How to weld with electrodes on aluminum - Metals and their processing

Welding aluminum with electrodes using an inverter: how to weld correctly

As a rule, special equipment and special technologies are most often used for welding aluminum structures and parts. Welding using manual arc welding is quite difficult . But sometimes it is necessary, and we will help you figure out how to weld aluminum structures with electrodes.

When working with aluminum, the following types of welding are mainly applicable:

MMA (manual arc welding of aluminum (see electrodes for aluminum));
MIG (semi-automatic aluminum welding);
TIG (welding of aluminum in an argon atmosphere using filler wire).

We will not touch upon the topic of agro-arc welding or the use of tungsten electrodes. Below we will talk about carrying out welding work with simple manual coated arc welding electrodes .

Aluminum electrode welding (MMA)

MMA (Manual Metal Arc) - manual arc welding with coated electrodes. This method is far from the most effective when working with aluminum products. Disadvantages of manual arc welding:

it is difficult to make an even seam;
the seam may be porous and not very durable;
when the electrode melts, strong spattering is observed;
It is difficult to clean the seam from slag.

And yet, despite the listed disadvantages, there are situations when manual arc welding cannot be done without . MMA welding can be used to connect aluminum structures that do not bear heavy loads . The minimum metal thickness must be no less than the thickness of the electrode (4 mm).

Manual arc welding with coated electrodes is useful at home when it is not possible to use bulky and expensive equipment .

Welding with inverter

Why, if there are no options other than MMA, is it then recommended to weld aluminum with an inverter? Although welding aluminum with electrodes is a rather complicated process, there is a way to make your life a little easier. Aluminum is a poorly weldable metal, so to achieve an even and high-quality weld, you should use an inverter.

Of course, there are other techniques that can be used in manual arc welding: rectifiers, transformers or generators. However, an inverter is the most profitable option due to the following advantages:

High efficiency - up to 95% and above. The high-frequency pulse semiconductor converter completely eliminates inductive losses.
Efficient energy consumption . The inverter automatically turns off when operation stops.
Protection from unstable electrical network . The inverter produces the required voltage regardless of network sags. The pulse converter automatically adjusts to the input voltage and provides the required output parameters.
Precise adjustment of welding current . The current required for specific welding jobs directly depends on the thickness of the electrodes used. The inverter control knob allows you to set the desired value before starting work.
Quick arc ignition . It is quite easy to hit the part with an electrode. The inverter ensures stable combustion of the welding arc.
Convenient to use at home . Inverters, as a rule, have compact dimensions. For comparison, a welding transformer with a power of 8 kW weighs more than 40 kg, while an inverter of the same power weighs less than 5 kg.

Features of the technology

Let's look at the features of aluminum electrode welding technology. Manual arc welding of aluminum is not the most convenient process, so it is important to know and take into account some features of welding.

Selection of electrodes . First of all, you need to select the appropriate type of electrodes. The fact is that some brands have a coating intended only for working with aluminum alloys. Others are used exclusively for welding pure aluminum. Therefore, this parameter should be taken into account. Electrode manufacturers indicate the purpose of a specific brand, so you can easily choose the right one.
Surface cleanliness . When welding with electrodes, preparation of the surface of the structure is of great importance. It should be well processed so that the seam is smooth and durable.
Current _ Aluminum welding is carried out using direct current of reverse polarity. This is due to the fact that an oxide film forms on the surface of this metal. And with reverse polarity, the film is destroyed using cathode sputtering.

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Chemical properties of aluminum

Aluminum is characterized by high solubility of hydrogen in liquid form with low solubility at the crystallization point. This directly affects the quality of welding work. If even a small amount of hydrogen dissolves in the weld metal, the weld may become porous , as the hydrogen will tend to escape.

Another important chemical property of aluminum is oxidation . The combination with oxygen creates aluminum oxide, which forms a kind of film on the surface of the metal. On the one hand, the oxide film reliably protects the metal from corrosion. On the other hand, it becomes an obstacle to welding work . While aluminum already melts at 660.3°C, the melting point of the oxide film is 2037°C.

Mechanical properties of aluminum

The strength, elasticity and elongation of the weld depend on the type of alloy from which the parts are made, as well as on the composition of the electrode. The strength of the welded joint will be quite weak in cold-hardened alloys. To achieve good weld strength in heat-resistant alloys, longer heat treatment times and slow cooling are required.

IMPORTANT! Aluminum has good thermal conductivity, so it is recommended to use heat-dissipating pads when carrying out welding work. This will help preserve the remaining parts of the workpieces from shrinkage and deformation.

Use of alloying components

To improve the quality of the weld, the following alloying additives can be used in aluminum electrodes:

Manganese (Mn) - increases corrosion resistance.
Silicon (Si) - reduces the melting of aluminum, improves fluidity and weldability.
Magnesium (Mg) - gives the metal excellent weldability and good strength. When combined with silicon, it forms a heat-resistant alloy.

Electrodes OK AlMn1 (96.20) containing manganese

Which electrodes are better

A few words about which electrodes are best for welding with aluminum electrodes. For manual arc welding of aluminum structures, consumables from the manufacturer SpetsElectrod of the Ozana-2 brand are often used. Among the advantages of electrodes of this brand:

ensure stable arc burning;
the seam is well formed in any position (including vertical);
slag formations on the working surface are easily separated;
the weld seam has good mechanical properties.

Electrodes from the Swedish manufacturer ESAB of the “OK” series are also widely used. Consumables with alkali-salt coating are optimally suited for welding structures made of technical aluminum, as well as aluminum alloys with manganese or magnesium.

You can read more about choosing electrodes for aluminum welding here.
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Difficulties of the process

Let's look at the complexities of the electrode welding process on aluminum. The difficulty of manual welding of aluminum structures is largely due to the properties of this metal. Below are examples of the main problems that may arise during the welding process.

