Generally speaking, according to the machining accuracy, machining can be divided into three stages: general machining, precision machining, and ultra-precision machining. At present, precision machining refers to a machining technology with a machining accuracy of 1~0.1μm and a surface roughness of Ra0.1~0.01μm. However, with the advancement of processing technology, this limit is constantly changing. Today's precision processing may be general processing tomorrow.
The problems to be solved by precision machining are: one is machining accuracy, including form and position tolerance, dimensional accuracy, and surface conditions; the other is machining efficiency. Some processing can improve accuracy, but it isn't easy to achieve higher processing efficiency.
Ultra-precision machining refers to a process in which ultra-precision machine tools use strictly constrained relative movement between parts and tools to cut a small amount of material to obtain extremely high shape accuracy and surface finish. The current ultra-precision machining refers to the machining technology in which the dimensional accuracy of the machined parts is greater than 0.1μm, the surface roughness Ra is less than 0.025μm, and the resolution and repeatability of the machine tool positioning accuracy are greater than 0.01μm. Also known as sub-micron level processing technology, and is developing towards nano-level processing technology.
Ultra-precision machining includes micro-machining, ultra-precision machining, finishing, and other processing technologies.
Micro-processing technology refers to the manufacturing technology of manufacturing tiny parts. Ultra-fine processing technology refers to the manufacturing technology of manufacturing tiny parts. They are proposed for the manufacturing requirements of integrated circuits.
Finishing generally refers to a processing method that reduces the surface roughness and improves the mechanical properties of the surface layer. Typical machining methods include honing, grinding, superfinishing, and chip-free machining. These processing methods can improve the surface quality and improve the processing accuracy. Finishing is a new term put forward in recent years. It not only refers to reducing the surface roughness and improving the mechanical properties of the surface layer but also refers to the processing method that improves the processing accuracy (including the size, shape, and position accuracy).