Surface polishing determines the surface roughness, roundness and friction performance of silicon nitride balls. High-precision ceramic balls used in aerospace and medical fields need ultra-mirror polishing treatment. Professional polishing technology is the key to manufacture high-quality silicon nitride balls.
The polishing process is divided into rough grinding, fine grinding and ultra-fine polishing. After sintering, the blank ball has rough surface and tiny pores. Rough grinding removes surface burrs and uneven layers to preliminarily shape the sphere and ensure basic roundness.
Fine grinding adopts high-hardness diamond abrasive paste. Under constant pressure and rotating speed, the surface microscopic protrusions are evenly removed. After fine grinding, the surface roughness is reduced to below 0.05μm, meeting the requirements of industrial ordinary precision balls.
Ultra-fine mirror polishing is used for G5 grade high-precision products. Nano-level diamond abrasive is matched with soft polishing disc to carry out low-pressure slow grinding. The surface roughness can reach 0.003μm without grinding traces, achieving mirror smooth effect.
Cleaning and dust-free detection are essential after polishing. Residual abrasive particles on the surface are cleaned by ultrasonic pure water cleaning. Dust-free workshop detection ensures no tiny impurities remain on the ball surface, avoiding abrasive wear in later bearing operation.
Advanced polishing technology improves the surface finish of silicon nitride balls, reduces friction resistance and extends service life. Polishing level is an important standard to distinguish high-quality and inferior silicon nitride balls.