High metal fluidity . Molten aluminum is difficult to control. With significant overheating, the behavior of the metal becomes somewhat unpredictable. The melt can destroy the layer of solid metal underneath and flow out through the crack. To solve this problem, it is recommended to use ceramic or refractory steel gaskets .
Oxidability of aluminum . The main problem of aluminum products. Combining with oxygen, metal molecules form a dense oxide film. It is stronger than the metal itself and melts only at very high temperatures. Another disadvantage is that the film is a dielectric, so it is difficult to ignite an arc. To solve this problem, you need to thoroughly clean the metal working surface before welding .
High coefficient of linear expansion . Aluminum is quite fragile and has low elasticity. When the metal is very hot, the welding zone puts pressure on the rest of the structure, which can cause cracks or deformation of flat surfaces. To avoid this, you need to control the welding temperature . It’s better to preheat the part to 200-250°C.
When the weld metal hardens, it can crystallize and hot cracks appear . Therefore, it is advisable to add a special filler material. This is especially necessary in cases where several seams are located at a short distance from each other.

Source: https://WeldElec.com/info/kak-pravilno-varit/alyuminiy/elektrodami/

How to weld aluminum using electric welding

10.04.2019

Aluminum structures and parts sometimes need to be urgently repaired. Having welding skills, many weld aluminum themselves using electric welding. It is impossible to make a quality seam at home. But welding aluminum with an electrode is often used as an emergency measure. When working with light metal, you need to take into account the characteristics of the alloys. Manganese increases oxidizing capacity, magnesium improves weldability, silicon reduces the melting point.

Features of aluminum electrode welding

It is impossible to weld aluminum with an electrode without a protective atmosphere. The hot metal is quickly saturated with hydrogen, the seam becomes porous, the melt splashes heavily, and the seam turns out uneven. To reduce spattering, the metal is welded using a current of reverse polarity, the negative terminal is connected to the part, and the positive terminal is connected to the holder. The workpieces are preheated to +150 – +190°C to eliminate water accumulating in the pores of the oxide layer.

Difficulties arise due to the oxide film; it melts at +2037°C, aluminum - at +660°C. Before welding, the oxide layer is cleaned to a shine. Surface cleanliness affects the quality of the connection.

The alloys have good thermal conductivity, it heats up quickly, cools down, shrinks greatly, internal stresses and cracks arise. When welding metal, heat-dissipating pads are used. They maintain the required temperature.

Light metal is cooked at home at high currents. Electrodes are chosen special ones intended for welding.

Selecting a welding machine and electrodes

Aluminum is a difficult-to-weld metal. The operating current should be 1.5 times higher than for steel. The welding machine must generate a direct current of up to 250–300 amperes. A household welding machine powered by a 220 V network is suitable for the job. You can choose rectifiers, transformers or generators, but it is better to opt for an inverter, its advantages:

high efficiency, up to 95%;
low inductive losses;
reduction of current consumption due to automatic shutdown;
the device calmly tolerates voltage drops in the network;
a stable arc is maintained, it is enough to touch the workpiece;
there are additional functions;
Small dimensions, you can carry it anywhere.

Light alloys with several electrodes coated with salt, forming a slag protective layer:

Ozana, Ozana-2 produced by Spetselektrod;
OK 96.20, 96.10, 96.50, Swedish company ESAB;
UANA of domestic producers.

You can use other consumables designed for welding aluminum castings and alloys. 2mm blanks are cooked with a diameter of 2.5, for 3–4 mm parts a thickness of 3.2 is chosen; maximum diameter of rods – 4

Aluminum electrode welding technology

At home, the workpieces are pre-cleaned. For parts over 3 mm, edges are cut at an angle of 45–60°. The larger the angle, the better the quality of the seam. If the plates are thicker than 7 mm, they are laid with a gap of 2 mm. The cracks are pre-aligned, deepened with a grinder, and the edges are drilled to relieve internal stress.

How to weld aluminum with electrodes:

first, the workpieces are grabbed in several places;
the root seam is carried out, holding the electrode perpendicularly;
thick parts are boiled in several passes, each layer is tapped to remove scale;
The surfacing bead should protrude by 2-5 mm depending on the thickness of the parts.

Aluminum must be welded in compliance with the operating mode (workpiece thickness, mm/current, A):

Workpiece thickness, mm	Current, A
2	50 – 70
3 — 4	80 — 110
5	90 — 130

Beginner welders need to practice on non-working surfaces before making a weld to get used to holding a short arc.

Electric welding is used to repair parts operating under static compression load. This is not the most effective repair method. The seams cannot withstand twisting or bending and immediately crack.

How to weld aluminum using electric welding Link to main publication

Source: https://svarkaprosto.ru/tehnologii/svarka-alyuminiya-elektrodom

How to weld aluminum: description of electrode welding technology - Machine

page » About welding » How to weld correctly » Welding aluminum » Welding aluminum with electrodes

When working with aluminum, the following types of welding are mainly applicable:

MMA (manual arc welding of aluminum (see electrodes for aluminum));
MIG (semi-automatic aluminum welding);
TIG (welding of aluminum in an argon atmosphere using filler wire).

We will not touch upon the topic of agro-arc welding or the use of tungsten electrodes. Below we will talk about carrying out welding work with simple manual coated arc welding electrodes .

Do-it-yourself aluminum electrodes: how to make, characteristics, features, rules of application

Welding elements made of low-melting metals can be compared in labor intensity to refractory metals. The first and second ones are influenced not only by internal, but also by external factors.

Electrodes for aluminum include various additive materials, which simplifies working with this non-ferrous metal and creates additional protection.

But they are not able to relieve the welder of all the preliminary aspects that must be resolved before starting the welding operation.

Aluminum rods are widely used not only in industrial enterprises, but also in everyday life - a garage, a country house, a small repair shop.

However, using them at home to connect parts with an inverter, you may encounter certain difficulties. And only correctly selected surfacing material and preliminary preparation will help to qualitatively connect the structure.

Technical features of electrodes

The thickness of the parts to be connected is limited by the diameter of the rod, which generally ranges from 4 to 5 mm. Operations with thinner electrodes are fraught with difficulties due to the increased melting rate of the rod.

The latter melts three times faster than steel. Based on this, it is recommended to weld aluminum parts with a thickness of at least 4 mm. The produced length of 3 mm rods is 22-30 cm, 4-5 - 35-45 cm.

