Mechanical treatment of metal: types and methods
Machining is a process, duringwhich changes the size and configuration of workpieces and parts. If we talk about metal products, special cutting tools such as cutters, broaches, drills, taps, cutters, etc. are used for their processing. All operations are performed on machine tools according to the technological map. In this article, we will find out what are the methods and types of metal machining.
Ways of processing
Machining is divided into two largegroup. The first includes operations that occur without removing the metal. These include forging, stamping, pressing, rolling. This is the so-called mechanical treatment by pressure or shock. It is used to give the necessary shape to the workpiece. For nonferrous metals, forging is most often used, and for black metals - forging.
The second group includes operations, duringwhich part of the metal is removed from the workpiece. This is necessary to give it the necessary size. Such a mechanical treatment of metal is called cutting and is performed with the help of metal-cutting machines. The most common processing methods are turning, drilling, sinking, grinding, milling, unfolding, chiselling, planing and pulling.
What determines the type of processing
Manufacturing of metal parts from billet -a time-consuming and rather complicated process. It includes many different operations. One of them is the mechanical treatment of metal. Before you start, make a technological map and make a drawing of the finished part, indicating all the necessary dimensions and accuracy classes. In some cases, a separate drawing is also prepared for intermediate operations.
In addition, there is a roughing, semi-finished andmechanical finishing of metal. For each of them, calculation of cutting modes and allowances is performed. The type of metal processing as a whole depends on the surface being treated, the accuracy class, the parameters of the roughness and the dimensions of the part. For example, to obtain a hole in the H11 grade, a roughing with a drill is used, and for a sweeping deployment to grade 3 accuracy, you can use a reamer or a countersink. Next, we will study the methods of machining metals in more detail.
Turning and drilling
Turning is performed on the lathe group machineswith the help of incisors. The workpiece is attached to a spindle, which rotates at a specified speed. A cutter, fixed in the support, makes longitudinal-lateral movements. In new CNC machines all these parameters are entered into the computer, and the device itself performs the necessary operation. In older models, for example, 16K20 longitudinal-lateral movements are performed manually. On turning machines, the shaping of shaped, conical and cylindrical surfaces is possible.
Drilling is an operation that is performed forobtaining holes. The main working tool is a drill bit. As a rule, drilling does not provide a high accuracy class and is either rough or semi-finished. To obtain a hole with a quality lower than H8 use deployment, reaming, boring and reaming. In addition, after drilling, they can also thread the internal threads. Such mechanical treatment of metal is performed with the help of taps and some types of incisors.
Milling and grinding
Milling is one of the most interestingways of processing metals. This operation is performed using a variety of milling cutters on milling machines. Distinguish the end, shaped, end and peripheral processing. Milling can be both rough and semi-finished, and finishing. The least accuracy is obtained by finishing. 6. With the help of mills, different keys, grooves, wells, cuttings, milling profiles are milled.
Sanding is a mechanical operation usedto improve the quality of roughness, as well as to remove the excess layer of metal up to a micron. As a rule, this treatment is the final stage in the manufacture of parts, and therefore, it is a finishing step. For cutting, abrasive wheels are used, on the surface of which there are a huge number of grains having a different shape of the cutting edge. At such processing the part very strongly heats up. In order for the metal not to deform and not to stick, use lubricating-cooling liquids (SORG). Mechanical processing of non-ferrous metals is carried out with the help of diamond tools. This allows to ensure the best quality of the manufactured part.