Since Whitney developed the first horizontal milling machine in 1818, the development of mill machine has gone through a long process. Starting from the ordinary milling machine, the evolution of vertical milling machine, lift milling machine, imitation milling machine and so on.
For more than a century, the development of milling machines to the current CNC milling machines, machining center, five-axis machining center and turning and milling complex processing center, the machinery industry has undergone a huge revolution. With the improvement of efficiency, some companies ignore some of the most basic principles of mechanical design: the material is a mechanical product of the most important and most can not be ignored. In particular, the German machinery products in the world has been in a very high position, it is because Germany in any product manufacturing process in strict accordance with the manufacturing process to produce. German companies have developed a step by step, according to the process to work habits. No matter how much innovation and change has taken place in the machinery industry, German companies are not going to work according to rules. I think this is the world has been produced in Germany to give a high evaluation of the reasons for the product.
Some companies in order to improve production efficiency and ignore the strict control of the material. Especially machine tool products, the initial business have to go through a year of aging, it is very important. Because the milling machine casting after a year of wind and sun, material organization will be subtle changes. This is a natural age. Later, in order to simulate the natural aging, to take a manual aging approach. In order to eliminate the use of precision measuring tools, molds or parts in the long-term use of the size, shape changes, often after low temperature tempering (low temperature tempering temperature 150-250 ℃) before finishing, the workpiece reheated to 100-150 ℃, -20 hours, this kind of stability for the quality of precision parts processing, known as aging. The aging treatment of steel members under low temperature or dynamic load conditions to eliminate residual stresses is particularly important for stabilizing steel structures and sizes.
Aging treatment refers to the alloy workpiece by solution treatment, cold plastic deformation or casting, forging, at a higher temperature or room temperature, its performance, shape, size changes over time heat treatment process. If the use of the workpiece to a higher temperature, and a shorter time for aging treatment process known as artificial aging treatment. If the workpiece placed at room temperature or natural conditions for a long time storage and the aging phenomenon, known as the natural aging treatment. The third way is the vibration aging, from the early 80s gradually into the use phase, vibration aging treatment in the absence of heating is not as time-consuming as the natural time, to the workpiece to exert a certain frequency of vibration to the internal stress to be released, thus To achieve the purpose of aging. The purpose of aging treatment is to eliminate the internal stress of the workpiece, to stabilize the organization and size, to improve the mechanical properties.
In mechanical production, in order to stabilize the casting size, often castings at room temperature for a long time before, and then cutting. This measure is also called aging. But this aging does not belong to the metal heat treatment process.
Materials through these processes in order to ensure the stability and accuracy of the mill machine. Or the machine is only in the production of the initial inspection is qualified, but after the transport, debugging time changes the accuracy of the machine also changed. So a machine tool no matter how you use a very high-precision system, once the material organization is unstable, the machine accuracy is not stable.