How to cook duralumin with an electrode

What is duralumin, what are its features? Argon welding technology for duralumin

Duralumin is one of the most popular alloys used in industry. It got its name from the company that introduced it into production - Dural.

What is duralumin and what are its features?

Welding duralumin is a technically complex process due to the characteristics of the material itself. Aluminum accounts for 93.5% of this alloy. It also consists of 4.5% copper, 1.5% magnesium and 0.5% manganese.

This alloy derives most of its performance properties from the aluminum component: it is chemically active, forms a strong oxide film, and quickly oxidizes in air.

It is worth noting that the given composition values ​​may actually change, since there are several grades of the alloy depending on its heat treatment and the ratio of metals in the composition.

Due to the melting temperature of the welding process, the electrodes may melt quickly and the parts being joined may leak. Consumables are selected according to the type of duralumin. For materials alloyed with titanium and copper, OZA-1 rods are used, for materials alloyed with iron and titanium - OZA2.

The key parameters of duralumin are the following:

• maximum fluidity – 250 MPa;
• material density – 2.5-2.8 tons/m³;
• The melting point is approximately 650°C (which is identical to the melting point of aluminum).

The main advantage of this industrial alloy is its high strength, which is combined with low weight. This makes it possible to make various reliable metal structures and mechanisms from it, which has led to its widespread use.

When working with electrodes during the welding process, the welder needs to clarify the grade of duralumin, since different additives can be used when alloying it: iron, copper, manganese, silicon.

Welding of duralumin is carried out in accordance with GOST 14806-80.

Advantages and disadvantages

The advantages of duralumin during welding include:

1. If you follow the welding technology, you can get an even and high-quality seam , and the metal can withstand heavy loads while being light in weight.
2. To weld duralumin, you can use several welding technologies : argon welding and semi-automatic welding, which will be chosen by understanding the factors and conditions of the work.
3. It is quite easy to select suitable electrodes for the work . Electrodes such as OZA-1, OZA-2, OK96.20, OZANA-1, OZANA-2 are suitable for welding.
4. No serious labor costs for preparatory procedures.
5. Welding does not require serious specialist classification.

But this process also has certain disadvantages:

1. Welding of duralumin is characterized by low resistance to corrosion , and after welding, its technical characteristics deteriorate.
2. The welding process is quite complex : it requires great care and precision, since even a small error negatively affects the quality of the products.
3. Difficulties may arise with the selection of electrodes due to the impossibility of accurately determining the grade of duralumin.
4. Forming a roller is quite difficult , since the metal is quite fluid.
5. To simplify the work process and reduce welding time, it is necessary to use flux or shielding gas . Flux will be applied to the surface of the part being welded to protect the area from the aggressive influence of the external environment and improve the quality of the connection. The intended purpose of using inert gases in welding will be similar.
6. High-quality welding of duralumin is a fairly expensive procedure ; it allows you to obtain a strong and reliable connection when using expensive consumables, for example, argon.
7. If high-speed welding is used, it is very difficult to control the quality of the seam.

Argon welding technology for duralumin

Various methods can be used for welding duralumin. At home, welding is used using an electric arc apparatus with consumable electrodes or welding with a gas torch. Whereas in production conditions semi-automatic machines and argon welding are used:

• semi-automatic machines , which involve feeding wire in an environment of protective inert gases (DC MIG);
• equipment working with tungsten electrodes in an argon protective inert gas environment (AC TIG).

Let's consider the technology of welding duralumin based on the argon arc welding method. Welding aluminum alloy with argon allows you to work with materials of various thicknesses, creating the most accurate seams with good tightness. This makes this technology very popular in the process of repairing cars, boats and other containers.

Preparation of material

Before starting work, it is necessary to prepare the material for welding, since the presence of an oxide film on the surface reduces the reliability of the welded joint: the film has a high melting point and density, which makes it difficult to form a stable electric arc. To do this you need to go through the following steps:

1. Clean the surface of the workpiece from metal, oils, grease and various contaminants . To remove the top refractory layer, sandpaper and a metal brush are used.
2. After the cleaning is completed, to consolidate the effect, the surface is cleaned with acetone or solvent , which allows you to get rid of residual elements that could interfere with welding. Otherwise, defragmented particles may remain inside the seam, which reduces its rigidity.
3. Process the edges to create a seam . If the thickness of the edges of the workpiece exceeds 4 mm, then the corners must be beveled at 35 degrees.

The rods must be preheated to 150 degrees to remove moisture and dried.

You need to start welding no later than 24 hours after cleaning, and it is better to start it within 3 hours.

An effective way to remove oxide film is also cathode sputtering, in which metals are bombarded with ions, cleaning the surface. The method is mainly used in the industrial field.

Necessary equipment

During the process, the device is adjusted to alternating current (this is the only way to achieve the desired results). Therefore, when making seams, you need to use a welding transformer or other current converter.

Thus, welding of aluminum alloys is allowed only on machines that support operation with direct and alternating currents.

In addition to the fact that welding equipment must be stocked, in the process of selecting it it is worth considering the following characteristics:

1. The equipment must be convenient for transportation in a car.
2. It is desirable to have an oscillator for welding.
3. The burner must have a straight hose with a length of up to 3 meters.

Approximate cost of DC inverter devices on Yandex.market

The success of the welding process largely depends on the correct setup of the equipment. Thus, insufficient gas supply in the welding zone leads to foaming of the metal and burning of the tungsten wire, while excessive blowing, on the contrary, interferes with the formation of the seam and increases the cost of the process.

Welders also need to avoid creating a crater at the end of the weld. It can occur when the arc suddenly breaks. Holding the torch in one position for a long time can lead to overheating and an increase in the area of ​​the weld pool. That is why argon arc welding of aluminum alloys requires competent additional mode settings to attenuate the arc and gradually reduce the current. Taking into account these features, it is necessary to correctly set the voltage parameters.

Polarity can be forward or reverse. In this case, the voltage parameters are set based on the thickness of the material:

Plate thickness, mm	Current strength, A	Electrode diameter, mm
1	from 30 to 40	1,6
1,5	from 45 to 60	2,3
2	from 70 to 80	2,3
3	from 90 to 120	3,2

The current supply during the welding phase can be set:

1. Step type.
2. Ascending value as the seam is carried out.
3. With smooth ignition.
4. With gradual attenuation upon completion of combustion.

