Study on Evaluation Method of Hierarchy in Ceramics Manufacturing Processes

Abstract

Fine ceramics manufacturing process is constituted of several processes such as material crushing, preparing, mixing, powder compacting and sintering process. These processes have each peculiar size of basic particle which causes each material behaviors and determine the material properties. In order to elucidate these material behaviors and properties thermophysically, the thermophysical three concepts of particle system, entropy and free energy have to be defined. But before defining these three concepts, we have to know the size of basic particle of each process. Because these thermophysical three concepts can be defined only by obtaining the information of basic particle size. Up to now, the size estimation method of basic particle has not yet been developed. From this point of view, in this paper, the size estimation method of basic particle especially in powder compacting and sintering processes is noticed and discussed thermophysically. As a result of it, a new size estimation method of basic particle in each process is presented by use of the thermophysical concepts of entropy and free energy, and the method is applied to powder compacting and sintering processes by use of three ceramics powder of BaTiO3, PZT and Mn-Ni-CuO powder. And the validity of this method is checked experimentally, obtaining interesting knowledges on the hierarchy problems of fine ceramics manufacturing process.