Study On The Structure And Properties Of Vitrified Bond With Ultra-high Speed Grinding Of CBN Wheel

Ultra-high speed grinding is first put forward by western scholars, and it’sbecame a revolutionary of materials processing technology gradually after years ofdevelopment, its outstanding characteristic is can greatly improve the grindingefficiency of the abrasive and grinding ratio; reduces the grinding force and specificabrasion energy; can significantly improve the processing quality and accuracy;suitable for grinding hard materials. At present, China has a large gap compared withdeveloped countries in the world on this technology, it’s mainly displayed in the weakof basic theory research and practical application. Therefore, it’s has great practicalsignificance to study of ultra-high speed grinding of CBN wheel. This paper mainlystudies the structure and performance of vitrified bond what suitable for ultra-highspeed grinding of CBN wheel.The experiments added different amount of ZrO₂, La₂O₃, BaO, Y₂O₃and CeO₂asadmixture on the Na₂O-B₂O₃-Al₂O₃-SiO₂multivariate basal glass system, thendifferent composition of vitrified bonds is prepared. We studied its content ofadditives on performance and microstructure of the vitrified bonds through to themechanical property （bending strength, microhardness, impact toughness and abrasionratio）, thermal property（differential thermal, thermal expansion coefficient andliquidity）, and observation means such as metallographic images, XRD and SEM. Atthe same time, the experiments preparation of the different components of vitrifiedbonds CBN grinding tools, then studied the effects of additives on the properties ofCBN grinding tools by means of mechanical properties of grinding tools underdifferent sintering temperature. Finally, we determine the vitrified bond CBN grindingwheel which suitable for high speed grinding through to the comparison with thecomprehensive performance of all the vitrified bonds and CBN grinding tools.The results show that the defined amount of several kinds of additive havesignificant improvement action to the mechanical properties of the vitrified bonds, and the vitrified bond with4%ZrO₂has the more outstanding comprehensiveperformance. The bending strength of vitrified bond is78.58MPa, microhardness is833.01MPa, impact toughness is4.54KJ·m^-2, abrasion ratio is1:4.56, the maximumthermal expansion coefficient is8.60×10^-6℃^-1, and the vitrified bond has a higherconnection of the internal network, dense microstructure, higher content glass phase atthis time. Furthermore, the CBN grinding tool which sintering at770℃use thisvitrified bond also has excellent mechanical properties, the bending strength is74.79MPa, impact toughness is4.14KJ·m^-2, and the abrasion ratio is1:82.32, the grindingspeed reached163m/s at this time, and can be used in ultra-high speed grinding..