Then the argon flow rate is set on the pressure gauge. In Russian models, values ​​are set in the range from 6 to 11 liters, and the optimal flow rate must be selected experimentally. Imported pressure gauges allow you to accurately set the flow rate.

In the settings of the welding machine, the argon purge time is set to 5 seconds. This is a sufficient time period for the bath to solidify and cool the electrode.

When welding aluminum with argon, it is necessary to correctly select the diameter of the tungsten electrode, which must be as close as possible to the thickness of the welded parts. The nozzle projection is set to 3-5 mm to avoid overheating of the tungsten.

Welding process

The argon welding process involves the following steps:

1. The plates are placed in a convenient position.
2. The torch must be brought close to the workpiece so that there remains 3 mm between the surface of the parts being welded and the electrode.
3. The device turns on and the electric arc ignites.
4. When a puddle of molten metal forms, an additive must be supplied to the welding zone.
5. The burner must be directed evenly : from right to left.
6. When the seam is completed, the corresponding button is pressed and the arc extinguishes.
7. The torch continues to be held above the welded zone until the zone is no longer purged with argon.

The welding itself, in addition to the preliminary preparation of the metal, has the following requirements:

1. The metal is heated slowly and gradually so that it does not deform under the influence of high temperatures.
2. The first stitch is worth trying on the training surface.
3. After completing the process, the seam must be gradually heated until the metal being welded cools down.
4. Don't forget to clean the joint and check the seam.
5. When performing work, it is necessary to take into account the high fluidity of aluminum : it is preferable to carry out work in the lower position. The speed of the weld must be extremely high so that a melt pool does not form.
6. Taking into account the fact that aluminum melts quickly, if the diameter of the filler wire is incorrect, you may not have time to feed it into the welding zone and form a seam . The thickness of the solder should correspond to the thickness of the plates. The welder also needs to take into account the chemical composition of the solder (for example, materials for food-grade aluminum are not suitable for duralumin).

Also, the welder should not forget about safety precautions. All work should be carried out in a special protective suit, mask and gloves. Before using this or that device, it is necessary to check all contacts and connections for reliability.

Compliance with all the above requirements allows you to obtain a strong and reliable connection.

Thus, duralumin alloys have become widely used industrially due to their low weight, strength, and corrosion resistance. When welding duralumin, you need to take into account the properties of the metal. Due to its tendency to oxidize, shielding gas or flux must be used during the welding process. When carrying out argon welding with a refractory tungsten electrode, the highest quality connections can be obtained.

Source: https://elsvarkin.ru/texnologiya/svarka-duraluminia/

How and with what to brew duralumin at home

29.03.2019

Dural alloys owe their name to the German company Dural, which began producing parts from various aluminum alloys. Due to its low specific gravity, strength, and corrosion resistance, duralumin is often used by manufacturers. Welding duralumin requires taking into account the characteristics of duralumin. The hot working method is selected depending on the conditions, the skills of the welder, and the responsibility of the connections.

Properties and weldability of duralumin

The physical properties of duralumin are similar to aluminum. The light alloy is difficult to weld; it is chemically active, oxidizes in air, and forms a strong oxide film. Welding of duralumin is often carried out in garages and small workshops. It is necessary to take into account the physical properties of the alloy: high density, the presence of an oxide film, fluidity.

When working with electrodes, the grade of duralumin is specified, because different additives are used for alloying: iron, manganese, copper, silicon. During the production of parts, duralumin is additionally strengthened, the metal loses its ductility. Dural is cooked at temperatures up to 300°C, using flux or a protective atmosphere, since the metal is prone to oxidation.

Welding duralumin at home

Durable aluminum alloys have already entered all spheres of human economic activity. These materials are often used, break down and need repair. In addition, new structures are assembled from them.

Therefore, the topic of welding aluminum at home, with various types of machines that many craftsmen have, is very relevant.

To weld aluminum alloys, you need to keep in mind certain features that are important to take into account in your work, and our task is to consider in detail the technology of this process, the necessary equipment and equipment. We will try to study this topic carefully.

Types of aluminum alloys

Aluminum is not used in its pure form; it is produced in the form of alloys with different physical and chemical properties and is used wherever low weight and good strength properties are important.

These alloys oxidize very quickly in air and form a refractory oxide film on the surface of the workpiece. Therefore, welding aluminum at home requires a special approach to the procedure for joining parts.

The durable oxide layer melts at a temperature of more than 2000°, and the alloys themselves have a melting point of about 600° and their different types have different weldability.

You can understand how to weld aluminum with the best results by familiarizing yourself with the types of alloys that metallurgists create and give them certain qualities. The material differs in strength, weight parameters and ability to withstand repeated loads. Aluminum alloys are composed of several chemical elements, in different combinations, and consist of the following varieties:

• AMts alloy, consisting of manganese impurities and aluminum, welds well;
• aluminum-magnesium alloy AMg3 can be welded without restrictions, and the limitedly weldable varieties are the alloys AMg1, AMg5 and AMg6;
• silumin has an aluminum-silicon composition of grades Al2, Al4 and Al9 with limited weldability;
• grades B95, AB and AK, heat-sealable alloys with difficult weldability;
• duralumin grades D16 and D1, an alloy of aluminum and copper, difficult to weld.

When repairing aluminum products, it can be quite difficult to determine which alloy the part belongs to, but every possible effort must be made to do this. The optimal selection of electrodes, welding wire and output current depends on the weldability parameter.

It is important to understand that the better the grade of material is determined, the higher the quality of the seam and the durability of the connection will ultimately be.

Types of welding for aluminum alloys

The complex chemical composition of the alloys, as well as the oxide, refractory layer, does not make it possible to connect welded workpieces and repaired products in the traditional way. Therefore, the characteristics of welding dictate the use of special electrodes, wires and protective gases that prevent oxidation.

The thickness of the workpiece has a great influence on the quality of the seam, and it should be noted that aluminum has a significant expansion coefficient and high thermal conductivity, which leads to deformation of the seam if the technology is violated.

