Fabrication of Multi-Functional Ceramic Composites by Slurry Stacking Method

研制了一种微机控制的粉末喷雾堆垛装置，用于陶瓷/金属混合粉末的精细堆垛。从陶瓷到金属的连续微观结构转变的功能梯度材料已经成功地利用热等静压工艺制备。在本工艺中，以乙醇为溶剂，将不同混合比例的金属粉末和陶瓷粉末在悬浮液中均匀混合，并通过计算机控制将其喷涂到具有连续分级成分的预热基板上。然后对沉积的粉末压块进行冷等静压、玻璃封装和热等静压。显微组织观察表明，该工艺可以精确控制各种成分轮廓，最小控制尺寸为0.01mm厚度。实验结果表明，该方法制备的金属/陶瓷梯度功能材料比单片氧化锆陶瓷具有更大的抗断裂性和抗热震性。

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.