颗粒级配对发泡法-凝胶注模制备Al_2O_3多孔陶瓷性能的影响

Application of particle size distribution in preparation of porous Al_2O_3 ceramics by foaming-gel-casting

为了降低Al2O3多孔陶瓷制备过程中的干燥后收缩和烧后收缩,提高成品率,将d50分别为25.1、9.4和1.1μm的粗、中、细Al2O3粉体按粗粉中粉细粉质量比分别为50 40 10、10 40 50和100%全细粉的级配方式制备Al2O3泡沫浆料,研究颗粒级配对浆料黏度、干燥生坯的线收缩、烧后试样的线收缩、烧后试样的热导率等性能的影响。结果表明:颗粒级配可以有效提高固含量,且颗粒级配后的发泡浆料在静置30 min后仍能保持稳定,颗粒级配可以明显降低生坯的干燥线收缩以及烧后线收缩,并能降低热导率,提高了发泡法-凝胶注模工艺制备氧化铝多孔陶瓷的成品率。

Al2 O3 foam slurries were prepared according to 50 40 10 and 10 40 50 of mass ratio of coarse powder （d50 =25.1 μm）medium powder （d50 =9.4 μm）fine powder （d50 =1.1 μm）,and 100%fine pow-ders,respectively,in order to reduce drying shrinkage and sintering shrinkage and enhance the rate of final products of porous Al2 O3 ceramics.Effects of particle size distribution on slurry viscosity,linear shrinkage of dried green bodies,linear shrinkage and thermal conductivity of sintered bodies were researched.The re-sults show that adjusting particle size distribution can increase the solid content effectively,keep the foam slurries stable within 30 min,significantly lower the linear shrinkage of the dried green bodies and sintered bodies and thermal conductivity,and increase the rate of final products of porous Al2 O3 ceramics.