Even for the most highly skilled welders, the process of welding aluminum parts can cause some difficulties. Most people wonder, “Can I weld aluminum?”
The process of welding aluminum requires conditions that are important to know about in order to make a weld quality and work on different projects.
Although the aluminum welding processes can be challenging, it is a skill that can be improved by gaining the necessary knowledge and practice.
To learn everything about aluminum welding, from welding methods to general tips for a successful job, read on!
Why Aluminum Welding Is Difficult
Aluminum is most commonly used in the manufacturing industry. This metal, together with a thin aluminum oxide layer, has important positive qualities: firstly, it is not prone to corrosion, secondly, it is lightweight and pleasing to the eye, and thirdly, it is the optimal material for many types of welds.
Nevertheless, the same characteristics that make this metal, like a thin aluminum oxide layer, attractive make it difficult to work with.
The complexity by which aluminum is welded: the material has a sensitive structure. The material is coated with a strong aluminum oxide layer. Weak and at the same time porous welds become when aluminum is molten and is exposed to impurities.
The degree of oxygen absorption by aluminum and its alloys is very high. At six hundred and fifty degrees Celsius, pure aluminum melts, while the aluminum oxide covering the metal melts without a weld pool at three thousand seventy-seven degrees or two thousand thirty-seven degrees Celsius.
The aluminum oxide must be removed from the metal because the temperature of the aluminum oxide is nearly thousand three hundred and seventy degrees more than the aluminum itself.
Aluminum burning is possible because has a lower machinability window when compared to other metals. Because aluminum is very conductive when its melting point is rather low, this problem arises.
Together with the difficulty in evaluating the progress of welding, this circumstance can cause aluminum to become increasingly difficult to work with.
Difficult Factors for Welding
In general, there are several of the most prevalent contributing factors that cause aluminum welding to become difficult.
Oxidation
As noted earlier, the aluminum oxide layer that is directly on the surface of the aluminum begins to melt at much higher temperatures than the aluminum material itself. A rather high temperature is required for this layer to begin to melt.
The welder is advised to be very careful to avoid holes in the aluminum underneath the aluminum oxide layer as a result of high temperatures.
Porosity
Note that a material such as aluminum can absorb more hydrogen in its molten form the faster it is heated. When the metal is quenched for the 2nd time, there is a separation of hydrogen. Eventually, the material may contain bubbles. These lead to the appearance of pores. In addition, the metal becomes quite weak.
Impurities
Due to the high degree of sensitivity of all aluminum alloy in the welding, there is a possibility that it will be contaminated by water, common dirt, or air in various ways. For example, you might consider air contamination.
Because the latter gets into the weld, aluminum can become heavily contaminated. This problem can occur because the shielding is not effective enough or the arc is too long.
The aluminum oxide layer causes some problems with the material: reducing the strength as well as ductility of aluminum, and the appearance of aluminum oxides on the welds – this has a certain impact on the appearance, as well as complicating the welding processes in three or more passes.
Hydrogen sources may be numerous: dampness within the electrode flow, dampness in the air, wet welds, etc. Given these reasons, it is important to completely clean the aluminum oxide layer from the part and ensure that it is properly stored before welding.
Thickness
The welding aluminum alloys is supposed to work with materials that have different thicknesses.
Welders need to understand how to prevent thin type material from burning through to ensure that the strongest weld is created, and welding specialists also need to know how to weld the thicker material as well as possible and according to regulations deep enough to create a strong weld.
Learning how to weld aluminum is easy, even though the process itself is complicated. Fortunately, it is possible to take advantage of techniques as well as means by which the unique qualities of aluminum can be applied.
If one clearly understands exactly how your favorite aluminum reacts, and in case these kinds of methods are used correctly, one can master the proper techniques.
Aluminum Welding Optimal Option
To weld a material like aluminum, it comes down directly to choosing the right aluminum welding process. Most methods, as well as means, are used directly for welding steel, but certain equipment, as well as technique, is needed directly for aluminum.
