With the continuous development of precision processing technology and large-scale applications, people have put forward higher requirements for product performance and quality. Product performance and quality are mainly implemented based on product design, and then precision processing equipment and assembly Process to ensure the realization of its quality. The quality of precision hardware parts usually includes the accuracy of the product and the surface quality of the product. The surface quality of precision machining is a very important indicator, especially after high-speed and high-temperature processing. Under high pressure conditions, its reliability may have a very large impact;

    The surface quality of the product processing is to change the appearance size, shape and performance of the blank through precision processing equipment or other methods, so that it can meet the requirements of the design drawings. However, the outer circular surface formed by precision machining after turning is not It is completely ideal. After processing, the surface of the part will form a shallow surface layer. Its characteristics are very different from the characteristics of the internal base material. When precision hardware is processed, the surface is wedged during the entire cutting process. The complex stress state of fracture, extrusion and friction undergoes elastic and plastic deformation. Under the combined action of cutting force, cutting heat and surrounding media, the original geometric and physical properties of the surface of the part are changed. Therefore, the use of " "Surface quality" relies on the degree of complexion between the geometric, physical, chemical or other engineering performance status of the product surface layer and the technical requirements of the part. The main content expressed by it mainly includes the following aspects:

1. Surface roughness, the surface of precision metal processing has microscopic geometric characteristics formed by small pitch peaks and valleys, which are mainly caused by the motion trajectory of the cutting tool in precision machining. Its wave height and wavelength are generally straight. Will be greater than 1:50;

    2. The surface processing texture, the main direction of the surface microstructure, is mainly due to the precision machining method used in the surface formation, that is to say the relationship between the main movement and the feed movement;

    3. Surface waviness, the intermediate geometric shape error between the macro geometric shape error and the surface roughness, is mainly caused by the offset and vibration of the cutting tool. The wave height and wavelength are generally at 1:500. To 1:1000;

    4. The physical properties of the surface layer. In the process of precision mechanical parts processing, various complex physical and chemical changes occur on the surface of the parts, causing changes in the physical properties of the surface layer, which are mainly determined by three aspects. , Respectively, are the work hardening of the surface layer, the change of the radial structure of the surface layer and the residual stress of the surface layer;

    5. Scars, defects appearing in some individual positions on the surface of precision metal processing, most of which are randomly distributed, such as burrs, scratches and cracks;

 6. What are the effects of surface quality on the performance of parts? The surface quality actually reflects some geometric characteristics and the physical and mechanical characteristics of the surface layer, its wear resistance, fit quality, fatigue strength, corrosion resistance and contact for precision hardware processing Rigidity and many other aspects of performance will have an impact. The service life of precision hardware parts is largely determined by the wear resistance of the parts, the wear resistance of the parts and the friction material, the lubrication conditions of the working environment and the surface of the parts. Factors such as quality are all related. Under other stable conditions, the surface quality of parts plays a very important role in later use;

    The above is about the roughness control method of precision machined parts and its influence on later use.