复合添加剂抑制钛酸铝热分解的作用及其机理的研究

Study on the Function and Mechanism of Compound Additives Suppressing the Thermal Decomposition of Aluminum Titanate

本文采用Ｘ衍射分析、热膨胀分析、透射电镜和电子探针分析详细研究了复合添加剂抑制钛酸铝热分解的作用和机理。研究表明，复合添加剂抑制钛酸铝热分解的效果比单一添加剂的效果更为显著。复合添加剂不仅提高了钛酸铝的热稳定性，而且还保持了其优良的低膨胀特性。复合添加剂抑制钛酸铝热分解的机理是：一方面，复合添加剂能生成与钛酸铝晶体结构相同的化合物与之发生类质同象的取代固溶；另一方面，氧化铁能活化晶格起着矿化剂的作用，促使复合添加的离子更多地固溶到钛酸铝晶格中去，从而大大提高钛酸铝的稳定性。

The function and mechanism of compound additives suppressing the thermal decomposition of β-Al2TiO5 has been investigated in detail by means of X diffraction analysis, dilatometry, TEM and EPMA. It has been indicated that compound additives are more effective than single additives in regard to suppressing the thermal decomposition of β-Al2TiO5. Compound additives not only improve the thermal stability of β-Al2TiO5, but also preserve its excellent property of low expansion. The mechanism of compound additives suppressing the thermal decomposition of β-Al2TiO5 is that on the one hand, Compound additives can form the compounds which not only have the same crystal structure as β-Al2TiO5, but also can form complete substitutional solid solutions with β-Al2TiO5. On the other hand, ferric oxide can activate crystal lattice and enable other canons in compound additives to have more solubility. Consequently, the stability of β-Al2TiO5 has been greatly improved.