Research Of Alumina Enhanced Polishing Abrasive Properties

Alumina plays an important role in precision machining manufacturing industry due to its advantage of high degree of hardness and fine stability properties.Along with the development of modern technology,in the production of resin polishing abrasive, fine grit sharpeners was applied in the different fields widely,especially in high precision grinding and mirror polishing processing,so superfine powder not only have good dispersion but also have good compatibility when it mixed with other material.Because of the high surface energy and easy reunion of the ultrafine powder(<10μm),the compatibility difference with resin bond can't be suited in the polishing wheel.So,the abrasive products have the problems of easy wearing off,polishing scratches, indentation and surface defect.Obviously,the key points are how to prepare the dispersed and compatible powder in order to enhance the application capacity of resinoid abrasive polishing abrasive.This paper study on surface modification of ultra-fine Al₂O₃ powder,assess its effect on friction resistance of polishing abrasive and analysis the friction and wear mechanism of polishing abrasive,the surface modification of ultra-fine Al₂O₃ with PAA was studied,compound particle was prepared by organic coating,the result show that the modified ultra-fine Al₂O₃ powder has improved wear resistance,nanometer SiO₂ was used to enhance epoxy resin and the process parameters was improved, it further enhances the polishing abrasive performance.Compound particle was prepared by organic coating,modification process route was analysed,the influence of reaction temperature,coating time and stirring rate to the particle diameter and spheroidicity degree was researched,and the optimal craft condition of polymer modification was ascertained.Analyzing the influence of category and dosage of dispersant to the particle's dispersion effect.The best reaction conditions were 30min,70℃,500rpm,PAA12% and CMC9%.The performance of compound particle such as spheroidicity degree,particle size distribution and wettability etc,which showed that not only could the dispersibility and fluidity be improved,but the compatibility difference be improved. Characterized by means of laser particle size analyzer,X-ray diffraction,infrared spectrum analyzer and scanning electron microscope,the surface properties of ultra-fine Al₂O₃ particle by organic coating change greatly,but its structure is normal,because the modified ultra-fine Al₂O₃ powder has improved adhesion to the bond,it can avoid threshing phenomenon,reduce scratches and enhance its wearability.the result show that the best conditions were 80℃,Al₂O₃ 30%,SiC 20%.Using nano SiO₂ modified epoxy resin was researched,the result show that grafted and bonding was produced between nanoparticles and organic polymer when nano SiO₂ particles scattered fully in the resin material,it strengthened material toughness,strength,wear resistance and ductility;the influence of guring temperature,dispersing time of particles in the resin and dosage etc was analysed, the optimal craft condition was ascertained,it was that curing temperature 60℃,dispersing time 60min and SiO₂ 3%.