The main difficulties that arise during the aluminum welding process are the following factors:

oxide film - formed on the surface of the joined elements, and the first melting temperature is more than three times higher than the melt of aluminum itself - 2,000 ° C;
rapid oxidation of the metal leads to the formation of a refractory film, which complicates the production of a solid seam;
to prevent metal spreading, heat-conducting pads should be used;
the presence of silicon in aluminum alloys promotes the formation of crystallization cracks;
if the operation is accidentally stopped, a layer of slag appears at the end of the electrode and the weld pool, making it difficult to re-ignite the arc;
Due to the high linear expansion rate, the welding bead is deformed during its hardening.

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Welding operations with aluminum will require an increase in current strength by 1.5 times compared to other metals.

Performing welding

To ensure a high-quality connection of parts, it is necessary to pre-clean their surfaces from all kinds of contaminants and oxides and prepare the joints. At home, this will be facilitated by various solvents, in production - by alkaline baths.

Among the first to be used are white spirit, technical acetone, xylene and white spirit-based solvents - PC-1, PC-2. The alkaline bath allows the part to remain in the composition for no more than 5 minutes.

You can prepare an alkaline bath yourself, for this you will need:

water - 1 l;
soda ash - 50 g;
technical trisubstituted sodium phosphate - 50 g;
silicate glue - 30 g.

To improve cleaning, the alkaline liquid must be heated to a temperature of 65°. After removing the aluminum workpiece from the bath, you need to clean the ends intended for joining with a metal brush specially designed for this purpose, with fine bristles or a file.

Manual labor can be completely replaced by a grinding machine. After cleaning, the elements should be cleaned again with solvent.

Conductive rods for the welding operation will also require preparation before welding. To obtain a high-quality roller, the electrodes must be kept in an oven for two hours at a temperature of at least 200° C.

The welding operation involves the use of direct current of reverse polarity, with a value of up to 30 A for each millimeter of welding rod diameter. It will improve the quality of the connection by preheating the parts to 300-400°.

The amount of heating is directly proportional to the thickness of the structures being connected. However, if large-sized parts are to be processed, only the ends intended for welding are heated.

The following operations will help ensure a high-quality roller:

the seam is freed from the formed slag crust;
the roller is watered with hot water;
cleaned with a wire brush.

Slow cooling of the weld bead will help prevent warping and crystallization defects during welding.

Source: https://prosvarku.info/elektrody/elektrody-dlya-svarki-alyuminiya

How to weld aluminum with an inverter - Technique Expert

In everyday life, products made of aluminum alloys are used, which occasionally require repair.

Is it possible to weld aluminum at home with an inverter? Yes, with the help of special electrodes, home craftsmen weld cracked or new products.

How to cook aluminum with an inverter without argon

First, special aluminum electrodes for electric arc welding are purchased. In this article, you can get acquainted with melting rods for joining aluminum alloys.

Aluminum welding with an inverter is performed using direct current of reverse polarity (+ on the electrode holder). For a running electrode with a diameter of 3.2 mm, the welding current on the machine is set to 80-100 A.

When connecting aluminum alloys, the holder with the electrode is placed at a right angle (90 degrees). The technology is performed with a short arc.

Please note: aluminum electrodes burn 3 times faster than usual, maintain the correct speed.

Thick metal more than 5 mm needs cutting edges. The V-shaped chamfer is cut with a bevel of 45-60 degrees.

Before welding, the workpieces are heated with a gas burner to 150-200 degrees for drying. And the electrodes are pierced in an oven according to the manufacturer’s instructions.

Without heating the aluminum products and drying the melting rods, the connection will not work.

As the workpiece heats up, you will see water appear on the surface and evaporate.

Further, the products are installed with a technological gap between them of 1-2.5 mm, depending on the thickness of the plates.

The oxide film is removed with a stainless steel brush (the use of abrasive tools is not recommended; abrasive particles will create joint defects).

After preparations, aluminum is welded with an inverter. After each pass, with thick metal, slag is removed with a hammer. Slag welding is not performed. Electrodes for aluminum alloys require cleaning of the tip as the process continues.

Aluminum alloys are divided into difficult and easy to weld. The table will help determine the weldability characteristics.

Welding inverter for aluminum welding

Inverter welding machines for aluminum welding are purchased in different brands and modifications. We looked at the use of electric arc devices. In practice, semi-automatic devices and attachments are also used for connections in a protective gas environment.

This article explains how to learn how to weld aluminum using argon gas.

Connecting wires by welding

How to weld aluminum wires with an inverter? The essence of the technology is simple:

remove the insulation from the wires;
make a twist;
trim the twist (wires at the same level, length more than 30 mm);
apply flux to remove the oxide film.

For connection, graphite or carbon electrodes and flux are purchased. Flux is a white powder, diluted with water until creamy and applied to the twists with a brush or by immersion. The flux removes the oxide film and prevents the carbon electrode from sticking.

The connection is made without an arc, by simply bringing the electrode to the twist for 1-2 seconds. On the inverter device, the current strength is set to 20 A.

The tip of the electrode must sometimes be cleaned of slag and scale. Before important work, it is better to practice on blanks.

After work, wipe the aluminum connections with solvent, apply varnish and insulate.

Source: https://kumselstroy.ru/drugie/kak-varit-alyuminij-invertorom.html

Welding aluminum with an electrode at home

The peculiarities of aluminum welding cause certain difficulties when joining this metal. The developed technologies, to one degree or another, make it possible to combat this and achieve positive results. The quality of aluminum welding using an inverter cannot be compared with argon arc welding or other Al joining technologies.

However, in domestic conditions it is unlikely that suitable equipment will be found.
The master may have at most a home welding machine at his disposal, be it an inverter or a DC transformer. Reasonable questions arise: is it possible to weld aluminum with an inverter at home, how to do it correctly and what materials are required for this?

What a welder needs to know

According to experienced welders, electric welding of this “winged” metal without argon can be no worse than argon.
Those craftsmen who talk about the mediocre quality of the weld and poor weldability using this method either did not weld aluminum with an electrode at all, or approached this method incorrectly. Please note the following recommendations:

The butt connection is the most acceptable. People try to avoid T-type and overlap types of welded joints due to the high probability of slag flowing into the gaps, which causes corrosion.
After welding, the seam is washed with water to remove slag;
Preparing aluminum before welding is mandatory. Removal of oxide film, protection from its re-formation;
Welding of massive parts with a thickness of more than 3 mm is accompanied by cutting the edges at an angle of 60° with a V-shape.
Preheating of Al before welding to 150-250 °C.

