【摘要】 选用两种粒径大小不同的氧化铝粉体,通过选择分散工艺配制了适合离心成型的流变性好的浆料。用此浆料以离心成型工艺成功制备了具有气孔梯度的材料,并对材料的微观形貌、气孔率以及孔径分布进行了分析。结果表明:引入分散剂后pH值为9～10时,粉体的zeta电位绝对值最大,此时浆料流变性能最好。用此浆料制得的陶瓷样品经过1400℃烧制后具有梯度分布的粒径和气孔,样品底部气孔率为29.2%,气孔尺寸在0.2～1.0μm左右;顶部气孔率只有18.6%,而气孔尺寸则小于0.2μm。更多还原

【Abstract】 A suspension with good rheology and suitable for centrifugal casting was prepared from two Al2O3 powders with different particle sizes by choosing the appropriate process. Porosity gradients Al2O3 ceramics were fabricated by centrifugally casting the sus- pension, and the microstructure, porosity and pore size distribution were analyzed. The results indicate that the powder shows the maximum absolute value of zeta potential when dispersive agents are added and the pH value is 9—10, and the suspension has the best rheology. Using this suspension to cast ceramics sample and fired at 1 400 ℃, the particles and pores of the sample have gradient distribution. The porosity and pore size at the bottom of the sample are 29.2% and about 0.2—1.0 μm respectively, while the corre- sponding values at the top of the sample are just 18.6% and less than 0.2 μm respectively.更多还原