in recent years, with the continuous development of social economy, precision machining and ultra precision machining technology has become the forefront of mechanical manufacturing technology. It reflects the level of mechanical processing in a country, and it is a new technology. In the past thirty years, the machining precision has been improved by an order of magnitude by modern advanced technology and technology, and it is now moving from micron and submicron to nanometer precision. Nowadays, both in the field of science and in the field of production, this technology has been applied in a necessary way. The importance of this technology is self-evident, directly related to the development process of craft.  

    as we all know, in real life. There are three forms of machining: general processing, precision machining and ultra precision machining. Ordinary processing refers to the precision of the general technical level. Precision machining refers to the precision that can be achieved through high precision machining tools or instruments and advanced processing techniques. Ultra precision machining means that the precision of the advanced machining technology must be finished by experiments, discussions and research. The precision indexes of each period are different, so the three forms of processing will change with time. The ultra precision machining technology is measured by the highest processing precision that can be achieved at every historical period. As long as it exceeds this standard, we can call these processing methods ultra precision machining technology. As far as the current standard is concerned, the machining precision of precision machining technology is 1 0.1um surface roughness of Ra0.2 1 0.01um, and the machining precision of ultra precision machining technology is higher than 0.1um, the surface roughness R is less than 0.25um, and the resolution and repeatability of the positioning precision of the machine tool are higher than that of 0.01um.

    ultra precision manufacturing technology has been widely applied in the world. The attitude bearing and telemetry components, such as artificial satellite bearings and telemetry parts, the Harbert telescope (HST) sent into space, the rotor blades of the aircraft engine, etc. related to the defense industry; processing of silicon related to the integrated circuit (IC) (the machined surface roughness of silicon is generally less than 2nm, maximum 0.1nm); in addition, lithography equipment and silicon chips are added. The accuracy of the equipment is required to sub micron and nanometer level. The precision of the missile inertial instrument, the precision of the plane reflector of the laser gyro and the missile reflector of the infrared guidance are all required to reach the nanoscale level. In addition, the manufacturing accuracy requirement of optical non spherical surface parts has reached λ / (30— 50), the surface roughness required ≤ 0.5nm.

    ultra precision machining will be developed in the direction of high precision, high efficiency, large scale, miniaturization, intelligentization, process integration, integration of on-line processing and testing, green and so on.