Do not forget that technically pure aluminum is welded better than its alloys containing magnesium and manganese (duralumin, silumin).

That is why you should choose the right welding electrodes depending on the chemical composition of the alloy.

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Electrodes for aluminum

The most common brands of electrodes for welding aluminum alloys: OZA-1, OZA-2, OZANA-1, OZANA-2, OK96.20. Electrode rods are made from welding wire and coated with a mixture of chloride and fluoride salts. The coating thickness is no more than 0.30.5 mm per side.

Electrodes for aluminum OZANA-2

Let's consider a more detailed purpose of each electrode.

OZA-1 - for parts and structures made of technically pure aluminum A0, A1, A2, A3. Welding with preheating along cleaned edges.
OZA-2 – for welding casting defects and surfacing aluminum-silicon alloys AL-4, AL-9, AL-11.
OZANA-1 - welds technically pure aluminum with a thickness of products more than 10 mm. Preheating at a temperature of 250-400 C.
OZANA-2 – for AL-4, AL-9, AL-11 alloys, surfacing and welding of casting defects. Can be used as a connecting material for products made of duralumin and silumin.
OK96.20 – aluminum-manganese alloys AMts; aluminum-magnesium alloys AMg2; AMg3; AMg5; AMg6; aluminum-silicon alloys AL-4; AL-9; AL-11. Suitable for duralumin

Aluminum electrodes are more expensive than conventional electrodes and are very hygroscopic, i.e. they absorb moisture from the surrounding air.

Aluminum welding technique with coated electrodes

Aluminum welding with an inverter is carried out with direct current of reverse polarity, preferably in the lower position. The point is not even the high fluidity of aluminum, but the welding speed, which increases 2-3 times compared to steel.

The electrode melts very quickly and you simply cannot make a seam in a vertical position, much less in a ceiling position.

Important! Electrodes should be calcined before welding.

The electrode should be held predominantly in a vertical position or slightly tilted. Move the end of the electrode in the direction of the seam. Welding is performed in one pass on a short arc, without lateral movements.

The chemical elements of the coating create increased electrical resistance of the welding seam, and therefore create obstacles when re-igniting the arc. They try not to make the seams long.

In case of arc breakage, the slag crust from the crater and the end of the electrode should be removed and overlap the previous one by at least 1 cm to avoid the formation of pores when filling the crater.

Upon completion of welding, the weld seam must be cleaned and washed with water to avoid corrosion.

Welding modes with aluminum electrodes

Conclusion

The toxic smoke released during welding, as well as the high cost of electrodes and their capriciousness in storage, will not make this method more popular than MIG or TIG. It is used, as a rule, in cases where it is impossible or inappropriate to use gas equipment.

Source: https://svarkagid.ru/tehnologii/kak-varit-alyuminij-invertorom.html

Electrodes for aluminum, welding at home with an inverter

The unique properties of aluminum as a metal result in serious difficulties in welding work with it. These difficulties are understandable, and methods for solving them are known. In order to choose the most optimal working technology in a particular “aluminum” case, it is necessary to understand the properties of this extremely interesting and capricious metal.

There is no escape from working on it: no metal can compare with it in popularity, the automotive industry alone is worth it. Aluminum is widely used in aviation, space and many other industries.

At the same time, this metal is extremely capricious in welding work; it is one of the most complex materials, requiring a differentiated approach to each technological case. Aluminum electrodes are a key element for obtaining high quality welds.

Why is aluminum difficult to weld?

Welding aluminum using a TIG inverter.

It's all about physics and, in particular, melting point. Aluminum itself melts at very low temperatures, not exceeding 650°C.

Unlike other metals, it does not change color when heated, making it very difficult to tell when parts are ready to form a weld.

All this would not be so scary if the oxide film, which forms on the surface of this metal at lightning speed, did not interfere with the process.

Film behaves completely differently. Firstly, in order to melt it, the temperature must be raised to 1750°C. Secondly, the oxide is much heavier than the metal itself, so during welding it is immersed in it and thus solidifies. A simple and elegant solution to problems with oxide film is to thoroughly clean the surfaces of aluminum workpieces - this is one of the mandatory requirements in aluminum welding.

Aluminum gets along well with other metals and forms alloys for a wide variety of purposes, sometimes with diametrically opposed properties. These alloys are also not without problems. There is a high risk of cracks when working with them. This occurs due to the metal's insufficient tensile strength when it is in a partially liquid and solid state at the boundary temperature range. As a result of shrinkage stress, parts are deformed during the cooling process in the form of cracks.

Types of electrodes for aluminum

OZA is made from aluminum wire and is used for pure aluminum and aluminum alloys with silicon.

Features of aluminum welding using argon arc welding.

OZA – 1 are suitable for almost any aluminum alloys and surfacing. These are consumable electrodes on aluminum made of a metal rod and coated with salt. The diameter can be very different. In operation, you need to use direct current of reverse polarity. Used for workpieces with edge thicknesses ranging from 3 to 16 mm. Preheating of parts to a temperature of 250 – 400°C is mandatory. The consumption of OZA-1 is quite high: two kilograms of electrodes are consumed per kilogram of metal blanks. The composition of the weld is complex: more than half nickel, copper, manganese, iron. After completion, be sure to rinse the seam with heated water, then clean it with a wire brush. The disadvantage of these consumables is the difficulty of welding in a vertical position, which can create an unnecessary side arc. As a result, you can only work in the lower position.
OZA – 2 – highly specialized consumables for aluminum alloys with silicon. Salt coating. The consumption is the same: two kilograms per kilogram of metal.

Alkaline salt OK.

This type includes brands 96.10, 96.20 and 96.50.

