Reply to 'Comment on 'Simple Mathematical Model for the Electrical Conductivity of Highly Porous Ceramics''

Autor: Soji Tsuchiya, Junichiro Mizusaki, Katsunori Waragai, Yuji Kuwayama, Hiroaki Tagawa, Yoshihide Arai
Rok vydání: 1996
Předmět:
Zdroj: Journal of the American Ceramic Society. 79:2999-2999
ISSN: 1551-2916
0002-7820
DOI: 10.1111/j.1151-2916.1996.tb08744.x
Popis: As mentioned in the comment, what the authors emphasized in the paper is the problem ``How does electric conductivity of porous ceramics change with the progress of sintering from an as-pressed green to a fully dense state?`` In actual sintering processes starting from green bodies, the relative density starts at about 0.5, at which the observed relative conductivity, {sigma}{sub c}/{sigma}{sub 0}, is close to zero. However, when the authors start the modeling by considering a dense ceramic with pores scattered in it, the material is continuous and the conduction path is available down to very low density, which certainly does not explain the observed facts. The authors considered it difficult to answer the problem from modeling starting from dense ceramics, particularly at the initial stage of sintering, and proposed a model which basically starts from a stack of spheres. The model emphasized in the comment considers a porous ceramic body as a mixture of gas phase and dense ceramic particles with different particle sizes, where the gas phase is assumed to be a cluster of particles. In fact, the authors had also considered this type of approach before they reached the model of one-dimensional strings of spheres. The problem ofmore » their discussion is now converted to ``How can one express the change in R with the progress of sintering?`` This may be an interesting problem worth considering. Anyway, the authors appreciate the comment very much, and they hope many ceramists will be interested in this very familiar and unsolved problem.« less
Databáze: OpenAIRE
Externí odkaz: