Metal cutting is performed so that the workpiece takes the desired shape. To this end, it is necessary to remove the excess. Such manipulation is carried out through the use of different cutting tools on special machines. In mechanical engineering, metal cutting is very important. Indeed, without this process, neither ordinary machines nor other devices can be made.
Technology application
Cutting metal by cutting is practiced during the initial peeling work and in the final operations, which are called fine processing. Indeed, such actions sometimes need to be performed, observing high accuracy: up to fractions of a micron. And this is a very small value.
Metal cutting is also practiced for large machine parts. For example, for rotors of hydroturbines. The diameter of their impellers may exceed the mark of 9-10 meters. Also details that are difficult to see even under a microscope lend themselves to cutting. Through processing, the element receives the desired shape, size, and acquires the necessary surface quality. The product service life depends on this indicator.
Cutting theory
Such a science studies the cutting of metal in a similar way. She appeared at the end of the XIX century. Until now, they are engaged in it both in Russia and abroad. The key issue is the chip removal speed by means of the machine, so that the cutter resistance is maximum. It may seem to many that achieving high speeds is not so difficult. But this is not so. The thing is that metal cutting develops heat. It heats and softens the tool for work, at the risk of incapacitating it. It is very important to choose the right cooling for the cutter. But it does not always solve the problem. In addition, it can even damage the metal. Therefore, the speed of work depends in part on how correct the machine was chosen. Tools for metal cutting should be purchased taking into account the properties of the material and its properties.
Features of the use of machines
Metal cutting machines are divided into types. They differ in the tool used. Also, the technology of metal cutting with their help is different. The most commonly used cutter. With it, you can perform operations of any complexity. All other tools are either its modification, or a combination of several types. There are two most common schemes of work:
- turning when the workpiece rotates and the cutter slowly moves along its axis;
- planing - they are both progressive movements.
Machine tools for them are absolutely different.
Features of metal cutting
As mentioned earlier, the process in question may occur atypically. And there are different methods of metal cutting, which provides for the use of one or another equipment.
In addition to turning and planing, common methods of work include milling and grinding. However, the first method is the most popular.
The mechanical processing of metals by cutting by various methods has much in common with sharpening. Therefore, if you learn this method, then with the rest in the future there will definitely not be any problems. And everything will be very simple in terms of work. Below are the features of using different types of machines.
Lathe Application
Equipment for cutting is different. One of the key types of machine tools is turning. Its use was practiced in ancient times. Then it was powered by rope devices like a bow for shooting. In a field such as metal cutting, turning is currently used to manufacture machine parts. Moreover, this is done so accurately and quickly that it will not be possible to achieve such goals mechanically.
The base of this type of machine is a bed. The workpiece must be clamped between the centers of the tailstock and the headstock or in the cartridge. Reinforce the cutter in the caliper. Set by means of a special box resembling a car, the required rotation speed for cutting. The tool has a running roller, which comes in motion from it and displaces the caliper along with the cutter. If in addition to it there is a lead screw, then by means of such a machine it is possible to perform cutting. When a swivel head is present instead of the tailstock, the tool is called a turning-revolving tool. Such a cutting machine can perform various types of work. To process products with a large diameter, tools such as a front-turning or rotary-turning machine are used. There are other types of it.
Increased lathe durability
Specialists are constantly working to find suitable materials that can increase the resistance of the working tool for cutting metal. Previously, machines were made on the basis of simple carbon steels, which have a simple composition in terms of chemistry. After that, materials with a high tungsten content began to be used. With their help, it was possible to cut metals much faster. Therefore, they began to call them high-speed. However, they also ceased to satisfy specialists in the field of mechanical engineering over time.
Then, when they created the machines, they were replaced by carbides of a special class, which are able to maintain strength even at temperatures up to 100 degrees. In recent years, the process, which is based on metal cutting, has become even easier. This was achieved through the use of materials with maximum resistance to high temperatures. Depending on the initial hardness of the workpiece, such as a cutter, as well as the type of work, it can be processed at the desired speed, which is regulated by means of a special box.
Milling as a type of metal processing
This method of work is quite widespread and quite high-performance. It is carried out using a special milling machine. CNC machines (numerical control) are used more and more often. Depending on the location of the support, they are divided into several types:
- vertical
- horizontal
- portal
- longitudinal;
- gear hobbing;
- multi spindle;
- single spindle and others.
Specialists in the manufacture of equipment of this type are constantly improving it so that the productivity of metal processing is higher. The material of the machines is constantly changing, its design is also changing. Like the cutter when planing, the cutter performs similar actions. But at the same time, it combines several of its types. And it will work more productively. Due to this, milling significantly exceeds planing and gradually displaces it in production.
Grinding features
Machines for this type of processing are used for grinding inside and outside surfaces of round shape, different planes, centerless machining, carving, gears and much more. Such a tool for metals is classified as the most productive. In addition to a special machine, there is another device. This is a grinding wheel, which includes a large number of small cutting elements. They, in turn, are fastened with a special binder. And each particle in itself is a cutter. As you can see, we examined the equipment for metal processing. Below we will familiarize ourselves with more modern techniques that allow it to be cut.
Features of plasma cutting technology
There are several techniques used for low carbon metals. But plasma cutting is considered one of the most productive. Therefore, its features and advantages should be addressed in more detail. Process technology is rapidly and constantly evolving. Plasma cutting of metals is widely used in various industrial fields: from the construction of houses to mechanical engineering. Along with the oxygen-gas method, it is considered quite promising.