Consumables 10 of Swedish production ESAB are used in the argon-arc method and are the most preferred option in this technology. Their feature is a coating of a new composition from a mixture of chlorine and fluorine salts. As a result, the arc is smooth and stable without metal spattering. The seam is of high quality and aesthetically pleasing. In operation, preheating of workpieces is preferable, but not required. Unlike OZA-1, heating does not affect the quality of the seam; it only helps to reduce the consumption of expensive electrodes. Another positive difference from OZA-1 is the ability to carry out welding work on vertical surfaces. The consumption of electrodes is significantly lower due to the characteristics of the coating and thin wire as a rod, which reduces the overall cost of this technology. The weld seam is characterized by high hardness.
OK 96.50 is very popular in mechanical engineering for automotive engine parts, installation of a wide variety of building structures and correction of casting defects in aluminum alloys. The composition is an aluminum electrode: the rod is made of aluminum, silicon and iron with four thickness options. The current is applied constant with reverse polarity. Coating with an alkali-salt composition allows you to form a protective crater to neutralize the oxide film. Preheating of workpieces is very desirable; the optimal temperature is 250 – 300°C.

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Brands of electrodes and areas of application.

Two grades of the OZANA type: OZANA - 1 for surfacing or welding of four grades of aluminum A0 - A3 and OZANA - 2 for welding aluminum alloys AL4, AL9, AL11. Perhaps the most popular consumables of all: they make it possible to form an even arc and a high-quality seam. You can also work in a vertical position, unlike other types of aluminum welding.

OZANA – 1 are designed specifically for working with parts and surfacing of pure aluminum. The coating is made of a salt composition, the rod is made of an alloy of aluminum, silicon and iron. Coating allows you to cope with the oxide film and stabilize the melting process. The current used is constant, reverse polarity. Consumption is slightly lower compared to other consumables: 1.7 kg per kilogram of surfacing. The seam is of very high quality with pronounced anti-corrosion resistance. Preheating of workpieces depends on the thickness of the edges. If it is more than 10 mm, heating to 200°C is recommended. If the edge is thinner than 2 mm, it is necessary to make a preliminary beading of the edges along the intended seam. These consumables must be heated before use for 30 minutes at a temperature of 150°C.
OZANA – 2 is an updated version of OZANA – 1.

UANA - special consumables for working with alloys that are easily deformed.

EHF - tungsten tips for welding in argon.

A special property of aluminum electrodes is their extremely high hygroscopicity; they manage to extract all the moisture possible from the air. Hence, you need to remember about the special conditions for their storage - in moisture-proof packaging and only in strictly dry rooms.

We cook with an inverter without argon

Welding aluminum at home with an inverter is quite possible, and here again the right electrodes will help us - special consumables for aluminum. Of course, the quality of seams using argon arc welding is disproportionately higher than with methods without argon, but for home work, equipment for working in argon is too expensive. Amateur craftsmen most often have only a basic welding machine at their disposal.

Tungsten electrodes for aluminum welding.

Home welding of aluminum with an electrode requires knowledge and implementation of the following recommendations:

Seam connections should only be made butt. Other types such as tee or lap welds are not suitable for aluminum due to the risk of slag flowing into the gaps. This subsequently leads to corrosion.
Cleaning the seam after melting is as important as cleaning surfaces before work. The best way is to rinse the seam with water.
It has already been written here about removing the oxide film before welding, but repetition would not be superfluous: this action is too important.
Finishing the edges of metal workpieces is also extremely important. It all depends on the thickness of the edges. If they are thicker, for example, 3 mm, the groove should be formed at an angle of 60° in a V-shape.
It also doesn’t hurt to preheat the workpieces before welding. In this way, you can at least slightly “even out” the imbalance of low melting point and high heat conductivity.

The rules for choosing consumables are the same and depend on the chemical composition of the alloy - welding aluminum with an inverter in this matter is no exception. Let us immediately note that pure aluminum is welded much easier and better than its alloys. An important factor is the considerable price of aluminum electrodes.

Welding torch device.

The rods of the most popular ones are made of wire coated with a mixture of chlorine or fluorine salts in a very thin layer. A number of brands of electrodes are designed this way, each of them having its own precise purpose with the most detailed details of use.

Electrodes for welding aluminum with an inverter are as follows:

OZA-1 for welding with mandatory heating before the process for workpieces made of pure aluminum with cleaned edges.
OZA-2 for surfacing aluminum alloys with silicon and sealing defects obtained during casting.
OZANA-1 for welding pure aluminum with an edge thickness of more than 10 mm with preheating up to 400°C.
ShchL96.20 for aluminum alloys with manganese, magnesium, silicon, duralumin.

An inverter for aluminum welding can be of various modifications. Semi-automatic machines are more often used, but electric arc machines are also quite suitable.

Homemade consumables for aluminum

Since purchased aluminum electrodes are not cheap, home craftsmen have come up with ways to make consumables.

Brands of electrodes for welding aluminum structures.

Homemade electrodes for aluminum welding are produced using simple technology:

Cut into even pieces 30 cm long from aluminum wire with a diameter of no more than 4 mm.
Prepare a coating or coating from crushed chalk, which must be mixed with silicate glue and mixed thoroughly. Dip the aluminum rods into the mixture.
The coating layer should be approximately 1.5 - 2.0 mm. Dry until the layer is completely hard.

Once again about cleaning

Cleaning requirements are set out in the instructions for each type of aluminum electrodes as a mandatory component of the technology. Oils, greases and small metal particles should be removed with the utmost care. To minimize the risk of scale and high porosity, the edges must be perfectly smooth and clean.

Source: https://tutsvarka.ru/vidy/elektrody-po-alyuminiyu

How to weld aluminum: description of electrode welding technology

Currently, aluminum is used in a wide variety of fields. This thin and flexible material is often found in vehicle parts, including engine blocks, transmissions and body parts. It is also used to create stainless steel containers for household and industrial needs and many other important everyday items.

If a crack or problematic hole forms in such a structure, it is better to close it using a special apparatus in an argon environment. However, not every average person has such a unit at their disposal, so they have to look for more affordable solutions. One of them is aluminum electrode welding .

To successfully carry out such an activity, it is necessary to acquire a certain set of skills and purchase the appropriate equipment and supplies. The principle and technology of such welding are quite simple, so with the right approach you can learn them in a short time.

