不同添加剂对钛酸铝热膨胀系数影响的研究

钛酸铝是一种优异的高熔点、低膨胀无机非金属材料．为提高其强度、抑制其热分解，往往在钛酸铝中引入添加剂．本文研究了单一添加剂和复合添加剂对钛酸铝膨胀系数的影响．结果表明：引入少量的稀土元素氧化物能显著降低钛酸铝的热膨胀系数．引入1～4mol％CeO₂或2mol％La₂O₃可使钛酸铝的膨胀系数降至接近于零．这就为开发零膨胀材料提供了新的方法．在钛酸铝中引入1～4mol％Fe₂O₃，其膨胀系数保持不变．在含有4mol％Fe₂O₃的钛酸铝中再引入SiO₂，钛酸铝的膨胀系数增大，而加入另一种稀土元素氧化物则能降低其膨胀系数．三种添加剂的适当配比能将钛酸铝的膨胀系数调整至最小．这对于引入复合添加剂对钛酸铝的改性是很有意义的．

Effect of Different Additives on the Thermal Expansion Coefficient of Aluminium Titanate

Aluminium titanate is an excellent inorganic non-metal material due to its high melting point and low expansion. In order to improve its strength and to suppress its thermal decomposition, additives are frequently introduced into it. In this paper, the effect of a single additive or compound additives on the thermal expansion coefficient of Al2TiO5 was investigated. The results show that the addition of some rare-earth oxide can greatly reduce the thermal expansion coefficient of Al2TiO5. For example, the addition of 1~4mol% CeO2 or 2mol% La2O3 makes its expansion coefficient come near zero. That gives a new approach in the development of materialswith no thermal expansion. It I s indicated that there is no change in the expansion coefficient of Al2TiO5 by adding 1~4mol% Fe2O3 in it. The addition of SiO2 in Al2TiO5 containing 4mol% Fe2O3 increases its expansion coefficient while the addition of another rare-earth oxide decreases the expansion coefficient. Proper batching of three additives can adjust the expansion coefficient of Al2TiO5 to minimum. The addition of the compound additives may be very significant for improving the properties of Al2TiO5.