Preparation And Study Of Glass Ceramic Bond For CBN Gringding Tools

cBN abrasive and cBN grinding tool development and preparation of glass-ceramics weremade a detailed overview in this article. In according with the requirements of cBN grindingwheel, fluoride silicate glass used as the object of study, CaF2used as nucleating agent,analytical grade raw materials was used in experiments, fluoride-rich calcium alkali silicaglass was prepared by sintering, the composition，structure and property of glass-ceramic hasbeen investigated by XRD, SEM.The results show that: after crystallization at720℃for2h, canansite and frankamenitehad grown based on CaF2crystal. The bending stength achieved maximum with an addition of11%H3BO3under850℃. The bending stength was94.13Mpa.Crystal was random orientation，interlocking lath and crystal size was less2.5μm, the glass-ceramics has high bending strengthand fracture toughness attributed to crystal anisotropy, the KICwas0.4386MPa m1/2.Glass-ceramics by sintering, it had a great influence on glass-ceramic for heat treatmentsystem. For the research system,liquid phase sintering temperature is850℃for2h andcrystallization temperature is750℃for2h as the most appropriate heat treatmentsystem.Glass-ceramic obtained with the crystal anisotropy, the glass achieved a high bendingstrength and hardness and fracture toughness.Boron oxide formed by the reaction at above800℃,when cBN met oxygen in the air.Alayer of oxide filem formed on the surface of cubic boron nitride. It can prevent the furtheroxidation of cubic boron nitride. When the temperature is above1100℃,oxygen in the airwill be further erosion of cubic boron nitride with the volatile oxide,last cBN to destroy.Temperature should not exceed900℃for cBN abrasive sintered in dry air. The lower thesintering temperature more conducive to the protection against loss of abrasives, therebyenhancing the grinding efficiency.Use11%H3BO3content of cBN abrasive glass for a combination of direct agents, foundthat its expansion coefficient, poor wetting, strength is not higher. By adding low meltingborosilicate glass binder on the particle,it can increase the wettability and improve thebonding strength..