The most popular methods of welding aluminum alloys are the following types:

• welding using the MMA method with coated consumable electrodes, direct current of reverse polarity, without shielding gas;
• AC TIG method using a tungsten, refractory electrode in an inert environment, alternating high-frequency current;
• MIG welding, using semi-automatic feeding of aluminum wire, with a torch in a protective atmosphere of argon or its mixture with CO2.

The most applicable welding method at home is MMA, but it will be difficult to achieve a thin seam using this method. In addition, the work is preceded by a certain preparatory process of processing the workpieces and calcining the electrodes, and it may be necessary to repeatedly pass through rather expensive electrodes. Not suitable for thin-walled workpieces, and for significant thicknesses it requires edge processing.

The TIG method is more suitable for working with thin-walled workpieces and making a better quality seam. MMA+TIG devices are relatively inexpensive and can significantly expand the range of available work. The so-called argon-arc welding of aluminum is performed using a refractory tungsten electrode and a torch into which an inert gas is supplied.

Semi-automatic MIG welding involves a controlled, automatic supply of wire, which also serves as an electrode, into the weld pool and an inert gas environment. The method makes it possible to achieve very good quality, but requires qualifications and is more expensive than previous methods.

Important. When welding aluminum at home, remember the safety rules, use special clothing and a Chameleon protective mask or its equivalent.

Necessary equipment for welding

For inexpensive MMA welding, you will need a welding machine, preferably an inverter type. It is lighter than a step-down transformer and has an expanded range of adjustments. You will need the following tools and materials, namely:

1. MMA inverter device;
2. special coated electrodes for welding aluminum alloys;
3. grounding cables and with electrode holder;
4. welding mask;
5. file and wire brush;
6. solvent and flux;
7. grinder and hammer for removing edges and removing slag from the finished seam.

Since the workpieces have high thermal conductivity, pads may be needed under the reverse side of the seam, and the removal of edges depends on the thickness of the metal and is done as necessary. During repairs, it will be possible to weld the defect after particularly thorough cleaning of the area where the intended welding will take place.

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Work with argon welding will require more expensive equipment and manual feeding of welding and filler wire. In addition, a protective environment of argon, helium or a mixture of gases is necessary, but the result lives up to expectations.

Using the TIG method you can weld a variety of metals of different thicknesses and for this you will need:

• inverter MMA+TIG welding machine;
• Eurohose for gas supply;
• torch with tungsten electrode holder;
• reducer with pressure gauges for supplying a mixture of gases;
• connecting hoses;
• aluminum welding wire with additives or flux;
• welding helmet and leggings.

The work is carried out by melting the oxide layer with a pulsed high-frequency current and obtaining a weld pool into which the wire is progressively manually fed. A protective gas cloud is supplied to the pool a little earlier than the welding process, which provides protection from an aggressive oxygen environment.

It must be remembered that the refractory tungsten electrode is very sensitive to contamination, which impairs the quality of welding.

For the MIG method, you will need an adjustable, automatic wire feed device and a torch of a different design that ensures the advancement of the melting element to the metal joint.

At home, repair work on aluminum products or joining of small workpieces are most in demand, so aluminum welding technology using MMA and TIG methods will be the most suitable. Workpieces 5-7 mm thick are welded using direct current of reverse polarity, but for parts of greater thickness, technological preparation will be required. Welding aluminum using the MMA method consists of the following operations:

• thorough mechanical cleaning of the workpiece surface from the oxide, refractory layer;
• degreasing the surface using solvents;
• remove the edges of parts with a thickness of more than 5 mm at an angle from 45° to 65° to obtain a more durable, uniform seam;
• before work, you need to calcinate the electrodes on aluminum, since their coating is hygroscopic;
• the parts to be welded are heated to 250°C in order to more effectively melt the oxide layer;
• Aluminum welding is carried out with a current of reverse polarity, the strength of which depends on the thickness of the workpieces, weld parameters and alloy composition.

It is important that the seam should not be too thick, otherwise it will be porous and cracked, so for massive parts, it is better to make several passes.

Working with the TIG method at home is slightly more expensive, but the quality of the seam is incomparably better. The process technology consists of performing the following operations:

• the apparatus must contain an oscillator that improves welding parameters and melting of the refractory oxide layer;
• non-consumable tungsten electrode, set 5-6 mm from the tip to avoid excessive consumption of expensive gas;
• argon is supplied at a flow rate of 5-8 liters per minute, depending on the thickness of the workpieces, then voltage is applied with a delay;
• After receiving the weld pool, the welding wire progressively melts.

Welding of the alloy is carried out with pulsed alternating current and allows you to connect thin-walled workpieces, and if difficulties arise, you should seek advice from specialists.

Conclusion

We talked about the technology of welding aluminum at home using an inverter. This process requires caution and compliance with safety regulations. If financial capabilities allow, it is better to purchase an MMA + TIG machine, which gives more scope for welding a wide variety of metals, including aluminum alloys. The choice is yours.

Sergey Odintsov

Source: https://steelfactoryrus.com/svarka-dyuralyuminiya-v-domashnih-usloviyah/

Welding duralumin: how and with what it is done, features of this metal, working technique

Duralumin is considered the most successful aluminum alloy. Its composition: aluminum (93.5%), copper (4.5%), magnesium (1.5%), manganese (0.5%). The alloy got its name from the name of the company that first began its production - “Dural”. The material immediately became widespread due to its qualities.

The lightness and strength of duralumin, its wear resistance and ability to withstand heavy loads have made its use very widespread. Duralumin is widely used in aircraft construction, the production of military equipment, high-speed trains, pipes, sheets, profiles for construction work, etc.

Due to such a wide use of the alloy, the welder has to work with it quite often. Although working with this alloy is somewhat easier than working with pure aluminum, without sufficient experience and skills it is difficult to achieve good results, and a beginner may not be able to cope with such a task.

Features of duralumin

Duralumin parts, like aluminum ones, are difficult to weld at home. They do not connect well, which is due to the technical characteristics of the alloy. Main parameters of duralumin:

• Fluidity – 250 MPa
• Melting point – 650o C
• Density – 2.5 – 2.8 t/m3

The high melting point causes the electrodes to melt quickly, which can lead to metal flowing out of the welding zone. To improve the quality of welding work with duralumin, it is recommended to use auxiliary means such as flux or shielding gas. Argon is most often used for this.