Features of working with aluminum

Electric arcs are used to connect many types of iron. This technique ensures a sufficiently high combustion temperature, resulting in high-quality penetration of plates of different thicknesses, creating reliable and hermetically sealed protection. However, welding aluminum using an inverter is considered the most difficult due to certain specific characteristics.

The first difficulty lies in the hygroscopic properties of the material, which can accumulate ambient moisture. And although this cannot be noticed in a naturally cooled state, problems will certainly arise when welding begins. When the arc is ignited and the metal is heated to elevated temperatures, moisture particles begin to evaporate from the surface and inevitably penetrate into the welding zone. The result is excessive spatter and interference that prevents a normal seam.

To prevent this phenomenon, it is enough to preheat the structure at a temperature of 150−190 degrees Celsius. In this case, you can notice intense release of moisture on the surface .

The next difficulty is the presence of an oxide film that covers all products. Its purpose is to protect the structure from the aggressive effects of an acidic environment. However, this makes processing with an inverter significantly more difficult.

The main problem is associated with the large difference in melting temperatures. It is known that aluminum itself begins to melt at 500 degrees Celsius, and its oxide at 2000 degrees.

To eliminate such a difference, it is enough to clean the welding site with an iron brush to ensure the required access to the metal .

Interaction with the environment ensures the correct formation of pores in the joint structure, which significantly worsens the tightness. To protect the weld pool, argon or a gas cloud is used during inverter welding.

It is no secret that pure aluminum is practically not used for the manufacture of parts, so the fillers and additional elements included in its composition can become a problem. For example, grades Al2 and Al2 contain silumin from 4 to 13%, so they are usually called limitedly weldable. Similar indicators are typical for models AM r 1 and Amr 6, where manganese is added in a proportion of 2−6%.

Stages of welding activities

Understanding the key intricacies of aluminum welding is not as difficult as it might seem at first glance. Through numerous attempts and experiments, you can achieve successful results and learn such a skill by heart. So, step-by-step actions for high-quality joining of metal products consist of the following stages and features:

If the thickness of the plate being welded exceeds 5 millimeters, it is necessary to cut the edges. To do this, it is recommended to cut the edges at an angle of 45 degrees, although other values are also allowed. It is no secret that the width of the weld seam depends on the size of the cutting angle. If the thickness of the plates exceeds 7 millimeters, then you will have to make a technical gap between each part of two millimeters. If the work object is represented by a crack, then it is widened using a cutting disc and a grinder. Otherwise, the seam will be superficial.
The prepared workpiece is thoroughly heated. A propane-oxygen flame is used to remove excess liquid. The role of the working tool is performed by a cutter or an ordinary can with a household torch. It is necessary to warm the surface to 150 degrees and make sure that the material is dry enough.
After thoroughly warming up, it is necessary to clean the oxide film. In this case, you can use a regular brush to clean the metal. It is important to remove the refractory layer at the beginning of the welding zone. The following actions are carried out using an electrode, the composition and temperature of which can corrode the oxide and re-weld.
Tacks are installed on the prepared product, which secure all parts to be welded. The root seam should be smooth and completely fill the gap. The angle relative to the parts being welded must be at least 90 degrees. This may seem unusual to inexperienced welders, or those who have had to work with carbon steels. However, in this way the molten metal will more accurately fall into the joint. After the surface cools, the slag falls off. Unfortunately, this action is carried out with great difficulty, so you cannot do without a sharp hammer.
The next layers of the seam are applied until the entire thickness is filled.

Preparatory actions

Regardless of the welding conditions - industrial or home, you need to properly prepare the edges of the workpiece . Such an action consists of the following processes:

The surface of the part that will be welded (as well as the surface of the filler material) is thoroughly cleaned of dirt, oil and grease. To degrease the surface, white spirit, acetone, aviation gasoline and many other solvents are used.
The preparatory stage also includes such actions as cutting the edges of welded parts, which is performed only when absolutely necessary. If you do not use coated electrodes when welding, then edge cutting is carried out when the thickness of the parts being joined exceeds 4 millimeters. If the thickness of the aluminum alloy exceeds 20 mm, then the use of electrodes is indispensable. If aluminum sheets up to 1.5 millimeters thick can be welded, then their ends are pre-flanged before joining.
As mentioned above, immediately before welding, the surface of the part must be completely cleaned of the oxide film. In this case, it is common practice to use a high-quality file or a bristle brush to clean the metal. In some cases, a thin layer of oxide film is also removed using special chemicals, such as caustic soda, gasoline and others. When treating with caustic soda, the workpiece must be thoroughly rinsed with running water .

Equipment and electrodes

Pay attention to the list of the most necessary tools and accessories . In most cases, the operation is carried out using a conventional inverter. This device has a convenient design, so it is easy to move or move around the workshop. The polarity is set in such a way that the “plus” is placed in the worker’s hands, and the “minus” affects the workpiece. In this case, you need to get a 220 V outlet.

When choosing electrodes, you should give preference to specialized models such as UTP 48 or similar analogues. They can have different diameters and be selected taking into account the thickness of the metal. The composition of consumable raw materials also has some hygroscopic properties, so it must be pre-dried to ensure a better connection .

According to experienced specialists, electric welding of such flexible metal without the use of argon is sometimes carried out as well as with argon welding. If someone dissuades you from such a decision, arguing that it is of poor quality of the final seam and poor weldability, do not believe it. Most likely, he approached the method incorrectly or never tried to weld aluminum using an electrode .

To avoid irreparable mistakes and unpredictable troubles, it is enough to follow a number of recommendations and rules:

The butt joint method is considered the most promising. Other types in the form of a T-weld or lap welded joint are impractical, since they increase the likelihood of slag flowing into the gaps, which will cause a corrosion reaction.
After welding operations, the seam is washed with water to clean the workpiece from slag.
Immediately before processing, the material must be properly prepared. To do this, remove the oxide film and prevent its appearance in the future.
When welding massive parts with a thickness of three millimeters or more, it is necessary to separate the edges at an angle of 60 degrees with a V-shape.
Primary heating of aluminum is carried out at 150−250 degrees Celsius.