The aluminum should be cleaned as best as possible, in particular, a very thin aluminum oxide layer should be removed. As noted above, a big problem with aluminum alloy can be various contaminants. For this reason, it is necessary to ensure the quality preparation of the material.
The steps that, need to be carried out:
- Components such as water vapor, as well as soap, and grease must be removed from the surface of the aluminum alloy. For this purpose, it is recommended to use a solvent, such as acetone, or a weakly concentrated alkali solution, for example, a powerful soap.
- The use of a stainless steel wire brush (only for aluminum) is necessary to remove all aluminum oxides. In addition, you can use acid or alkali. Before starting the welding process, it is recommended that the material be thoroughly washed and then thoroughly dried so that not a single drop of water or aluminum oxide layer remains.
- If you do not wish to weld the joint at once, it is advisable to assemble the joint. When this step is done, it is necessary to cover it so that sand and dirt do not penetrate directly into the joint itself.
- Care measures: try to keep the aluminum completely dry. It is recommended to store it at a temperature of +24. It is important that the material be welded in time, otherwise, it is recommended to re-clean the joint.
- Safety is another essential element of welding various materials, particularly aluminum. Special means of providing protection should always be used. These may include such items as a welding helmet, goggles that include different shades of lenses to provide effective eye protection; special protective boots on the feet, and gloves on the hands.
- The latter will help effectively protect against dangerous spatter, and metal sparks. It is also recommended to provide effective ventilation, by which the fumes from welding can be removed from the breathing area. It is recommended to study the safety manual thoroughly.
How Easy is it To Weld Aluminum?
The stick welding process has its place in the practice of aluminum welding. Most of the basic “laws” of stick welding apply to aluminum alloys.
Because stick welding is not the best choice, this method still has its positive qualities: flexibility in the process. There is no need to use a shielding gas. In addition, stick welding is well suited for parts that have rust, or are painted.
You can use a method such as a contact welding aluminum (stick welding), but it can be very unpleasant because there is the contamination of the material. The most effective methods that can be used in this process are TIG-welding, MIG on AC-welding, or DC.
Welding rods: it is recommended to make your stick welding aluminum (aluminum welding rods) approximately 1/8″ as thick as the steel.
Learn more about stick weld aluminum techniques below.
Examples of Aluminum Welding Process
The various types of the welding methods that should be used for aluminum welding are available: GTAW/TIG, GMAW/MIG, GTAW/TIG.
Until now, the Tungsten arc welding (TIG) was the most frequently performed method for welding aluminum for most welders around the world. How to use this welding process: It is often used by automotive enthusiasts and experienced electric arc welders It is also known as shielding gas tungsten welding.
Many car enthusiasts as well as specialist welders prefer to use a method such as tungsten electrode welding (tungsten arc welding – TIG). This work is usually done in 100% argon (it is used as an inert gas), there is no need to use a mechanical wire feeder, otherwise, it can lead to problems.
Therefore, to avoid unfortunate consequences, the welder feeds the aluminum filler metal into the puddle (after the weld pool is formed). This prevents contamination as the aluminum oxide is removed during welding. This also prevents aluminum contamination during the entire welding process.
Recommendations for carrying out TIG welding
- The most appropriate choice for aluminum is the rod. It is important that the latter consist of pure tungsten. A tungsten electrode can also be used.
- Operations such as cleaning as well as preheating are necessary during the preparation of the aluminum.
- It is necessary to check that there is not too much argon flow in the burner. It can cause an irregular arc.
- A heat sink must be used to eliminate the possibility of deformation.
When welding, it is essential to prevent fouling of the stick or filler electrode. Core material along with the electrode (rod) must be melted together. This is necessary to create a welding puddle.
