the welder must select a soldering wire or rod with the same alloy as the workpieces.

Torch Soldering Or Welding

Aluminium can be supplied by a torch fueled by air, although it is much harder to weld than MIG and TIG. The flame applied to the workpiece with the torch is difficult to regulate and burn when making use of a source of light such as a torch. Aluminium torch soldering requires a skinny welder which controls the torch and the filler rod adequately.

Cleaning Aluminum Before And After Work

Regardless of which form which solder is used to manufacture an aluminium solder, the components must be incredibly clean before welding starts. Aluminium oxide has a melting point much higher than aluminium foundation, meaning that oxides on the workpiece surface can lead to inclusions in the solid metal, which can decrease the total strength and appearance of the solid. Cleaning workpieces by chemical gravure or mechanical cleaning with a wire brush can be performed.

Welding Aluminum Challenges

Aluminium welding and important best practices for dealing with them pose some common challenges. The two largest differences in welding aluminium compared to steel represent thermal conductivity and problems with porosity. In liquid, aluminium hydrogen is easily soluble.

The hydrogen becomes removed and can be retained in solution as filler and aluminium base metal become molten during the welding process. If the substance is solidified, hydrogen can no longer be kept in a homogeneous combination. Hydrogen forms bubbles, which are caught in the metal and cause porosity.

Wash the base material carefully before welding to remove grease, debris, waste to humidity. This ensures the best performance and reduces porosity chances. The presence of hydrogen in aluminium soldering, contrary to steel, does not cause cracking. However, a hazard to aluminium is hot cracking that can happen when the solder solidifies.

Good Chemistry is the remedy for this. If a problem is hot cracks, refer to the selection chart of the filler metal in aluminium to find the best filler metal to solve the problem. The fact that aluminium is five times more thermally conductive than steel is another challenge.

The cool areas of the base metal tend to extract heat from the soldering pool and this may allow inadequate solder penetration. Owing to this improvement in thermal efficiency for soldering, aluminium takes much more heat than steel.

Filler Alloy Choice

When choosing a filler metal for aluminium, it is important to use a selection chart. Depending on the welding characteristics of the application, every combination of aluminium designations has recommended filler metal options.

The diagram includes eight main features of various welding applications: crack resilience, strength, ductility, resistance to corrosion and high temperature, anodisation colour, post solder therapy and tug-of-the-board therapy. In evaluating the needs of the end product, the most critical characteristics can be determined.

Select a filler metal that best suits the required characteristics within the specific application. The high service temperature of 150 to 350 degrees Fahrenheit with aluminium is important to note. The aluminium chart contains these and other characteristic definitions.

A filler metal choice device like this is an option. You can find the same information in the app on the entire selection chart, but only filler metal for the selected base materials. The right collection of filler metal is also necessary. For starters, if 6061 aluminium is used as the base material, 4043, 5943, and 5356 are good choices for filling metals.

Wire or gas-type tungsten arc solder can reduce the porosity and improve soldering and fluidity of the puddle, while 5356 can be tougher and more resistant.

Best Ways To Practice

In addition to selecting the most appropriate filler metal for the use, some of the key best practices can also help to ensure success with aluminium welding. Some of which are:
Don’t incorporate: Although steel is usually used in a fabric technique, it should not be used in aluminium. Use a bead to ensure proper penetration and fusion instead. If you are using GMAW aluminium, make sure you use an increased heat input and a quick speed in the puddle.

Tidy the metal: To remove the oil, dirt, residues and moisture, carefully clean the base material before welding. This contributes to the best results and lowers porosity chances. The hydrocarbon can be removed well from the material surface by an acetone or aluminium cleaner. Do not blast off the soldering joints by compressed air when cleaning, because dust and oils will be polluted if machines for the shop are employed.

Let the coating of oxide down: After cleaning, remove the aluminium oxide layer before welding by means of a brush made from steel one new or used only on aluminium. Aluminium oxide has a much higher than the aluminium melting point, as mentioned before. It is an insulating material that can cause problems in the arch starting and requires very high heat to weld the oxide layer. The base material and porosity can be burned because the oxide layer tends to hold moisture.

Properly store it: In preventing porosity, storage practices for base materials and filler metals also play a role. Where possible, store indoor aluminium sheets. When stored outside, the plates are to be positioned vertically and not on top of each other in order to prevent the trapping of water and thus to form a thicker, hydro-oxidized layer of aluminium.

Before soldiering preferably the day before bringing in materials and filler metals stored outside or in an air-conditioned area of the building to the shop to stabilize the metal tempers and to prevent moisture in the air from creating condensation on the aluminium.

The consumables should be explored: Aluminum soldering problems may occur from the consumables, particularly when using GMAW. In order to reduce the risk of porosity, use new or well-connected gas lines and tubes to make sure that all tight tubing connections do not pull air.

The right liners and drive rolls should also be used. Plastic coatings and entry directions can provide benefits over aluminium soldering liners in steel as the soft aluminium wire is abradable through the drive mechanism and liners by metal or brass inlet guides and steel liners. This can lead to wire cuts that obstruct the liner and cause feeding problems. Similarly, aluminium U-groove drive rolls are standard because other kinds of drive rolls may break down or distort the wire.

Temperature monitoring: To find the proper preheating temperature ranges, consult an aluminium metal filler guide or code. Prior heating can be done to reduce section size thermal effects when thick base metals are welded or variations in thickness, except for the aluminium used to hold preheating to a minimum.

The preheated or inter-passing temperatures above 250 Fahrenheit should not be subject to heat-treatable base-metal and base-metal of 5xxx series that contain more than 3per cent magnesium for more than 15 minutes. During high temperatures, the time spent can reduce material strength and contribute to cracking.


Chemistry often presents itself with the challenges of welding aluminium. The correct match of base material and filler metal can achieve success and minimize problems. The best practices for soldering aluminium are also important and understand that aluminium welding techniques and standards practices are very distinct from soldering steel. This write-up tried to do justice in explaining how aluminium can be weld. With this understanding, myths and ignorance surrounding aluminium welding are cleared and you can go ahead and have your aluminium weld properly.

Leave a Comment