Key Benefits
The plasma cutting method of metals has a large number of advantages. One of them is the speed of work. Most often, blanks for cutting have a thickness of up to 25 mm. In this case, their processing speed is approximately two times or even more than the same when using oxygen-gas type cutting. And it is worth adding that with a noticeable decrease in the thickness of the sheet of metal, it can exceed it by 12 times. Such advantages can significantly increase productivity and save time.
Another advantage of the method is a high and high-quality burning speed. This characteristic is very important when cutting metal products. With the plasma method, it is about 2 seconds. For comparison: gas cutting with oxygen - 30, respectively, subject to a temperature of 1,000 degrees at least. A brief interaction of the tool with the metal is good, first of all, because in a couple of seconds the material will not have time to deform, as this can happen in another case.
Another undoubted advantage of the plasma method is the minimum amount of dross during operation. It can be easily removed. Cutting systems are also easy to control and help ensure the right tool height and good speed.
Save time and money
Plasma cutting also means working simultaneously with multiple sheets, which saves time. With this method, you can process different types of materials:
- aluminum;
- stainless steel;
- copper and more.
It should be noted and the safety of the use of plasma systems. They do not use combustible gases for work, open fire, a lot of heat is not released. All this significantly reduces possible risks for users when working with hot metals. The heat affected area is only 2 millimeters.
All characteristics of plasma cutting have a positive effect on costs in the secondary processing of materials. The work is carried out efficiently, quickly and universally. To solve many problems, the listed advantages are most preferable than others.
Features of the laser method
To date, many technologies have been introduced in the field of processing metal products. They can greatly facilitate the work of designers, builders and other specialists whose work is somehow related to this process. Laser cutting is currently considered the most advanced. It allows you to get great opportunities in the manufacture of metal products in terms of design and various configurations.
Such a promising technique is quite young, but is already widely distributed. Laser cutting of metal is carried out through focused technically powerful special installations. They are distinguished by high radiation concentration. And they are able to cut not only aluminum or copper, but also wood and other materials.
Method Description
With this cutting method, oxides appear on the metal surface. They increase the energy absorption process and are able to maintain the temperature to the melting point. In the contact place, the laser beam creates maximum temperature indicators, as a result of which the material begins to melt. But outside the specified zone, it only heats up. At the same time, active gas is supplied, most often it is oxygen. It blows combustion products and can significantly increase the cutting speed. Oxygen heats several layers by removing liquid metal and oxides.
All this happens while the material is not cut through to its entire depth. After all, a gas stream near the separation lines is able to actively cool it. A small heat-affected zone can provide the creation at small distances from each other (of the order of 0.2 mm) of edges located in parallel. Very often, in order to achieve one or another accuracy during the cutting operation, it becomes necessary to introduce automated control by computer. In such cases, you can program the creation of a product in a finished form.
For laser cutting of sheet metals , equipment based on solid-state and gas tools is most often used. The slice of the material is perfectly flat. No machining of metals by cutting can provide such accuracy, taking into account the operational performance and with a minimum amount of waste. Basically, for processing sheet metal, devices based on gas and solid-state lasers are used. The laser cut of the metal will be perfectly smooth. It will turn out without deformations that are present during a mechanical cut. In addition, laser cutting technology allows you to achieve significant accuracy, minimal waste and quick execution.
Method Advantages
In the market for cutting metal products, laser cutting is one of the most popular. She has largely made working with carbide materials simpler. After all, they are quite complex in terms of processing and often could deteriorate after such manipulations. For laser cutting are best suited:
- steel;
- non-ferrous metals;
- aluminum alloys.
Thick sheets are also much better processed. It will be easier to work with complex shapes of metal parts and make holes in very hard materials with a small diameter. Here in terms of geometry you can give free rein to your imagination. The system can be automated. It is enough to create a special file with the specified program on the computer. There will be no mechanical effects on the metal - this is also important. Also, during laser processing, the following advantages were noticed:
- The ability to create a complex contour of the cut.
- You can process almost any sheet metal regardless of its thermophysical characteristics.
- High precision work.
- Cutting is possible even on easily deformable and not too rigid materials.
- High productivity through the use of high laser power.
- If the surface should be smooth, it is better to use a focused beam with adjustable power.
Gas way
Consider a fairly common method of exposure to metal, which has been actively used for many years. This is gas cutting. It is quite popular and cost effective. In another way, it is also called oxygen, since in this case the process of exposure to the metal has a thermal nature. There is a stream of oxygen after the end of work and removes residual liquid oxide. To begin with, the upper edge of the part is heated. Depending on the chemical composition of the material (such as steel), its ignition temperature can range from 1000 to 1200 degrees.
Gas cutting can be used to treat medium alloyed, low alloyed or carbon steel. The thickness of the metal sheet or other product should be a maximum of 300 millimeters. The gas-oxygen metal processing technique has its advantages:
- Low processing costs.
- There is no need to work with the edge after the procedure is completed.
- The presence of direct and diagonal cutting of products at different angles.
- Thick metal sheets can be used.
Is there a work standard?
Many people wonder whether metal processing has GOST or other standards regarding the processing of structures. So, according to existing rules and criteria, such a process has its own tasks. First of all, the details should be given one or another configuration and dimensions. This is required by the used technological documentation. For example, an approved project for the construction of an object. Also, the surface to be treated must always be clean in accordance with accepted standards. GOSTs list mechanical methods for processing metals by cutting, including turning, drilling, milling, as well as chiselling, drawing. The final processing of products is also indicated. Each type of metal machining corresponds to not only certain equipment, but also a serial number.
As we saw, there are many ways of mechanical and automated processing of products with the aim of cutting them. All this is widely used in construction, engineering, repair and other fields. Techniques are constantly being improved and supplemented by new ones, modern equipment is being created, which every time makes the process more and more simple.