Preparation And Study Of Glass Ceramic Bond For CBN Gringding Tools By Mixed Sintering

Glass ceramic vitrified bond is good for CBN grinding tool because of its good wear resistance, high strength and excellent high temperature resistant performance. Glass-ceramic can be prepared by the parent glass via controlling the behavior of crystallization. At present,it is the general technique of preparing glass-ceramics. Adding the ceramic material of micron-size or nanoscale to the bond, and then promoting the interface reaction and wettability by controlling the firing temperature. This is the key of the research.In this paper,mixed sintering method was studied.It is used for CBN grinding tool.The problem of Li2O-Al₂O₃-SiO2 glass ceramic vitrified bond and vitrified bond were studied.Besides,The problem of mixing sintering and sintering processes were also researched in my research.This paper researched reaction mechanism of crystallization and mixed sintering,using both methods to prepare glass-ceramics.By the method of ceramic pyrometric cone, We investigate refractoriness of bond. The phases of the sintered samples are analyzed by using X-ray diffraction. The flexural strength of the samples was tested using three-point bending method.Grain and size of the sintered samples are observed with scanning electron microscope.Experimental results show that : 1. Glass material 1 has optimal comprehensive performance. It’s refractoriness is 600℃. It’s breaking strength is 43.5MPa. It’s the basis of the experiment. It makes no influence to its crystallization behavior. 2. Li2 O can lower the crystal temperature and vitrified bond’s refractoriness. what’s more,Li2 O also can promote the separation of spodumene. When the mass fraction of Li2 O is 7%, the bond has the best mechanical properties. Theflexural strength is 78 MPa. 3. Glass material 1 and spodumene glass-ceramic bond were sinreted using mixed sintering method. The refractoriness of vitrified bond was decreased with increasing thecontent of spodumene glass-ceramic bond additives. When the mass fraction of, spodumene glass-ceramic bond was 60%, the flexural strength is 72 MPa. When the mass fraction of it was 80%, the flexural strength is 74 MPa. 4.Glass material 1 and Al₂O₃ were sinreted using mixed sintering method. The introduction of Al₂O₃ inclined to increase the bond’s refractoriness and reduce its fluidity. In the process of sintering,Al₂O₃ and NaAl SiO4 were produced. Mixed sintering method can divide into two categories: sintering process and melting method. The benefit of melting method is that it canhelp improving the interface bonding of the minicrystal and glass phase.As for the melting method, the flexural strength increased first and then decreases. It is found that when the content of Al₂O₃ is 8%, the flexuralstrength reaches its maximum value. As for the sintering process, the strength of the matrixsdecrease along with the increase of Al₂O₃.