Precision machining is a process that uses processing machinery to change the shape or performance of a workpiece. According to the temperature state of the workpiece to be processed, it is divided into cold processing and hot processing. Generally processing at room temperature, and does not cause chemical or phase changes of the workpiece, it is called cold processing. Generally, processing at higher or lower than normal temperature will cause the chemical or phase change of the workpiece, which is called thermal processing. Cold processing can be divided into cutting processing and pressure processing according to the difference in processing methods. Thermal processing commonly includes heat treatment, forging, casting and welding.
Precision machining is realized by using precision machine tools, precision measuring tools and measuring instruments under strictly controlled environmental conditions. Machining accuracy of 0.1 micron or more is called ultra-precision machining.
Here is an introduction to the five major processes of precision machining.
1. The geometric shape and mutual position accuracy of the parts reach the micron or arc second level;
2. The limit or feature size tolerance of the part is below micron;
3. The microscopic unevenness of the surface of the part (the average height difference of the surface unevenness) is less than 0.1 micron;
4. Mutual accessories can meet the requirements of coordination;
5. Some parts can still meet the requirements of mechanical or other physical characteristics, such as the torsional stiffness of the torsion bar of the float gyroscope and the stiffness coefficient of the flexible element.