Fabrication of Multi-Functional Ceramic Composites by Slurry Stacking Method

为实现陶瓷/金属混合粉末的精细堆积，研制了一种计算机控制的粉末喷雾堆积装置。采用该工艺和热等静压工艺，以乙醇为溶剂，将不同比例的金属和陶瓷粉末均匀混合在悬浮液中，并在计算机控制下连续喷雾到预热的基板上，成功地制备了从陶瓷到金属的连续微结构转变的功能梯度材料。然后对沉积的粉末压坯进行冷等静压、玻璃包覆和热等静压。显微组织观察表明，该工艺可以精确地控制各种成分的轮廓，最小控制尺寸为0.01 mm厚度。结果表明，采用该工艺制备的金属/陶瓷梯度功能材料具有较好的抗裂性和抗热震性。

A powder spray stacking apparatus with a computer-controlling system has been developed for fine stacking of mixed ceramic/metal powders. Functionally gradient materials with a continuous microstructural transition from ceramics to metals have been successfully fabricated using this process followed by hot-isostatic pressing.In the present process, metal and ceramic powders with different mixing ratios were mixed homogeneously in the suspension using ethanol as a solvent, and were sprayd onto a preheated substrate with continuously graded composition by the computer control. The deposited powder compacts were then cold-isostatically pressed, glass-encapsulated and hot-isostatically pressed. The microstructural observation showed that this process could precisely control the various composition profile with the minimum control size of 0.01mm in thickness. It has been shown that the metal/ceramic functionally gradient materials fabricated by the present process have larger fracture resistance and thermal shock resistance than the monolithic Zirconia ceramics.