Do not forget that technically pure aluminum can be welded much better than alloys containing magnesium or manganese . We are talking about duralumin or silumin. However, products made from pure material are practically not used, so some difficulties may arise during welding.

Reasons for deterioration of metal weldability

If you encounter any difficulties or unpleasant moments during the welding process, you need to take into account many unique properties of the metal :

The key difficulty of heat welding is the presence of an oxide film, which can only be melted under the influence of temperatures of 20440 degrees Celsius. Melting of the metal itself begins at a lower temperature - from 660 degrees.
Drops of the molten part appearing in the welded zone are very quickly covered with a refractory oxide film, which prevents the formation of a continuous seam. To protect the workpiece from this phenomenon, the welded area is protected from contact with ambient air using argon.
Molten aluminum is characterized by high fluidity, and this significantly complicates the further formation of the weld pool. For this reason, work is carried out using additional heat-dissipating pads.
Aluminum contains dissolved hydrogen, which is directed outward after the molten metal solidifies. As a result, this causes the appearance of pores and crystallization cracks in the seam. In addition, alloys of this metal are characterized by an increased concentration of silicon, which also causes cracks to appear as the product cools.
Aluminum has a decent linear expansion coefficient. Because of this, significant shrinkage of the metal may occur during solidification, which causes a number of serious deformations of the parts being connected.
Welding of pure aluminum and its alloys is carried out under the influence of high values of welding current. Metal is characterized by high thermal conductivity. Also, when welding, it has become common to use currents with lower strength.
Welding parts made of this metal is considered difficult in cases where it is not possible to determine the exact grade of the alloy. In this case, you have to spend a long time and diligently choosing the appropriate welding mode and methods used.

THIS IS INTERESTING: What metals stick to a magnet

Anyone can learn all the intricacies of welding aluminum with an electrode. All you need to do is be patient and willing to set aside a few hours of your time to study the relevant material and guidance. In this case, you will be able to perform many important operations at home, without seeking help from qualified employees .

Source: https://tokar.guru/svarka/tehnologiya-svarki-alyuminiya-elektrodom.html

DIY electrodes for welding aluminum

Aluminum electrodes for welding are metal rods coated with coating. The coating protects the metal from oxidation and improves the quality of the weld. They are practically not used in large workshops and factories, since their efficiency is not enough to perform large volumes of work. But such electrodes are widely used by home craftsmen.

A carbon electrode is often used to weld aluminum. In this article we will tell you everything you need to know about aluminum rods and explain in detail how to make your own welding electrodes.

Features of welding aluminum at home

Anyone who has welded aluminum at least once in their life knows that this is a very difficult task. There is an oxide film on the surface of the metal, which makes the welding process difficult. Do-it-yourself aluminum welding electrodes can solve this problem.

But before you start, you need to thoroughly clean the surface. Remove contaminants and carry out comprehensive preparation of the metal for welding. This will improve the quality of the seams and they will last longer.

For high-quality welding of aluminum parts, you need a welding machine that produces direct current and is connected in reverse polarity. If you are using electrodes for aluminum arc welding, then pay attention to the current strength. This parameter should be set to a small value.

Follow our recommendations to get the job done efficiently:

If you need to weld thick parts, then the approximate location of the seam must be properly heated before welding. This is done using a regular gas burner.
Be sure to clean the seam of slag and pour boiling water over it.
Once the grout has cooled, clean it again using a stiff brush. Do not disregard this advice, as remaining slag can promote corrosion.

Popular brands of electrodes

As we mentioned earlier, a carbon electrode is often used to weld aluminum. But besides this, there are a number of brands that are no less popular among beginners and experienced welders. So, what electrodes can you use for welding aluminum with your own hands?

OK brand rods

These electrodes are manufactured by ESAB and are marked OK. We recommend using models 96.10, 96.20 and 96.50. Yes, they are not universal, but with their help you can weld technical aluminum or manganese-based aluminum alloys. These aluminum electrodes for welding at home have shown themselves to be on the positive side, but keep in mind that they require special care and strict adherence to the expiration date.

Rods brand OZA

In principle, such electrodes for welding aluminum with your own hands can be made, since they are based on simple aluminum wire. These rods are used for welding pure aluminum or its silicon alloys.

UANA brand rods

These are very highly directional rods used for welding cast aluminum alloys. They are practically not used in home welding, but we could not include them in our list.

EHF brand rods

EHF are tungsten electrodes; they must be used when welding with argon. It is difficult to make such electrodes for aluminum with your own hands, but if you have the opportunity to purchase them, be sure to try them in your work. Yes, with their help it is difficult to strike the arc correctly, and professionals often do not recommend such electrodes. But if you learn to hold an arc with such rods, then you will not have problems with all the others.

Manufacturing instructions

It doesn't matter what brand of electrodes you need to purchase, in any case it is not cheap.

Especially for beginner welders. We have found a solution to this problem and suggest you make the rods yourself. There are many videos on the Internet in which experienced craftsmen explain the technology for making materials for welding. We also decided to share our instructions on how to make homemade electrodes with your own hands. Follow these simple steps:

Prepare aluminum wire with a diameter of no more than 4 millimeters and cut it into rods 20-25 centimeters long. These parameters are usually sufficient, but you can change the diameter and length as you wish. Our base is ready.
Now let's prepare the coating. Grind up chalk (preferably regular white) and mix it with silicate glue (sometimes called “liquid glass” in stores). Mix everything thoroughly until smooth and dip the aluminum rods into it.
Make sure that the coating layer does not exceed 2 millimeters. Leave the electrodes to dry. When the coating hardens, the rod can be used for work.

Yes, such electrodes for resistance welding are inferior in quality to factory products, but they still allow you to perform simple work that does not require increased responsibility and a perfect seam. This instruction may seem too simple, but believe me, electrodes for spot welding on your own can also be effective and will absolutely save your money.

Please note that this is not a factory carbon electrode or zinc electrode, it is not European quality. So test your electrodes first before working on unwanted metal.

Instead of a conclusion

Now you know how to make welding electrodes with your own hands and what features you should consider before getting started. Be sure to try homemade rods and share your experience in the comments, it will be useful for other welders. Also share this article on your social networks. Good luck!

