Al_2TiO_5粒径对Al_2TiO_5-ZrO_2复合材料性能的影响

Effect of Al_2TiO_5 particle size on Al_2TiO_5-ZrO_2 composite properties

分别将平均粒径为2、6、10μm的Al2TiO5粉分散在Zr4+浓度为0.06mol.L-1的氧氯化锆溶液中,滴加0.2mol.L-1的氨水至溶液的pH值为9.1～9.3,使ZrO2沉淀于Al2TiO5颗粒表面,过滤,干燥,于650℃焙烧,制成ZrO2质量分数为5%的Al2TiO5-ZrO2复合粉体,然后以PVA为结合剂成型为53mm×10mm×10mm的试样,经干燥和1500℃保温2h烧成后,检测烧后试样的显气孔率、常温抗折强度、热膨胀率、抗热震性并观察其显微结构。结果表明,用平均粒径为6μm的Al2TiO5粉制备的Al2TiO5-ZrO2复合材料的综合性能最好:显气孔率最低(5%),抗折强度最大(35MPa),热膨胀率最小,抗热震性最好,结构较致密。

The Al2TiO5 composite powder with 5% ZrO2 was prepared by dispersing Al2TiO5 powder （average particle size was 2,6,10 pm,respectively） in zirconium oxychloride solution （Zr^4＋ concentration was 0. 06mol·L^-1）, adding 0.2 mol·L^-1ammonia by drop until the pH of solution reached 9.1 -9.3 ,making ZrO2 precipitated on the surface of Al2TiO5 particles, filtering, drying, and firing at 650 ℃ The specimens with the size of 53 mm ×10 mm ×10 mm were prepared with PVA as binder,dried,and fired at 1 500 ℃ for 2, h. The apparent porosity, cold modulus of rupture, thermal expansion rate and thermal shock resistance of fired specimens were determined,and microstructure was analyzed. The results showed that the Al2TiO5 -ZrO2 composite prepared with 6μm Al2TiO5 powder had the best comprehensive properties： the lowest apparent porosity（5% ）,the highest modulus of rupture （35 MPa）,the lowest thermal expansion rate,the best thermal shock resistance and the dense structure.