If the technology is not followed, cracks may form in the material and the weld seam will be uneven. The alloy's resistance to corrosion is minimal; rust can form on the seam itself during the welding process. This is due to the fact that the metal, when exposed to high temperatures, is very sensitive to the effects of oxygen.

Requirements for welding work with duralumin at home are contained in GOST 14806-80.

Positive aspects of duralumin

If all instructions are followed, we will receive a high-quality, even weld, and the product, despite its low weight, will be able to withstand serious loads. There are several options for welding duralumin; you can choose the optimal one, depending on our capabilities and requirements for welding results.

The most common methods are the use of a semi-automatic machine and the use of argon in welding processes. Another advantage is the large selection of suitable materials for welding; in particular, a large number of electrodes interact well with this alloy.

This primarily applies to the following brands: OZA-1, OZA-2, OZANA-1, OZANA-2, OK 96.20.

Negative points

Duralumin is not resistant to corrosion; after welding, this feature becomes even more pronounced. The welding process itself requires high precision and attention; the slightest mistake can significantly affect the result. Due to the high fluidity of the alloy, it is difficult to form a high-quality seam. When working with duralumin, it is mandatory to use protective materials.

This may be flux - a special substance applied to the area being welded to protect it from environmental influences. Inert gases, such as argon, also perform this function well. Protection of the welding zone significantly increases the speed and quality of welding.

However, these methods significantly increase the cost of implementation, which is also a disadvantage. Welding duralumin requires a lot of experience and skills; if you don’t have them, you shouldn’t experiment.

Preparation for welding

Before carrying out welding work, we need to set the parameters of the welding machine, as well as prepare the material and welding components for welding. First of all, it is necessary to clean the surface of the parts being welded from dirt, grease, oxide film, etc.

For this purpose, physical and chemical cleaning methods are used. In the first case, a metal brush, sandpaper, and a grinding machine are used. To consolidate the effect, you can then use the chemical method - continue cleaning with acetone or solvent.

The next step is preparing the edges to be welded. If their thickness exceeds 4 mm, it is necessary to grind off the edges at an angle of 35°. Then, flux should be evenly applied to the site of the future seam, this will help improve the quality of the seam. It is recommended to warm up the parts to be welded before starting welding.

This must be done evenly and slowly to avoid deformation of the metal. It is also recommended to heat the welding electrodes in a muffle furnace. Welding must be done quickly, since duralumin melts very quickly.

At the end of the welding process, it is necessary to avoid sudden cooling of the parts, gradually heating the seam. At the end we must clean the resulting joint and check the seam for cracks.

Strict adherence to safety precautions is important, as with any other type of welding work. Welding must be done in a protective suit, gloves, and a welding mask. All welding equipment must be checked before starting the process, special attention must be paid to contacts and connections, they are mainly the source of malfunctions.

Aluminum electrode welding

The special properties of aluminum cause difficulties when joining parts made from this metal. To date, several methods have been developed with which you can cope with such a task as welding aluminum without much difficulty.

Aluminum electrode welding

In industrial conditions, argon arc welding is used for such purposes, but at home, in the absence of the necessary equipment, welding aluminum with an electrode using an inverter or DC transformer may be suitable. Carrying out welding work to connect aluminum requires special preparation and compliance with certain work rules.

Features of working with aluminum

An electric arc allows you to connect various types of metals, including aluminum, by significantly heating the parts. It allows you to melt metal plates of various thicknesses, which helps create a strong connection. But joining aluminum parts is associated with certain operational difficulties.

Welding seam on an aluminum part

Aluminum has some characteristics that are unusual for most metals, one of which is its hygroscopic property. This property of metal lies in its ability to absorb moisture from the environment. Many people are unaware of this because cold aluminum has no visible evidence of moisture accumulation.

But with significant heating, moisture begins to evaporate at the welding site. This leads to excessive splashes, operational difficulties and poor-quality connections.

To prevent the occurrence of defects, aluminum products should be preheated to a temperature of 150 degrees. This can be done using a gas burner. In this case, moisture will evaporate from the aluminum surface and will not interfere with high-quality welding work.

Do-it-yourself aluminum welding also involves the problem of coating the metal with an oxide layer. The oxide film occurs during a chemical reaction between aluminum and oxygen molecules. It protects products from exposure to acidic environments, while at the same time preventing welding work.

This is due to the large difference in the melting temperature of pure metal and its oxide. The melting point of aluminum is 500 degrees, and its oxide – 2000 degrees. Therefore, before welding aluminum products, it is recommended to clean the metal surface with a wire brush.

This allows access to pure metal.

However, the cleaned surface is very quickly exposed to oxygen, resulting in the formation of a new oxide layer on the surface. Therefore, in industrial conditions, welding of parts is carried out simultaneously with the supply of inert gas - argon. It prevents oxygen from accessing the metal and the formation of a new oxide film.

At home, you should also create a gas cloud when welding using an inverter.

You should also take into account the fact that aluminum in its pure form is practically not used. Most often, alloys based on it are used, which have improved properties. Some additional components may interfere with the creation of a high-quality seam.

Welding aluminum with an electrode at home must be carried out strictly in accordance with the characteristics of the aluminum alloy and the requirements for the type of electrode.

Electrodes for welding aluminum products differ significantly from other types, since they are coated with a special coating of a chemical mixture of salts, usually fluoride and chloride. This coating allows you to create a gas cloud without the use of pure argon.

Electrodes for aluminum

There is a certain classification of electrodes depending on the purpose and type of aluminum alloy, the parts from which need to be connected.

The most widely used aluminum electrodes and their purposes:

1. OZA-1 is an electrode designed for connecting elements made of pure aluminum, without additional components. Before welding, the surface must be cleaned to remove oxide film and preheated to remove moisture.
2. OZA-2 – used to correct casting defects and surfacing of aluminum-silicon alloys.
3. OZANA-1 - necessary when using the technology of welding pure aluminum, the thickness of sheets of which exceeds 1 cm. This requires preheating to a temperature of no more than 400 degrees.
4. OZANA-2 - used in the same cases as the OZA-2 electrode, but can also be used to connect parts and aluminum alloys, such as silumin and duralumin.
5. OK96.20 - this type of electrode is intended for welding aluminum alloys using manganese, magnesium and silicon. Can be used for working with duralumin.