Source: https://svarkaed.ru/rashodnye-materialy/elektrody/elektrody-dlya-svarki-alyuminiya-svoimi-rukami.html

Technique for welding aluminum electrodes with an inverter at home

High strength, low specific gravity and affordable price have made aluminum one of the most popular metals. It is used everywhere from the aerospace industry to the production of household utensils.

Repairing aluminum products and creating your own structures in a workshop at home is complicated by a number of features of the metal.

Welding aluminum with an electrode at home using an inverter is one way to overcome these difficulties, which does not require expensive equipment or highly qualified workers.

Features of work

The melting point of the metal is 660°C . When heated, the atoms react with oxygen, forming a layer of refractory aluminum oxide with a melting point above 2200°C. This layer prevents the full formation of the seam.

Aluminum has high thermal and electrical conductivity. In practice, this means that in order to heat the workpiece metal, especially with large thickness, it will be necessary to use large operating current values.

The metal and its alloys are also characterized by high fluidity, which makes it difficult to work in a number of welding positions.

To prevent contact of the melt and oxygen in the air, gas welding is used . Helium, argon or its mixtures are supplied to the working area, displacing air and creating a protective cloud. This method requires expensive equipment and a constant supply of gas. It is cost-effective for large volumes of work.

For limited work at home, manual DC electrode welding is suitable. For this purpose, coated electrodes are produced that are optimized for use with thermally conductive materials.

What do you need to know to make a quality seam?

To obtain strong and durable connections, you need to know and consider the following points:

products made of aluminum alloys are always coated with a layer of refractory oxides;
before starting welding, this layer should be removed by mechanical stripping or etching;
the oxide layer is quickly restored in air, so the treatment must be carried out immediately before welding;
the color of the aluminum billet practically does not change when heated, it will not be possible to monitor the temperature visually;
When heated, the strength of the product decreases, this can lead to the appearance of microdefects during crystallization.

Taking these features into account allows you to avoid common mistakes when you need to weld aluminum blanks at home.

Is it possible with an inverter?

How to cook aluminum with an inverter and is it even possible to do it? This possibility exists. The use of coated electrodes makes it possible to work using conventional medium-power household-class inverters. Of course, such devices can only weld workpieces 3-4 mm thick. Thicker ones will require powerful semi-professional inverters.

Specifics

The inverter itself, used for welding aluminum workpieces, can be entry-level, household grade. Surface preparation, selection of welding materials and careful adherence to technology are of decisive importance .

Electrodes of the OZ series have excellent performance characteristics. But these qualities appear only at low humidity of the coating material. Therefore, before use, they must be calcined at a temperature of 120-140°C for 40 minutes. After calcination, the electrodes must be stored in an oven or in a special sealed case.

During work, you must be careful and careful. The high fluidity of the melt and its tendency to splash does not allow working in vertical and overhead positions . And in the lower welding position, it is recommended to use backing plates to prevent melt leakage.

To avoid thermal deformations during hardening, try to place the seams as far apart as possible.

What should the device be like?

There are no particularly specific conditions for the device . It must maintain a sufficient operating current for the selected workpiece thickness and electrode diameter. The operating voltage is set around 22-24 volts.

The device must support reverse polarity mode.

A large current reserve leads to an increase in size, weight and increased energy consumption.

If your plans for welding aluminum are large and such work is planned to be carried out constantly, then it is better to immediately purchase a device that supports the TIG mode, or welding with a non-fusible electrode in an argon or helium protective atmosphere. The electrode can be made of tungsten or graphite. This semi-automatic device allows you to cook with conventional fusible rod electrodes without gas supply.

Electrodes

The most popular electrodes used on aluminum for inverter welding are products from the following series:

OZA-1 . Used for welding pure aluminum workpieces. Before welding, it is necessary to remove the oxide layer and heat the surface to dry it.
OZA-2 . Used for surfacing with silicon-aluminum alloys. as well as for repairing defective castings.
OZANA-1 . For pure aluminum parts thicker than 10 mm. They need to be heated to 400°C.
OZANA-2 . Modification for welding aluminum alloys.
OKB96.20 . For work on aluminum alloys alloyed with Mn, Mg and Si. We can also use it on duralumin.

Covered welding technique

Welding of aluminum parts with an inverter is carried out using a current of reverse polarity, in the lower welding position . This is due to the high fluidity of the melt and the need to maintain a high speed of electrode movement

The electrode should be brought perpendicular to the seam line or with a slight tilt back. The trajectory of movement is straight, without transverse swings.

Operating modes for welding aluminum parts of different thicknesses.

The substances contained in the coating increase the resistance of the weld pool material to the passage of current, which complicates the re-ignition of the electric arc.

If the arc goes out, you should remove the slag layer from the crater and from the tip of the rod, and step back 1 cm . The remainder of the seam and the crater must be welded again to avoid porosity.

Upon completion of the seam, its surface is cleaned of slag and washed with water.

Rules for preparation and conduct

It is best to weld critical joints of aluminum workpieces using argon arc welding . The method using an inverter and rod fusible electrodes allows you to obtain quality sufficient for home repairs or construction. How to weld aluminum blanks at home using an inverter?

The strength and durability of the seam is largely determined by the quality and thoroughness of the preparatory work. They are designed to remove the layer of oxides with a high melting point that covers any part made of aluminum or its alloys upon contact with air.

The work is performed in the following sequence:

clean the seam area and the heat-affected area using a wire brush or angle grinder;
For cleaning, you can also use a chemical method by treating the surface with a reagent;
calcinate the electrodes to remove moisture from the coating;
if necessary, warm up the workpieces;
the hand with the torch should move at a constant speed along a straight path, without lateral swings.

Upon completion of the seam, it should be cleaned of the slag layer, thoroughly rinsed with water and dried. This reduces the risk of corrosion occurring and spreading.

Conclusion

Welding aluminum with a coated electrode is an affordable and uncomplicated method that can be used at home. To do this, you need to use an inverter, high-quality electrodes and follow technology.

Source: https://svarka.guru/tehnika/opredelennih-metallov/invertorom-alyuminiya-elektrodami.html