含钛添加剂对堇青石陶瓷热膨胀性能的影响

Effects of Ti-bearing additives on thermal expansion of cordierite ceramics

以粘土、滑石、氧化铝微粉等为原料 ,于1370～ 14 0 0℃烧成 ,合成了堇青石陶瓷。研究了添加 5 %～ 2 0 %的钛酸铝 (AT )或 5 %～ 15 %的氧化铝(A)与氧化钛 (T)的混合物 (A与T的摩尔比 1∶1)对堇青石陶瓷的相组成及热膨胀率的影响。结果表明 :添加AT或A +T均能有效地降低材料的热膨胀率 ;XRD分析表明 ,在添加 15 %以上AT或添加10 %以上A +T的堇青石试样中形成了莫来石与钛酸铝晶体 ;SEM显微照片表明 ,引入AT或A +T均促进了堇青石的合成。从效果和节约能源考虑 ,应添加 10 %～ 15 %的A +T ,烧成温度为 14 0 0℃左右。

Cordierite ceramics were synthesized by firing green bodies at 1370～1400 ℃ using raw materials of clay,talc and alumina powders.Effects of 5%～20% aluminum titanate(AT) or 5%～15% mixture of alumina(A) and titania(T) (molar ratio 1∶1) on phase compositions and thermal expansion rates of the ceramics were researched.The dilatometric experiments showed that both AT and A+T can effectively decrease thermal expansion rate.XRD analysis results showed that mullite and aluminum titanate crystals were formed in samples containing more than 15% AT or those containing more than 10% A+T.SEM analysis indicated that either AT or A+T promotes the synthesis of cordierite and crystal growth.Adding 10%～15% A+T and sintering at temperature about 1400 ℃ should be the optimum condition for synthesizing cordierite ceramics.