High-tech and efficient technologies – plasma cutting and laser processing
Among modern methods of metal processing with high productivity and efficiency, laser and plasma cutting are distinguished, which do not act mechanically on the surface, and laser beam and plasma jet, respectively, are used as cutting tools. These technologies are widely used in many industries due to their versatility and a huge range of processed materials. The flow of plasma can be cut any metals and alloys (including refractory), as well as concrete, stone, etc., the laser is suitable for processing a variety of names of non-metallic materials and certain metals.
Basic principles of plasma cutting
The technology of plasma cutting is based on the features of gases in the ionized state becoming conductors of the electric current. Air or other gas used is ionized in the plasma torch under the influence of high temperature. The spark generated in the electrical circuit ignites the heated gas, forming a stream of plasma, which is the cutting tool for this method of processing materials. There are two types of plasma cutting: in one case an electric arc arises between the electrode and the tip of the plasma torch, in the second – between the material being cut (necessarily conductive) and the electrode.
Plasma jet, characterized by high electrical conductivity, escapes from the nozzle at a tremendous speed. A stream directed to the workpiece locally heats the material and melts it, dividing it into parts at the cutting site.
How laser cutting happens
When processing materials with a laser beam energy is used, concentrated in a narrow beam. The high-density light flux, when it hits the surface, heats it at the point of contact to the temperature causing the destruction. Thus, the beam burns the material through or melts it exactly along the cutting line, the remaining areas are not deformed, retaining its structure and shape.
Comparative characteristics of laser and plasma cutting
To determine which of the technologies is most preferable, you should compare the results of cutting the same materials. With a small metal thickness and a simple cutting configuration, the laser and plasma have roughly the same performance and quality characteristics, but with increasing depth of processing, plasma cutting is more preferable. This type of processing is most suitable for cutting simple parts from a sheet of large thickness.
If it is necessary to produce a complicated contour cutting with the implementation of a number of holes, grooves and grooves, and also to produce large batches of the same type of parts, laser equipment will be indispensable. Plates made of plasma (especially small diameter), internal corners and other curved contour elements can have minor distortions in geometry, which are absent in laser cutting. This is because the focusing of the laser beam is much smaller than the diameter of the plasma jet. Preparing the cutting scheme when using plasma, you should take into account the thickness of the cut (1 – 2 mm) and do not place the parts too close to each other. In the case of laser processing, such allowances are not needed, since the cut line is a fraction of a millimeter. The laser beam guarantees accurate, stable cutting and excellent edge quality, while the plasma can leave scales on the edge (which is easily removed with additional processing).
As we see, both technologies have both advantages and disadvantages, and their economic efficiency depends on many factors. Advantages of both methods is the absence of mechanical contact between the cutting tool and the surface to be treated and the effect of thermal action in the local zone, which excludes deformation of the material outside the cutting line. Plasma cutting surpasses laser technology in the speed of operations and wins by the level of energy costs when working with materials with a thickness of 6 mm to 20 mm. Plasma can be used for simple cutting and thicker metals, providing an optimal balance of quality, productivity and operating costs. Figured cutting of thin and ultrathin materials is best entrusted to the laser, which guarantees high accuracy of the resulting parts, regardless of the complexity of the configuration and the number of small elements.