无机溶胶陶瓷结合剂的制备与研究

摘要

Using silica sol,alumina sol and chemical pure H3BO3,NaNO3,LiNO3as raw materials,the sol-gel method was used to prepare Al2O3-B2O3-SiO2-R2O inorganic sol ceramic binder,and then based on the diamond,spraying drying method was used to prepare diamond-vitrified bond composite powders and then the bulk samples were ob-tained after pressing and sintering the powders.The phase compositions,microstructure, fracture morphology,bending strength of the inorganic sol ceramic binder and sintered samples were characterized by X-ray diffraction,TG-DSC,scanning electron microscopy and motorized bending tester.Results showed that the ceramic binder heated at 820℃ for 1 hour,the binder has uniform structure and can be melted into a liquid phase to better coating the diamond.With the increase of binder content,the bending strength of the dia-mond-vitrified increases,while the porosity decreases.When the binder content is 30wt%,the bending strength and porosity are 95.42MPa and 34.36%.%以硅溶胶、铝溶胶及化学纯 H3BO3、NaNO3、LiNO3为原料,以溶胶凝胶法制备 Al2O3-B2O3-SiO2-R2O 体系无机溶胶陶瓷结合剂,并以金刚石为磨料,采用喷雾干燥法制备金刚石-陶瓷复合粉体,后经干燥、压制、烧结制得金刚石-陶瓷复合烧结体.利用 X 射线衍射仪、TG-DSC、扫描电镜、抗折试验机等表征手段对无机溶胶陶瓷结合剂的物相组成、显微形貌、复合烧结体断面形貌及抗弯强度等进行分析.结果表明,820℃/1h下进行烧结,以此配方制备的无机溶胶陶瓷结合剂结构均匀,且可熔融为液相并对金刚石进行较好地包覆.随着陶瓷结合剂含量的增加,金刚石-陶瓷复合烧结体的抗弯强度随之提高,而气孔率随之降低,且当结合剂含量为30wt%时,抗弯强度和气孔率分别为95.42 MPa和34.36%.