摘要
采用X射线衍射仪、差热分析仪和热膨胀仪等手段研究了由氧化物粉末 (MgO、Al2 O3 和SiO2 )制备堇青石陶瓷时 ,添加Bi2 O3 对堇青石陶瓷相变和性能的影响 ,分析了Bi2 O3 在烧结过程中的作用机理是低温产生液相促进烧结。试验表明 ,Bi2 O3 能明显降低烧结温度 ,在 12 5 0℃烧成 3h后的陶瓷是由α堇青石和少量的 μ堇青石组成。随着Bi2 O3 含量增加 ,陶瓷的致密度和热膨胀系数逐渐升高。Bi2 O3 的添加量 (质量分数 )为 0 .0 4 ,原料相石英消失。Bi-O膨胀系数较Si-O的大和Bi3 + 离子进入堇青石晶格中是引起堇青石陶瓷热膨胀系数升高的主要原因。
Bi_2O_3 is used as an additive in the sintering of corderite ceramic to obtain ceramics with highly amounts of cordierite and to decrease the sintering temperature.In the present work,the cordierite ceramics were prepared with powder sintering method.The effects of Bi_2O_3 on the transformation and properties of cordierite ceramics were studied using X-ray diffractometer,differential thermal analysis and thermal dilatometer.The mechanism of Bi_2O_3 in sintering is liquid sintering.The results show that Bi_2O_3 obviously decreases the sintering temperature.When sintered at 1250℃ for 3h,the main crystallization phases of the ceramics are α-cordierite and μ-cordierite(small).The density and thermal expansion coefficient increase with increasing Bi_2O_3 content.The optimum content of Bi_2O_3 (mass fraction) is 0.04.Because the thermal expansion coefficient of Bi-O bond is much larger than that of Si-O bond,the addition of Bi_2O_3 cause the increase of the thermal expansion coefficient of the cordierite ceramics.
出处
《中国陶瓷工业》
CAS
北大核心
2003年第2期32-35,共4页
China Ceramic Industry
