粒径对掺杂硼磷铋堇青石粉性能的影响_化学系.rar

摘要:本实验以水合硝酸镁、水合硝酸铝和硅酸为原料，尿素为燃料，硝酸铵为燃烧助剂，用低温燃烧法简便快捷地合成了堇青石前驱粉(MgO-Al2O3-SiO2)。在不同粒径的堇青石前驱粉中加入适量的粘结剂和复合添加剂(2.5%B2O3+5%Bi2O3 +2.5%P2O5)，把粉体在170MPa下干压成片, 于不同温度下烧结获得堇青石基玻璃陶瓷。

　　　用排水法测量烧结体的密度，研究粒径对掺杂硼磷铋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，研究粒径对掺杂硼磷铋堇青石粉析晶性能的影响。实验结果如下：

　　　（1）以Mg(NO3)2·6H2O, Al(NO3)3·9H2O和H2SiO3为原料，CO(NH2)2为燃料，可用低温燃烧法制备堇青石基玻璃陶瓷。

　　　（2）本实验制备堇青石基玻璃陶瓷的析晶过程为：非晶态→μ-堇青石相→α-堇青石相。

　　　（3）复合添加剂(2.5% B2O3+ 2.5%P2O5 + 5% Bi2O3)明显促进μ-堇青石向α-堇青石的相转变或促进α-堇青石相直接析晶。

　　　（4）加入复合添加剂(2.5% B2O3+ 2.5%P2O5 + 5% Bi2O3)在950℃左右即可获得较高纯度的α-堇青石。

　　　（5）小粒径粉体有助于α-堇青石相低温析晶，也有助于堇青石的低温烧结。

关键词：粒径；添加剂；低温燃烧；堇青石；性能

Abstract:The MgO-Al2O3-SiO2( MAS ) glass powder have been synthesized by low-temperature combustion technique using magnesium nitrate, aluminium nitrate, silicic acid as material, sucrose or 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. 

　　　Measuring and sritting the density of the body with the law of water drainage, studying particle size to burning and formating cordierites powder contains right amount of additive BPBi 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 particle size analyses brilliant performance to the cordierite contains right amount of additive BPBi. Experimental results are as follows:

　　　(1) Cordierite-based glass-ceramics have been synthesized by low-temperature combustion technique using magnesium nitrate, aluminium nitrate, silicic acid as material and urea as fuel.

　　　(2) the brilliant process of a little brilliant glass of cordierite is a non- brilliant attitude →μ-cordierite →α-cordierite; 

　　　(3) compound additives(2.5%B2O3+2.5%P2O5+5%Bi2O3) can obviously promote the transformation from μ-cordierite to α–cordierite or promote the transformation from glass to α – cordierite directly.

　　　(4) adding compound additive(2.5%B2O3+2.5%P2O5+5%Bi2O3) can obtain high purity α-cordierite ceramics at 950℃. 

　　　(5) Small size powder help α-cordierite crystallization, also conduce to the cordierite sintering in a low-temperature.

Key words: size; additives; low-temperature combustion; cordierite; performance