The quality of the weld directly depends on the correct choice of electrode, so it is very important to determine the type of alloy. Typically, manufacturers mark products with information about the properties and characteristics of the metal.

Welding aluminum with an inverter

Welding aluminum at home with an inverter is carried out in strict adherence to step-by-step instructions.

Welding aluminum with an inverter

The whole process can be divided into several stages:

1. Inverter pre-setting:

• you should set the AC mode using the AC/DC toggle switch, switching it to AC mode;
• polarity balance adjustment is carried out depending on the type of metal from which the product is made; for pure aluminum you need to use the negative part of the range, and for alloys – the positive part;
• The welding current is adjusted in accordance with the thickness of the metal product and the diameter of the welding electrode (for a three-millimeter electrode and a two-millimeter sheet, a current of 60 A is recommended);
• the slowdown in the decay process of the electric arc is set at 3 seconds, and is adjusted depending on the characteristics of the metal;
• you should set the time for purging with inert gas, which is required to cool the seam.

1. Stages of preparing metal parts for welding aluminum with an inverter:

• cleaning the surface with a metal brush or sandpaper, which is necessary to get rid of the oxide film, you need to achieve a white shine effect;
• surface treatment with chemicals, which is required to degrease parts and obtain a high-quality seam;
• heating the parts to a temperature of 400 degrees, which should be carried out immediately before welding.

1. After carefully completing all the necessary preliminary work, you can begin the actual welding. Connecting operations should be carried out at a moderate pace. This is very important for uniform heating of the workpieces and creating a high-quality seam.
2. The electrode should be fed directly to the beginning of the weld pool, preferably maintaining an angle of 15 degrees. In order for the finished seam to be uniform and of high quality, the touch of the electrode should be soft and light. In this case, the seam should be slightly ribbed.

Before performing complex welding work on aluminum products, you should obtain the necessary skills. To do this, you can practice on old unnecessary parts, watch training videos and consult with experienced specialists. Experts, based on their own experience, can point out some features of the work that cannot be found in the specialized literature, and can also point out mistakes made during training.

Source: https://stankiexpert.ru/spravochnik/svarka/svarka-aljuminija-elektrodom.html

Welding duralumin at home - Metalworker's Guide

The process of welding aluminum is very labor-intensive. This is due to the characteristics of the non-ferrous metal. Special modes are being developed to reliably fasten aluminum products and its mixtures. Let's look at the question of how to cook aluminum.

Area of ​​use

Aluminum is a non-magnetic material, so its mixtures have unusual characteristics: light weight of parts, high conductivity of energy of any type, resistance to mechanical stress.

Aluminum alloys are used in welding devices for various purposes, as they have a lot of useful qualities: low density, increased resistance to corrosion processes and high specific strength.

Non-ferrous metal in its pure form is very fragile, so it is used only in certain sectors of industry. It is known to be widely used as semiconductors.

Features of welding aluminum parts

Welding aluminum is difficult due to its characteristics. Main features of aluminum welding:

• There is always an oxide shell on the surface layer of the metal. The melting point of the oxide is 2037 degrees, and the colored element itself is three times less, about 660 degrees Celsius.
• The metal is easily oxidized, so to weld it you need to protect the work area from harmful exposure to air.
• Spreads abundantly in the work area. Therefore, there is a need to use pads that remove heat from the area being welded.
• The seam is not always strong, as cracks and pores may appear in it. The formation of pores in the metal is facilitated by the gas that is dissolved in it, and it tends to escape into the atmosphere. The appearance of cracks is inherent in aluminum alloys, due to the high silicon content when the metal is cooled.
• Tendency to significant shrinkage.
• Due to the excessive thermal conductivity of the metal element, it becomes necessary to use an increased welding current.

The main features of aluminum welding are given, but there are many more. Therefore, metal is considered a capricious element and brewing it is a problematic matter.

Welding methods for aluminum parts

To carry out the process, different methods of aluminum welding are provided, for example, the use of various compositions and devices, special elements for enclosing the welding area.

By special means, as a rule, we mean fluxes and inactive gases. Flux is a powdery substance, diluted with water to obtain a state resembling sour cream, and spread onto the twists with a brush or by dipping.

The powder is able to rid the metal of the oxide layer and prevent sticking of the carbon electrode.

The most popular options for welding aluminum at home and in production conditions are:

• welding of aluminum with an electrode using a sphere of inactive gases (AC TIG method);
• semi-automatic welding of metal in the field of inert gaseous substances with automatic supply of filler rod (DC MIG - aluminum welding technology);
• the use of fusible electrodes surrounded by a flux shell without gas and the use of gaseous substances (MMA option)

The main condition for cooking a colored element and its mixtures is the need to remove the film layer from its metal surface. To destroy the layer, you need alternating or direct current, but of reverse polarity. As a result, cathode sputtering is carried out, and the oxide shell is destroyed.

The process of welding aluminum parts at home

Situations arise when there is an urgent need to join difficult-to-weld metals at home and therefore a logical question arises, how to weld aluminum at home or simply how to weld in general? A person often has to deal with them, since many household supplies are made of aluminum or its mixtures.

But one problem arises: it is difficult to create the necessary conditions so that welding with aluminum electrodes is similar to that at a production facility. Therefore, the quality of the connection may suffer. Usually, primitive welding of metal is carried out at home, that is, welding aluminum at home with an inverter.

The device is used for argon arc cooking.

Welding aluminum at home is characterized by a number of useful indicators:

• Cost savings, especially if appropriate equipment is available;
• Instant results. The quality of the seam is determined immediately;
• The use of improvised elements.

Defects in welding parts in the home environment. Among the shortcomings of the work are:

• low quality seam;
• difficulty in selecting available materials;
• difficulties in maintaining personal safety when working with gaseous substances;
• there are no necessary conditions for storing electrodes for aluminum welding.

Preparing metal surfaces for welding

Preparing aluminum for welding involves a number of operations:

• Chemical treatment. It is necessary to clean the working metal surfaces from contamination, in the form of grease and oil deposits. Technical solvents, such as acetone or white spirit, are used to degrease parts. In addition to solvents, etching in alkaline baths is widely used. The alkali rate is 50 g/l, exposure time is 60-90 seconds. After alkaline treatment, the parts are washed with water. This is followed by a clarification operation; for this, the workpiece is kept in a solution of nitric acid for up to 2 minutes. This is followed by washing again and blowing with hot air.
• Mechanical cleaning of workpiece surfaces (edges). For this operation, you will need a grinding machine with a steel wire brush attachment or a regular file. After such cleaning, the surface is degreased with a technical solvent.

