Learning how to cook aluminum is quite difficult. Often, such work is not taken even the master with experience. The problem is that aluminum is a very capricious material and working with it requires the use of a high quality inverter.
The process of electric welding of aluminum.
Of course, you can get by with almost any semi-automatic welding machine, but really high-quality welds allow you to get only devices that have a special function of welding this metal. If the appearance also matters, then it is better to boil aluminum with an aggregate with a special option of pulsed welding. Aluminum is usually boiled in argon. Modern inverters allow you to do everything efficiently and in the shortest possible time.
What requirements must be observed when welding aluminum with argon?
When boiling aluminum, pure argon is usually used. You can use a mixture of this gas with helium. The second option is better suited for working with thick sheets. Aluminum is boiled using special aluminum wire with a solid cross-section.
It is important to pay particular attention to the design of the burner. First, it must be installed on a straight hose, without any twisting or kinking. Secondly, the length of this hose should be no more than 3 m. The problem is that aluminum is boiled with argon using very soft wire. Instead of the usual channel, it is better to install teflon in the burner, designed specifically for working with aluminum.
In case there is not enough 3 m of hose for you, bring the welding inverter closer to the material being processed. If this is not possible, it will only be possible to boil aluminum with argon using an aggregate with a separate feed mechanism. The tips should have a larger diameter than for steel. This is due to the fact that when heated, aluminum expands more.
Oscillator circuit for aluminum welding.
Need to pick the right electrodes. The best results are shown by welding aluminum with argon using such electrodes:
- OK 96.20, OK 96.10.
- OZANA-1, OZANA-2.
- Non-consumable products on a tungsten base.
The first brand of electrodes was widely used a little more than 10 years ago. Such electrodes are mainly used for working with technical aluminum. They can also be used for welding alloys and foundries. They allow you to maintain a steady arc. The properties of the finished seam are as close as possible to the properties of the source material, and the slag crust is removed without any extra effort.
At the electrodes of the 2nd type there is an alkali-salt coating. They are used when working with a variety of aluminum alloys. In most cases, it is necessary to carry out preheating on average up to 200-300 ° C.
Boil aluminum with argon using non-consumable tungsten electrodes. They allow you to maintain an arc at a stable level. Such electrodes may have a diameter of 2-6 mm. For each case, you need to select the appropriate diameter of the electrodes in a separate order. It depends primarily on the thickness of the processed product. Tungsten electrodes with various additives are most effective.
Scheme of argon arc welding of aluminum.
When aluminum is boiled with argon, rather expensive electrodes are used, so their choice should be approached with skill and must take into account the peculiarities of the work ahead.
To boil aluminum with argon, you need the following:
- Welding machine and suitable electrodes.
- Aluminum wire.
- Gas welding and heating device.
Main features of aluminum welding
The main difficulty of aluminum welding is an oxide film formed on the metal surface during processing. The melting point of this film reaches 2050 degrees, and aluminum directly melts at much lower temperatures.
In accordance with the technology, you must first punch through this film, and after that, directly melt the metal. The best way to perform this task is pulsed welding. Aluminum has good thermal conductivity and a low melting point. Because of this, in the process of carrying out welding workpiece can ignite. To avoid this, you need to preheat the preform slightly. This will additionally increase the penetration depth of the aluminum part.
Schematic diagram of the post for semi-automatic welding with consumable electrode: SG - welding torch, P - balloon reducer, B - cylinder with compressed gas, MP - welding wire feeder, BU - control unit of the semiautomatic device, PI - power source.
To make it easier to break the oxide film, you need to pre-process the part with a metal brush. Such processing will not take much time, but the part will be melted better and faster. Cleaning is recommended immediately before the start of welding.
In the process of welding aluminum, make sure that the arc had a constant length. This rule is relevant not only for aluminum, but also for any other metals. If the arc is longer than necessary, the billet will not melt. If it is shorter, the metal will ignite. A suitable arc length is determined taking into account the chemical composition of the material, since in different alloys, thermal conductivity also differs. On average, in the case of aluminum, an arc of 1.2-1.5 cm is used.
