The development prospect of precision machining and ultra-precision machining
Machining
The development trend of precision machining and ultra-precision machining From a long-term development concept, the manufacturing skills of its equipment were the primary strategy and direction of the development of the national economy in the world at that time, and it was one of the important means of a country's economic development. At the same time, it is also a long-term plan for a country to be independent, prosperous, continue to develop economically, and adhere to the lead in science and technology. The development of science and technology also puts forward higher requirements for fine machining and ultra-precision machining skills.
The high-power and high-precision machining and ultra-precision machining of precision fine machining can achieve extremely high surface quality and surface integrity to a certain extent, but it can be guaranteed at the expense of processing power. When the drawing method is used for processing, the maximum deformation force is only 17t, while when the cold extrusion method is used, the deformation force is 132t. At this time, the unit pressure acting on the cold extrusion punch is more than 2300MPa. In addition to high strength, the mold also needs to have sufficient impact toughness and wear resistance.
The precision-machined metal blank undergoes intense plastic deformation in the mold, which will increase the mold temperature to about 250°C to 300°C. Therefore, the mold material requires a certain tempering stability. Because of the above, the life of cold extrusion dies is much lower than that of stamping dies.
Precision machining seeks high reliability of products to a certain extent. During operation, parts such as bearings that are subjected to load while doing relative motion can effectively reduce their surface roughness during operation, which can improve the resistance of parts. Wear resistance, improve its working stability and prolong its service life. Si3N4 used in high-speed and high-precision bearings. The surface roughness of the ceramic ball is required to reach several nanometers. The chemical properties of the processed metamorphic layer are active and susceptible to corrosion, so from the perspective of improving the corrosion resistance of the parts, the metamorphic layer produced by processing is required to be as small as possible.