Manual electric arc welding with specially coated electrodes (MMA technology)

Electric arc welding of aluminum is used to create conventional (non-critical) structures with a metal thickness of at least 4 mm. This welding method has a number of disadvantages: low-quality weld, excessive spattering of metal during operation, low slag separation, which may result in a rusting process.

Electrodes with special coatings are used to weld both pure non-ferrous metal and its mixtures, for example, duralumin. Currently, electrodes of the UANA and OZANA brands are produced, replacing the outdated OZA models.

The connection of lightweight metal surfaces is carried out using direct current with reverse polarity. A current of 25 amperes is received per 1 mm of electrode.

To create a high-quality metal seam, it is heated to 350-400 degrees Celsius. Thus, welding of duralumin is carried out with preheating of the part to 300 degrees Celsius. This heating and subsequent cooling operation are done in order to get rid of the possibility of crystallization cracks appearing, as well as to reduce the deformation of the material. For welding volumetric products, it is advisable to use local heating of the working area.

Upon completion of the work, you should get rid of unnecessary residue from the seam. To do this, the metal surface should be washed with hot water and treated with a metal brush.

Welding with a non-consumable electrode in argon (AC TIG method)

Electrode welding is the most popular procedure as it is used to create structural shapes. Consumable items are subject to special requirements in terms of strength components.

The electrodes for welding aluminum are special here - tungsten rods of 1.6 - 5 mm are used, which can withstand temperatures of 3 thousand degrees Celsius, and filler wire with a diameter of 1.6 - 4 mm. These tungsten rods are almost never consumed, since they only take part in generating the electric arc.

The filler element is an aluminum rod. Shielding gases are helium or argon with a high level of purity.

The arc is powered from an alternating current source capable of efficiently removing the oxide shell. The main parameters, namely the diameter of the electrode and rod, the numerical value of the welding current - all depend on the equipment used.

The parameters of the welding area should be at a minimum level. The speed of the electrode welding process on aluminum depends on the flow rate of inactive gas.

If gas is used in excessive quantities, it leads to undesirable consequences, namely air entering the work area.

It is worth noting that the gas (argon) is supplied 4 seconds before the arc ignites, and is turned off 7 seconds after its destruction.

Semi-automatic aluminum welding (DC MIG technology)

Pulse equipment is considered the most effective way to weld lightweight metal, as it is more productive. The resulting high voltage surge quickly destroys the oxide shell, then it instantly tends to the base value. Each particle of the molten metal rod (electrode) is driven into the welding zone. Thanks to this “filling”, a high-quality seam is created. This is how spot welding of aluminum is obtained.

Such equipment is not cheap. Some craftsmen have learned to modify standard semi-automatic machines for welding aluminum surfaces, and now they can easily work with aluminum with minor modifications.

According to the principle of operation, the technology of welding with a semi-automatic device does not differ from the standard mode of steel welding. But there are some technical aspects:

• It is unacceptable to cook aluminum and mixtures with current with direct polarity, only the opposite option.
• Aluminum rod is softer than steel rod, which can create loops. To eliminate this, you need to get a special feeder with 4 rollers, a small sleeve and a Teflon liner.
• When heated, non-ferrous metal expands more than steel, so a situation may arise where the wire gets stuck in the tip of the feeder. To avoid such incidents, you need to use special tips marked Al or standard models, but with an increased diameter.
• By comparing the welding wire made of aluminum and steel, the non-ferrous metal rod melts more intensely. Therefore, an accelerated feed rate should be ensured. Otherwise, frequent tip replacement is necessary.

  Welding equipment made in Russia

Special materials, tools and practical recommendations

The process of joining parts requires certain skills and depends on the selected welding method. Among the tools necessary for optimal operation of aluminum welding at home are:

• Welding equipment. The device becomes the main power source, which provides the required current supply.
• Electrodes or filler wire. The selected elements must correspond to the selected welding method.
• Gas cylinder with connecting hoses.
• Grounding for electrical equipment;
• Technical means of protection.

When welding aluminum, you should be guided by certain conditions:

• wire and electrode - at an angle of 90 degrees;
• the additive is supplied by reciprocating manipulations;
• Transverse vibrations of the tungsten electrode are unacceptable;
• maintaining an arc length from 1.5 to 2.5 mm;
• welding of thin aluminum is carried out with a lining of steel or copper to remove heat and avoid burn-through;
• The welding process occurs from right to left.

Safety precautions

Welding aluminum at home is quite unsafe. At home, the risk of traumatic situations occurring is at a high level. Gas and electrical safety instructions must be followed.

Welding aluminum parts involves protecting the worker himself. It is necessary to use full welder equipment (robe, mask) and some other auxiliary personal protective equipment.

Before you start connecting aluminum with your own hands, you should familiarize yourself with the video, which explains the basic rules for working with the holder and equipment.

Welding aluminum is not an easy task. This process requires some skill. If you follow all the rules and recommendations for welding finicky metals, you can achieve the desired result.

Source: https://ssk2121.com/svarka-dyuralyuminiya-v-domashnih-usloviyah/

Electrodes for welding duralumin

Modern industrial production is developing by leaps and bounds, and over time, many different ways of connecting metal parts have appeared. However, they are all conditionally divided into two categories:

1. Detachable (that is, they can be dismantled without violating the integrity of the entire structure).
2. One-piece (during dismantling the structure is destroyed).

The last category also includes connections using welding seams. It is often used with steel parts, but in some cases there is a need to weld aluminum products.

What does a beginner need to know?

Welding aluminum is characterized by one significant feature: upon contact with oxygen, a kind of oxide film appears on its surface, which can only be removed by chemical action. This explains the use of substances designed to prevent its formation and allow direct contact with the metal surface. All such products are called fluxes.

In addition to fluxes, during the welding process at home it is necessary to use a tool used to remove dirt. We are talking about special steel brushes.

Basic welding methods

Welding aluminum at home can be carried out using two different methods.