GMAW/MIG
A common method developed specifically for welding aluminum is GMAW. The quality of the weld is directly related to the travel/separation rate. This method is also called otherwise: MIG (“inert gas welding”).
This method of welding has a fairly high deposition rate compared to TIG, but at the same time uses a proper wire feeding system. This suggests that the welder needs to use an appropriate spool gun to feed the wire.
Successful aluminum MIG welding without a spool gun can occur if a graphene gun liner is used. Multiple-pass straight beads must be both externally and internally beautiful and free of defects.
It is important to ensure that the filler rod, as well as the main material, are clean to prevent the risk of porosity of the aluminum, they should not include moisture, but have a special coating of a special protective shielding gas such as pure argon.
Recommendations for MIG aluminum welds
- A special pusher must be prepared directly for wire feeding.
- The edges that are joined to each other require careful machining, as well as effective cleaning of the aluminum alloy and also removal of aluminum oxide.
- During the weld metal, it is recommended not to pull the wire – it is better to push at an angle of ten to fifteen degrees.
- It is recommended to use several successive passes. This is what provides a significant improvement in the appearance of the weld, and also helps to avoid probable damage, which greatly improves directly such an indicator as reliability.
To avoid excessive heat it is recommended to use a heat sink. The latter provides a slower welding speed.
Other Ways to Weld Aluminum
MIG welding as well as TIG methods are the most popular methods for welding aluminum products. But there are also other methods.
Electron-beam welding, as well as laser beam welding:
The first method (electro-beam) is often used in the work of the welder, and has a high precision and area of impact, which makes this method excellent for welding aluminum.
The second method is used to make and easy to make a clean and smooth weld. Also, this method is good to use for those materials that are considered most sensitive to all kinds of cracks, particularly aluminum.
Resistance welding: this type of welding involves joining metals by applying pressure as well as passing a current through the metal to be joined.
This method is well suited to work on products made of aluminum. But here the welder needs to provide that this metal has a fairly high electrical and thermal conductivity.
In some situations (cast aluminum), to weld aluminum, such a method as arc welding in a shielding environment (SMAW or shielded metal arc welding) is used. Examples include: repairing aluminum elements using DC devices with different aluminum electrodes; with positive polarity.
What types of welding are not suitable? Because of the likelihood of porosity, any type of welding for which flux is used is not recommended. These include resistance welding as well as another method, submerged arc welding.
Things to Avoid When Welding Aluminum
Let’s analyze the most frequent mistakes that are important to prevent when welding aluminum parts after considering different methods:
- Lack of proper training: for the type of material being welded, it is the training that is important. This is also not unimportant for the specialist who deals with the welding material. Cleaning aluminum and its quality storage are important before you start welding. It is important to well analyze all the subtleties of aluminum welding, as well as learn the skills. It is not advisable to undertake anything until proper preparation has been provided.
- Using a “one-size-fits-all” approach: The welder must use a completely different approach if aluminum is used than in the case of a material such as steel itself. The welder should not use experience with a different metal or other materials because aluminum is unique. There is a certain degree of danger that can arise in this situation.
- Neglecting the small details: many professional welders say that even the smallest elements need to be paid special attention. In this area, even a small inaccuracy can have complex consequences, especially when it comes to working with aluminum. It is very important to follow every small detail and double-check the results of your work because, in the long run, this will have a favorable effect on clients and further professional careers.
- Lack of suitable PPE: there is some degree of danger when welding aluminum, so it is important to use appropriate PPE. In addition, it is important, to learn safety techniques as well as best practices for welders. This is the key to a long and rewarding career in this field.
- Lack of patience: it takes quite a long time to learn how to weld aluminum. Keep practicing and don’t give up: hard work and perseverance are important, and it will pay off in the end!
Important Property of Aluminum
The thin aluminum oxide layer
Aluminum is characterized by a feature that creates difficulties when welding the metal: A thin layer of aluminum oxide begins to form directly when the aluminum is exposed to the outside air.
