Study On Glass Ceramic Bond Used In Grinding Wheel Based On Sol-Gel In-situ Method

This paper prepared Li₂O-ZnO-Al2O3-SiO₂ system glass-ceramics bond and the multicomponent sol by sol-gel method, and discusses the ZnO, nucleation agent ZrO₂ and P₂O₅ and crystallization temperature on the system of microcrystalline glass binder shrinkage rate, crystallization behavior, microstructure, bending strength and the influence of the thermal expansion coefficient, etc. and to meet the conditions of the in-situ gel forming process required, obtain sol and glass-ceramics as well as more reasonable technological process and process parameters, etc. Get the following results:The addition of electrolytes that affect the stability of the order of SiO₂ sol is ZrOCl2·8H₂O>（NH₄）₂HPO₄>Zn（NO3）2·6H₂O. When the pH value is 1.5, the viscosity of the sol and the multicomponent gel time respectively minimum and maximum is 150min and 18mPa.s, the minimum particle size of the sol is 327.0nm. When the solid content of sol is keeping around 50-55wt%, the gel time is adjusted between 40-60min. When the temperature is 90℃, the turbidity and viscosity of the sol reached the maximum 156NTU and 15.2mPa.s, the shortest initial gel time is 20min, when the temperature is keeping around 70-80℃, initial gel time of the sol is about 40-60min. DMF as drying control chemical additives can solve cracking of gel during the drying process, Determine the optimal experiment of DMF dosage of 10vol%.The addition of ZnO, nucleation agent ZrO₂ and P₂O₅ in the microcrystalline glass had a greater influence on the performance of bond, when the amount of ZnO is 10 mol%, the shrinkage rate of bond is the largest, the largest bending strength reached the maximum value of 86 MPa; when the content of ZrO:is 4mol%, and the crystallization process of 900℃/2h. binder precipitation Li₂ZnSiO₄ and m-ZrO₂ crystal phase, the number of crystal is more, and grain size is smaller, the maximum bending strength is 104MPa, the minimum thermal expansion coefficient is 11.3x10^-6/℃; When P₂O₅ content is 3mol%, precipitation in small expansion coefficient β-spodumene solid-solution and β-quartz solid phase, the bending strength of binder reached a maximum of 98MPa. the minimum thermal expansion coefficient is 6.7×10^-6/℃. Although add 4mol%ZrO₂ binder of bending strength is higher, considering the match degree in thermal expansion coefficient between binder and abrasive, finally select add 3mol%P₂O₅ binder as optimal formula.Diamond and microcrystalline glass bond composite body prepared by sol-gel in-situ method, after 600℃/1h and 900℃/2h crystallization process, microstructure analysis, bond of diamond coated rate close to 100%, the combination of diamond abrasive and bond strength is higher, and diamond surface covered with microcrystals after heat treatment, it will greatly enhance the strength of the ceramic bonded diamond grinding wheel.