粒径对低温燃烧法合成掺硼堇青石粉性能的影响.doc

摘要:以硝酸镁、硝酸铝、硅酸为原料，尿素为燃料，用低温燃烧法简便快捷地合成堇青石前驱粉。在不同粒径的堇青石前驱粉中加入适量的粘结剂和添加剂于170MPa下干压成片,在不同温度下烧结，获得堇青石基玻璃陶瓷。

　　　根据阿基米德原理，用排水法测量烧结体的密度，研究不同燃料对低温燃烧合成堇青石粉烧结性能的影响；通过x-射线衍射分析样品的物相，研究不同粒径对堇青石析晶性能的影响。结果表明：

　　　（1）以Mg(NO3)2·6H2O, Al(NO3)3·9H2O和H2SiO3为原料，CO(NH2)2为燃料，加入2.5％B2O3可在1000℃获得单晶相的α-堇青石基玻璃陶瓷。

　　　（2）低温燃烧法制备堇青石基玻璃陶瓷的析晶过程为：非晶态 → μ-堇青石 → α-堇青石。高温有利于α-堇青石相析晶。

　　　（3）用低温燃烧法制备堇青石基玻璃陶瓷时，同等条件下，小粒径粉体更有利于α-堇青石晶相的获得，也有利于烧结。

　　　（4）添加剂（2.5％B2O3）能明显促进α-堇青石析晶。 

　　　（5）不同种晶体密度不同，混晶物密度与各晶相含量相关。

关键词：粒径；低温燃烧；堇青石；析晶；烧结

ABSTRACT:The MgO-Al2O3-H2SiO3( MAS ) glass powder have been synthesized by low-temperature combustion technique using magnesium nitrate, aluminium nitrate, silicic acid as material, urea as fuel. Put into right amount of binder and additives,   pigeonhole in flakes under 170Mpa, frit and obtain base glass ceramics of cordierite at different temperature. 

　　　According to Archimedes' principle, measuring and sritting the density of the body with the law of water drainage, studying different particle size to burning and formating cordierites powder to frit on the influence of performance at low temperature; analyzing the thing looks of the sample through x - ray diffraction, study the influence that the different fuels analyses brilliant performance to the cordierite. The result shows:

　　　(1) Cordierite-based glass-ceramics have been synthesized in 1000℃ combustion technique using magnesium nitrate, aluminium nitrate, silicic acid as material and urea as fuel, and 2.5% as additive.

　　　(2) Low-temperature combustion legal prepare cordierite base glass ceramics crystal process is from the amorphous to μ- cordierite to α- cordierite. High temperature is used toα- cordierite phase wafer chromatography.    

　　　(3) Prepared with low-temperature combustion legal cordierite base glass ceramics, under the same condition, small particle size powder more conducive to alpha pansy/green ShiJing phase gain, also be helpful for sintering.

　　　(4) Additives（2.5% B2O3） can promote the precipitation of α-cordierite phase.

　　　(5) Different kinds of crystal have different density, the density of mixed material is associated with the crystalline phase.

Key words: particle size；low-temperature combustion；cordierite；crystallization；sintering