1. The area of ​​the future joint is heated with a gas burner.
2. Using electrical voltage, where the stability of the spark is controlled by a closed electrical circuit.

Gas welding of aluminum

Step one.

First, you should take care of all the necessary tools. In addition to all of the above, gas welding also uses a small-sized aluminum rod , which allows not only to obtain a high-quality seam, but also a reliable connection.

I would like to devote a few words to these rods.

Firstly , there are several modifications of it, which are chosen depending on the percentage of aluminum in the metal and its thickness. Thus, the rods can be about 3% manganese or more, with a diameter of 2 to 4 millimeters.

Secondly , such rods are sold by weight: if necessary, you can purchase one or five kilograms in a compact plastic cartridge.

Don’t forget about the gas burner itself—you won’t be able to cook anything without it.

Step two.

After we have carefully prepared for work, we can begin to clean the surface of the part at the places of future joints. This is where a steel brush comes in handy.

Step three.

After cleaning, the contact areas (and the surface closest to them) should be treated with flux. This will prevent the appearance of an oxide film and give us access directly to the aluminum itself.

We heat the gas burner to the required temperature and use it to heat the seams. At the same time, we apply an additional rod, which, under the influence of fire, melts and mixes with the main mixture, connecting them at the same time.

Electric welding

This kind of aluminum welding at home will require you to have extraordinary skills and craftsmanship.

After all, here it is necessary not only to optimally choose the diameter of the electrode used (remember, it is this that closes the contact at the joint and heats the metal to a temperature as close as possible to the melting point), but also the necessary mode of operation of the welding device. Read more about how to properly cook with electric welding

Electric welding is often with metal whose thickness does not exceed four millimeters. In addition, it has a number of disadvantages:

1. The quality of the seam leaves much to be desired.
2. During operation, metal splashes.
3. Poorly separated slag, which can subsequently cause rust.

Step one.

Preparing for work. We collect all the necessary tools (which were described earlier), prepare the welding machine and select electrodes. It is desirable that these are electrodes coated with aluminum - they melt several times faster than steel ones, hence the higher operating speed.

Step two.

We activate the welding machine. It should be noted that for aluminum of medium thickness a temperature from 250°C to 300°C , and for thick, massive parts - about 400°C.

Step three.

When welding, it is recommended to cool it slowly after heating the aluminum. This will prevent the occurrence of crystallization cracks, and also allows you to obtain a sufficient degree of penetration with minimal energy consumption. If we weld large parts, we use local heating.

We weld the necessary parts. Under no circumstances should the electrode vibrate transversely!

Step five.

After the welding is completed, we remove the formed slag from the seam, wash the seam and re-treat it with a steel brush. Otherwise, the structure will rust.

Some recommendations

Source: https://rem-serv.com/elektrody-dlya-svarki-dyuralyuminiya/

Welding duralumin at home: technology and features of the work

Aluminum, due to its high quality characteristics, is one of the most popular metals. Its main area of ​​application is industry. Aluminum alloys, namely duralumin, are also used.

This compound received its name in honor of the Dural company, which first established the production of the alloy. According to experts, welding duralumin is considered a rather labor-intensive process. You will be required to be as focused and attentive as possible.

You will learn how to weld duralumin at home from this article.

Getting to know the connection

Before you start welding duralumin, you should know about the main parameters of this alloy. Duralumin with a maximum fluidity of 250 MPa has a density ranging from 2.5 to 2.8 t/cubic. m. Melts at a temperature of 650 degrees. This indicator is inherent directly in aluminum itself. This explains why duralumin begins to flow during welding due to the rapidly melting electrodes.

What is the difficulty of the procedure?

Judging by numerous reviews, complications cannot be ruled out when welding duralumin. The reason for this is the technical characteristics of the alloy, which contains aluminum (93.5%), manganese (0.5%), magnesium (1.5%) and copper (4.5%).

According to experts, their connection to each other is poor. Therefore, it is better for welding work with duralumin to be carried out by an experienced person.

If you have a need to connect parts from this alloy, you will have to take into account some nuances, which will be discussed in more detail below.

About the methods

The connection can be made using semi-automatic devices. The machine for welding duralumin operates in pulse mode. Thus, the metal heats up under the influence of pulses, and after a drop enters the weld pool, a seam is formed. If you decide to go with this method, you should know that constant negative polarity on the electrodes will not create a seam. All you need is a positive one.

The second method is to use tungsten-coated electrodes. This method will provide a high-quality and neat seam. To prevent the formation of an oxide film, argon is used.

Also, the formation of a gas protective environment is carried out using xenon, krypton and nitrogen. However, these gases, unlike argon, will cost you more. In order to weld products with a thickness exceeding 30 mm with tungsten electrodes in one pass, you need to use a three-phase arc. Conventional connections are mainly used to connect surfaces with a thickness of no more than 3 mm.

If you do not have the opportunity to perform electric arc welding, use cold welding for duralumin. First, you should acquire a special composition, namely two-component glue. It can be a thick liquid or mastic.

It contains epoxy resin and steel powder, which makes the formed connection stronger. Additionally, to improve the characteristics of cold welding, namely increasing adhesion between parts and resistance to aggressive environments, manufacturers fill the adhesives with special additives.

This method is also called soldering by many. The fact is that parts can be connected without electricity. All you need is a portable gas burner and NTS-2000 solder in the form of a wire. It’s easy to seal cracks or connect duralumin parts.

You need to heat the part so that the solder and the rod begin to melt and begin to flow into the gap.

The oxide film is first removed from the surfaces. Unlike previous methods, cold welding is much faster. Mainly using these adhesive compositions, various emergency situations are quickly eliminated when parts made of aluminum or its alloys need to be connected quickly. Judging by the reviews, most home craftsmen prefer this method.

About the advantages

Despite the fact that the welding technology is quite complex, if you do everything correctly, you will end up with an even and high-quality seam. The advantage of this alloy is that with a fairly small mass it can withstand a large load. Judging by numerous reviews, argon welding of duralumin is considered quite popular.

The connection can also be made using a semi-automatic device. The choice of the most optimal option depends on the master. According to experienced welders, when dealing with this alloy, there are never any problems with the choice of electrodes. The fact is that many of them can interact well with duralumin. For example, you can use brands such as OK96.