It is this oxide aluminum layer that provides a unique silver-gray color. In addition, the thin oxide layer of aluminum also makes the product impervious to external substances, corrosion, moisture, and air. It protects the aluminum, so to speak.
Why remove the thin aluminum oxide layer?
A thin layer of aluminum oxide gradually begins to increase on its aluminum – exterior. It is important to try to get rid of the aluminum oxide if a piece of aluminum is to be welded.
Can a thin aluminum oxide layer be removed first?
It is not a good idea to remove the aluminum oxide first. To begin with, the aluminum piece should be completely cleaned of grease, oil and grease, and dirt so that nothing gets into the piece when removing the aluminum oxide layer.
Temperature specifics of a thin aluminum oxide layer
As stated above, at higher temperatures than aluminum, there is a layer of aluminum oxide that begins to melt. The welder needs to be extremely careful not to burn holes when working, even though this thin aluminum oxide layer only melts at high temperatures.
Benefits of Using Aluminum wire
Some beginners may have a question as to what aluminum should be used for if it causes problems when performing welding work.
More recently, aluminum has become actively used as a material for the production of metal structures. It is known that in the year 84 of the 19th century, the category of precious metals included aluminum itself. It was at this time from it was built the pyramid of the monument was. At that time, aluminum was not used very often.
Two years after the construction of the monument, aluminum was widely used on an industrial scale. This is since, in the 86th year of the 19th century, the process of obtaining pure aluminum from aluminum oxide was discovered. At the time, many experts believed that aluminum had many advantages, and used it to make various types of machinery, such as cars, trucks, airplanes, trailers, railroad cars, kitchenware, and marine equipment.
There are some positive qualities of aluminum despite the presence of negative properties, such as the difficulty of working with the material.
Advantages
- Lightweight: material such as aluminum has an optimal ratio of weight and strength, and it is stronger relative to steel, even at lower temperature values – this makes it a good choice directly for those projects that need high strength.
- Electricity as well as heat: the electrical and thermal conductivity of aluminum is as good as that of the other metal, copper.
- No likelihood of corrosion: Aluminum oxide protects the metal, even though it leads to some difficulties.
- Providing recycling type: aluminum provides economy and is also used for recycling type. This is one of the reasons for its prevalence.
- Exterior condition: sealant, as well as the paint, comes in aluminum, which absorbs them well, for this reason, it is often chosen.
- Because aluminum welding is becoming more common, it’s not unimportant that today’s welders have relevant experience. To gain it, it is necessary to undergo hands-on training, which takes place in an appropriate educational program at a technical university.
You must be trained in the 4 most common welding methods, specifically TIG and MIG welding. Stick welding is also recommended to explore, even though stick welding is usually not the first choice when it comes to welding aluminum. This training program covers techniques for welding in different positions: horizontal, vertical, and flat. They are used when working with metal aluminum sheet.
FAQ
1. Can you weld aluminum without gas?
Shielding tungsten inert gas may not be used when arc welding aluminum in a vacuum chamber because the purpose of the gas is to displace other – atmospheric gases that contaminate the weld. A stable arc does not occur as a result of their influence.
2. What is the hardest metal to weld?
It is difficult to solder iron with lead, aluminum with bismuth, etc. Therefore, to ensure the weldability of dissimilar metals, a third metal is usually used, which has mutual solubility with the metals to be welded. In addition to the properties of the base material metal, weldability depends on the type and method of welding, filler metal and flux composition, and sometimes the shielding gas.
3. What is the weakest metal on earth?
The weakest metal is mercury, which is liquid at room temperature, followed by gallium, which melts in the palm of your hand.
4. What metal can you not weld?
It is practically impossible to solder metals that can not dissolve each other in the molten state: Iron and lead, iron and magnesium, and lead and aluminum. These vapors in the liquid state hardly mix and form layers that are easily separated during subsequent solidification.