Another difficulty that you will encounter during the aluminum melting process is brewing a crater at the end of the seam. The problem arises from the fact that aluminum cools quickly enough. To solve this problem allows a special semi-automatic. First, it gives an increased current, which allows you to break through the oxide film. In the future, the current decreases, which makes it possible to weld the crater mentioned above without any problems.Back to table of contents
What welding methods exist
Classification of the main types of welding.
For aluminum boiling, many different ways have been developed, involving the use of various materials, equipment and protective media.
The most widely used the following methods:
- Inert gas welding using a tungsten electrode.
- Welding using a semi-automatic with automated wire feed.
- Welding consumable electrodes without protective gases.
An important condition for this work is the destruction of the oxide film formed on the surface of aluminum. For its destruction suitable alternating or direct reverse current. Aluminum can not be cooked in direct current, because in such conditions, the oxide film will not succumb to cathode sputtering and will not collapse.Back to table of contents
What devices are suitable for aluminum welding
Welding transformer for arc welding.
For welding aluminum with argon, you can use a number of welding machines. All of them are divided into several groups, namely:
- Universal units.
- Special models.
- Specialized equipment.
Universal models are manufactured in series, they are most in demand among buyers and are used most often. Similar welding is applied in production conditions on specially equipped platforms.
For welding aluminum in argon, you can use various special additives. They make the work more simple and quality.
Units that allow aluminum to be boiled with argon using non-consumable tungsten electrodes have the following equipment:
- AC / DC source.
- A torch or a set of devices specifically designed for this kind of work.
- A device capable of providing starting arc reinforcement or one that allows stabilizing a variable arc.
- Equipment that allows you to control the welding cycle.
- A device designed to compensate and control DC.
Diagram of the process of aluminum welding semiautomatic.
Currently, there are a number of new methods of aluminum welding with argon, designed specifically to expand the range of thickness of materials that can be cooked, improve performance indicators in obtaining welding compounds, including improvements in penetration.
In the process, the arc moves in steps or at a certain speed. These movements can be synchronized with welding current pulses. Due to this, the penetration will be the most effective in all areas. Reducing the current eliminates the risk of overheating of the metal and due to this almost completely get rid of the deformations.
Tungsten electrodes allow to obtain high-quality welds and perform work at a rather high speed. To perform the work, you need only special equipment and additional units, no hard-to-reach and expensive units are needed.
Most often, argon welding is performed using an inverter unit. Such devices are widely used both in everyday life and in production. The use of inverter welding machine is the best option. Even without special experience in welding, you can understand the technology without much effort. And this knowledge will definitely be useful to you. First, you will be able to perform your personal tasks, and secondly, if you wish, provide services to third-party customers.Back to table of contents
Step by step welding instructions
Scheme of the device welding semiautomatic.
Aluminum welding with argon has a number of unique features. The heart of the torch, which is used to perform such work, is made of a tungsten-type welding electrode. The electrode itself is surrounded by a ceramic nozzle. When working from it will come out argon.
If you try to boil aluminum without using argon, it may catch fire, an active oxidation process will begin and the electric arc will be interrupted. When working with aluminum, it is necessary to monitor the argon consumption and adhere exactly to all the requirements of the technology for performing such welding.
First, the mass is fed to the machining part. For this, a welding machine is used. Everything is done the same way as in ordinary electric welding. The operator takes a special aluminum wire in his left hand, and a device burner in his right. The wire is selected taking into account the characteristics of the welded material.
After the operator presses the button, the current turns on and the gas supply starts. An arc will appear between the welding electrode and the workpiece. The arc will melt the edge of the part and the filler wire directly. It is at this stage that the formation of the weld occurs.
For people with experience in this process there is nothing difficult. The technology has been tested by many masters and its effectiveness has been proven over the years of successful use. But in order for welding to be of the highest quality, you will have to practice a little. In addition, to obtain a good result, you need to select the appropriate apparatus. From the budget models of dubious production it is better to immediately abandon.
To learn how to weld aluminum parts, you have to spend some time. Consider and how presentable appearance should have a ready connection. For example, if you need to weld hinges to the garage doors, then you can not take special care.
Thus, aluminum welding is a rather time-consuming and extremely important operation, which requires a competent and thoughtful approach. Cook according to the instructions and you will succeed. Have a good job!