Study On Process For The Preparation Of Aluminum Titanate Superfine Powder With Zero Decomposition Ratio

The main purpose of the study is to prepare aluminum titanate (Al2TiO5/AT) fine powder with good thermal stability. Improving the thermal stability of aluminum titanate synthesized by using single MgO additive is emphasized.The influence of preparing conditions on aluminum titanate composing was inquired. By analyzing element content of alumina and titania source, arranging a stoichiometric dosage, and keeping the chemical homogeneity from sol to mixed Ti-Al oxide precursor, a high activity powder was prepared. After calcining the precursor powder at 1250℃ for 2h, aluminum titanate phase is formed . The forming temperature is 50℃ lower than the reported value.By using single MgO additive, fine Al2(1-x)MgxTi1+xO5 (AMT) solid solution powders were synthesized. Three products with different x values (x=0.04,0.07,0.135) were prepared. Their stability is higher than pure aluminum titanate. Moreover, after 1100℃ decomposition experiment they still keep aluminum titanate as the main crystalline phase, and their crystal lattice constants a, b, c almost linear increase with the increasing x value. The Al1.86Mgo.o7Ti1.07O5 (x=0.07) one, which has a middle lattice constant c value, has zero decomposition ratio, its thermal stability is superior. According to us, it is the first time that aluminum titanate with zero decomposition ratio was compounded by using single MgO additive. The result means that there is a suitable adding ratio of MgO and the content can effectively stabilize aluminum titanate, correspondingly, there exists a suitable crystal lattice constant c, which is slightly bigger than the standard parameter of aluminum titanate. It is shown that the conclusion of the bigger c value related to more stable AT is worth reconsidering.The research also found that AMT with distinguish thermal stability was synthesized whenadopting the dosage of Al2(1-x)MgxTi1+xO5. Based on the result, it may be reasonable to consider the method of adding extra MgO to stabilize ready-made AT power as a lower effective one.The value of these new discovers lies in that they supply a new considering basis for developing synthesizing technology of AT with concurrent high thermal stability and strength and for researching thermal stability mechanism of AT.