Research On Semi-fixed Abrasive Tool Based On Solid Phase Reaction And Sapphire Polishing

This paper presents a new approach based on solid-phase reaction of semi-fixed soft abrasive tool machining technology in order to solve problems such as surface scratches, crack, sub-surface damage and low removal rate during the lapping and polishing process of sapphire substrate. An efficient semi-fixed abrasive tool has been developed, and key production technology has been studied, its mechanical properties and performance have also been carried out. Finally, machining performance of semi-fixed abrasive tool has been tested by polishing sapphire. The main work of this thesis includes the following aspects:The machining mechanism of semi-fixed abrasive tool based on solid-phase reaction has been researched. The conditions and influencing factors in sapphire wafer solid-phase reactions has been analyzed. According to the chemical thermodynamic principles, HSC Chemistry software has been used to simulation verification the possibility of solid-phase reactions between SiO2, CeO2 abrasive and sapphire wafer.The fabrication process and quality influence factors of semi-fixed abrasive tool have been researched. According to technical index of semi-fixed abrasive tool, raw material including two kinds of different abrasive(SiO2 and CeO2), bonding, porogen and others materials to make abrasive tool have been selected. Hardness of abrasive tool has been set as objective function, the regression method is used to design abrasive tool formula. Analyze mixing raw materials, fixing molding, drying, hardening and surface dressing of semi-fixed abrasive tool, then manufacture semi-fixed abrasive tool. Production process and quality influence factors of semi-fixed abrasive tool have been analyzed.The properties of semi-fixed abrasive tool such as hardness, compressive property and microstructure also have been tested. In this thesis, the DOE was used to analyze the effects of different abrasives on the surface quality and material removal rate by sapphire polishing of semi-fixed abrasive tool. By using semi-fixed abrasive tool made of SiO2 and bonding, the material removal rate is 1.32μm/h after polishing sapphire, the surface roughness Ra of sapphire is changed from 22 nm to 6nm in 6 hours.In a word, the semi-fixed abrasive tool which based on solid phase reaction and used for sapphire polishing, has the characteristics of high efficiency and low damage.