Preparation Of Silicon Aluminum Hybrid Bond And Its Application Research

In this paper, silicon aluminum hybrid polymer bond was prepared by sol-gelmethod, as the same time, its structure and properties were characterized. And in order toimprove the thermal property of diamonds, a mullite film was coated on the surface ofdiamonds by a sol-gel method. The main contents of this article contain two aspects asfollowing:PartⅠ: One silicon aluminum hybrid polymer that was suitable for the grindingwheels as the bond were prepared by sol-gel method with aluminum nitrate, aluminiumisopropoxide and tetraethoxysilane as starting materials and water that is obtained in ourlaboratory as solvent. The surface morphology, composition, structure and thermalperformance of the silicon aluminum hybrid polymers power and resultant products werecharacterized by SEM, FT-IR, XRD, DSC-TG, and the influences of the sintering systemon the hardness and bending strength of the grinding wheels which the synthesizedsilicon aluminum hybrid polymers was used into were researched. And when theperformance of the grinding wheels is best, the content of the bond、moulding pressureand the heat preservation temperature was decided, and compared to the performance ofmodified phenolic resin grinding wheel abrasive. It was indicated that the power of thesilicon aluminum hybrid polymers that was synthesized by sol-gel method is irregularflake, and the silicon aluminum hybrid polymers have good thermal stability. When thesilicon aluminum hybrid polymer was heat-treated in different temperatures, we can getthe bond that is suitable for the grinding wheels. After the dried gel of the siliconaluminum hybrid polymers was calcined at400oC for2h, the power of the siliconaluminum hybrid polymers was obtained, to manufacture the sample of the grindingwheels with the power of the silicon aluminum hybrid polymers, abrasive and filler, and the content of the bond was20%, and the moulding pressure was20MPa, then thesample of the grinding wheels is sintered in500oC, finally the bending strength of thesample of the grinding wheels that was obtained at this temperature achieved maximumvalue,namely67.83MPa, and corresponding to the hardness of the grinding wheels was76HRB. By comparing to the performance of modified phenolic resin grinding wheelabrasive, it was shown that the performance of the silicon aluminum polymer bondabrasive grinding is good.PartⅡ: With aluminum nitrate and aluminium isopropoxide as aluminum source,tetraethoxysilane as silicon source, water as solvent, silica aluminum hybrid polymer solwas prepared by sol-gel method, the structure of the silica aluminum sol was examinedby FT-IR, XRD, and the sol that was synthesized by sol-gel method was coated on thesurface of the diamonds, meanwhile the influence of the viscosity of the sol, the times ofcoating and the type of diamonds on the coating of diamonds was studied. And thesurface morphology of the coated diamonds was characterized by SEM. The oxidationresistance property of the coated diamonds was characterized by TG. It was shown that acontinuous mullite film could be formed on the surface of diamonds, and after thediamonds was coated by silica aluminum film, the property of the diamonds wasapparently improved. The weight of the coated diamonds stayed stable, and the oxidationresistance property of the coated diamonds was increased compared to the uncoated ones,even the oxidation resistant temperature of the coated diamond single crystal wasincreased by75oC compared to that of uncoated ones, and the coated diamond brokenwas increased by100oC.