New technologies for processing solid-state materials can quickly and efficiently cope with almost any structure. Metal can be easily cut using abrasive and laser devices. Even traditional mechanical heads with diamond discs provide high-quality cutting of thick sheets. One of the most effective ways to solve such problems is plasma cutting of metal. The photo below illustrates this process.
Technology Overview
The technique is specifically designed for metal processing without the use of sawing tools. Like other thermal cutting techniques, this method consists in creating a cut in the structure of the material by means of the point impact of the beam on the working section. Direct plasma cutting is carried out due to thermal radiation, the source of which is a special tool. As a rule, this is a machine equipped with a plasma torch.
In general, the process resembles classical welding, but there are fundamental differences. For example, the blowing of air currents as a result forms a cavity with a molten mass. A base prepared in this way is more malleable, therefore, plasma cutting enables the operator to receive cutting with high accuracy regardless of the parameters of the workpiece.
Plasma cutting application
Equipment for plasma processing allows you to perform operations with blanks of non-ferrous and ferrous metals. Also, depending on the device, the user can cut alloys and refractory workpieces with a thickness of about 40 mm. This technology is successfully used in art workshops. In part, this area of use of such tools can be compared to forging. Specialists carry out original decorative products for decorating gates, fences and furniture. The manufacture of objects with a curved cutting line also allows plasma cutting. The photo below shows an example of figured processing.
In addition to creative directions, the method is used in factories, as well as in the construction industry. Plasma can process any metals that conduct electric current. In some areas, it is not so much the cutting of workpieces that is important as the processing of the edges. Similar operations also perform plasmoresis.
The principle of plasmoresis
The process begins with the formation of an electric arc between the workpiece and the electrode in the plasma cutter . Sometimes a separate ignition occurs in contact between the nozzle of the apparatus and the electrode. The formation of a plasma stream is realized due to the gas supplied to the head of the device. Further, under high pressure, an electric arc is generated with a temperature regime of about 15,000 ° C. Depending on the characteristics of the material, one or another gaseous medium is used. For example, cutting sheet metal with plasma using hydrogen or nitrogen is suitable for non-ferrous grades. On the other hand, oxygen will be the best option for processing ferrous metal. In the process, the operator requires full control of the active jet. Immediately after the activation of the electric arc, the production of a standby plasma flow begins. By controlling the apparatus, the user adjusts the parameters of the formed torch, directing it to the cut line in the workpiece.
Types of cutting equipment
As a rule, plasma cutters are divided into transformer apparatuses and inverter-type devices. The first group is represented by models specially designed for cutting metal sheets with a thickness of 35-40 mm. Inverters are modest in size and at the same time higher performance compared to transformers. However, high quality processing at lower energy costs is provided only in cases where plasma cutting of metal is carried out, the thickness of which does not exceed 30 mm. Also, the devices differ in the type of nozzle cooling system - in particular, there are liquid and air models. In the first case, the cooling medium is a jet of water, and in the second, a gas. In large aggregates, water is often used, which allows to increase the accuracy of operations. In order to ensure a high working resource, technologists recommend the use of gas cooling systems.
What is the advantage of plasma cutting?
Typically, competition between solid state cutting technologies occurs in terms of accuracy and cutting speed. However, the advent of new methods has expanded the possibilities of processing, increasing the basic requirements for the quality of operations. By the totality of operating indicators, plasma cutting is one of the most profitable technologies of this type. This is primarily due to the possibility of local point cutting without deformation of the surrounding zone. Even plasma cutting of stainless steel is performed without thermal deformation of the workpiece, although a high power apparatus is required to process such a material. In addition, the high cutting speed is emphasized. If you select the appropriate amperage, then a thin sheet can be dealt with in a matter of seconds without losing quality.
What to consider when choosing a plasmoresis?
As already noted, in the choice of the device, the current strength of the apparatus is of considerable importance, which will allow to cope with a particular grade of metal. For example, 40-50 Ampere models are suitable for working with brass, copper, aluminum and other non-ferrous metals, but their potential is not enough for high-quality and confident steel cutting. To work with ferrous metal grades, it is desirable to initially focus on devices whose current strength is at least 100 A. And this is without taking into account the thickness of the workpiece. As a rule, plasma cutting is performed at the rate of 5 A per 1 mm. It is also worth considering the duration of the active work of the plasma cutter. For representatives of the initial level, for example, this interval is no more than 10 minutes, after which the operator has to take a technical break.
Conclusion
With all the advantages of plasma processing technology, it is not the best way to cut metal. For example, the waterjet technique is distinguished by the ability to perform cutting in workpieces of virtually any thickness. At the same time, the equipment is cheaper to maintain and requires minimal energy consumption. In turn, plasma metal cutting offers high speed and the corresponding quality of the result. Most importantly, the technical organization of this process involves only the acquisition of a special apparatus. Anyone can use a plasma cutter in everyday conditions - but, of course, with proper preparation. For comparison, an abrasive operation is not complete without the use of massive aggregates that supply jets of water or air mixed with sand particles.