20, OZA-1, OZANA-1, OZA-2 and OZANA-2.

About the disadvantages

According to experts, duralumin has low corrosion resistance. This figure becomes even lower after welding. When welding, you will have to be very careful, since the slightest inaccuracy will negatively affect the quality of the connection.

Due to the high fluidity of the alloy, forming a seam will not be easy. To simplify this procedure and speed up the process, experienced welders use flux. It must be applied to the surface of the parts to be joined. As a result, the quality of the connection will be higher.

In addition, the seam will be protected from aggressive influence from the outside.

Where to begin?

Welding work begins with the preparation of workpieces. Various contaminants are thoroughly cleaned from the metal surface and degreased. You can work with sandpaper of various grains or a wire brush.

Fats are effectively removed using acetone or solvent. After cleaning and degreasing, you should work on the edges, where the seam will be located in the future. If it turns out that your workpieces have edges of more than 4 mm, then they need to be beveled a little.

An angle of no more than 35 degrees is considered optimal.

Second step

At this stage, flux is applied. It is important that it covers the welding area evenly. To prevent the metal from deforming, it is first subjected to slow and gradual heating. At the end of the procedure, the suture itself is heated. The connection you make will be covered in slag. It needs to be knocked down carefully. This recommendation should not be neglected, since there are very often cracks under the slag. As a result, the connection will have very low load resistance.

What else do experts recommend?

Experienced craftsmen recommend using an additive for welding duralumin. This product is presented in the form of a durable and rigid lamellar rod. Judging by the reviews, with the additive the metal will be used more economically, and the strength characteristics of the structure will be higher. When working with this alloy, as with any other metal, you should adhere to safety precautions. Before you start welding, purchase a special protective suit, mask and gloves.

Source: https://labuda.blog/263180

How to weld duralumin

Aluminum is a metal that has high quality characteristics and is actively used in industry. The most common aluminum alloy is duralumin, which got its name thanks to the Dural company, which was the first to produce such a compound.

Welding duralumin is a rather labor-intensive process that requires concentration and care. The complexity of welding work is due to the performance characteristics of aluminum, because in the duralumin alloy, the amount of aluminum is 93.5%.

The alloy also contains copper - 4.5%, magnesium - 1.5%, manganese - 0.5%.

This alloy is quite often used in industry, and therefore welders constantly have to work with this composition. Welding duralumin should be carried out by a person with experience, since the technology is not simple and one has to deal with a number of nuances during the welding process. Therefore, a beginner is unlikely to be able to weld duralumin on his own.

Note! Duralumin weighs little, but is a very strong and reliable alloy.

articles

• Features of duralumin
• Advantages
• ​Disadvantages
• Preparatory work before the welding process

Features of duralumin

Welding duralumin at home, like welding aluminum, is accompanied by difficulties, since these alloys do not join well. This is due to the technical characteristics of the metal.

The main parameters are as follows:

• Maximum fluidity – 250 MPa,
• Density – 2.5 – 2.8 tons/m³,
• The melting point is approximately 650°C (identical to the melting point of aluminum), therefore during the welding process the electrodes melt quickly and the alloy can flow.

Welding duralumin involves the use of special means (for example, flux or argon) to improve the quality of the connection. If you do not follow all the rules for performing the welding process technology, cracks may appear and the seam may turn out uneven.

The metal is not resistant to corrosion, therefore, during the welding process, traces of rust can already be observed on the seam itself, since under the influence of high temperatures, the alloying parts burn out and thus the alloy is practically not protected from the effects of oxygen.

Note! Welding duralumin at home should be carried out in accordance with the requirements of GOST 14806-80.

Advantages

• If you strictly follow all the work technology, then in the end the seam will be smooth and of high quality, and the metal will be able to withstand heavy loads, while weighing very little.
• There are several methods for welding duralumin (argon welding, semi-automatic welding), you can choose the most optimal option, taking into account all the factors and conditions of the work.
• Finding electrodes is not difficult, since many interact well with such an alloy. For example: OZA-1, OK96.20, OZA-2, OZANA-1, OZANA-2,
• Any problem that arises during the welding process can be solved, but it is better to entrust the work to an experienced specialist.

​Disadvantages

• As already noted, duralumin is characterized by low corrosion resistance, and after welding its technical characteristics become even lower.
• The process is complex, requiring care and precision, because... Any, even the slightest mistake can significantly affect the quality of the connection.
• Forming a weld bead is not easy because the metal is very fluid.
• In order to make the work process easier and so that welding takes less time, you need to use flux. It is applied to the surface of the part to be welded.

On a note! Flux is a substance that protects the area being welded from aggressive environmental influences and improves the quality of the connection.

• In order to obtain the most durable and reliable connection, you will have to resort to expensive types of welding, for example, welding duralumin with argon.

Preparatory work before the welding process

Before you start work, you need to prepare the blanks. The first thing to do is to clean the metal surface from grease, oils and various contaminants. For cleaning, you can use sandpaper or a wire brush. After you have completed mechanical cleaning, to consolidate the effect, clean the surface with a solvent or acetone. This way you will get rid of all the leftovers.

At the next stage, you need to process all the edges on which the seam will be created. If the thickness of the edges of the workpiece exceeds 4 mm, it is necessary to bevel the edges at an angle of 35 degrees.

Requirements for welding:

• Metal preparation,
• Flux should be applied to the intended location for the seam and the area should be evenly covered; this substance helps improve weldability,
• The metal must be heated slowly and gradually so that it does not deform under the influence of high temperature,
• After the process is completed, it is necessary to gradually heat the seam until the metal has completely cooled,
• At the final stage, it is necessary to clean the resulting joint and check the seam and slag for possible cracks.

Note! Welding with electrodes requires a high speed of work, because... Duralumin melts very quickly.

Don't forget about safety precautions. When working with duralumin, as with any other metal, you must strictly follow all the rules and protect yourself. Therefore, welding must be carried out in a special protective suit, a mask and gloves. Before using this or that equipment, before starting work, be sure to check whether it is in working order and whether all contacts and connections are reliable, because Usually difficulties and shortcomings happen to them.

If you follow the welding technology and do not neglect the rules and requirements for this process, then you can ultimately get a strong and reliable connection.

Source: http://home.nov.ru/kak-svarit-dyuralyuminij/