Evolution of the pore structure of a ceramic powder compact during sintering

Abstract

This paper presents a mathematical model for the sintering of a ceramic powder compact. It treats the green compact as a matrix of an initial pore-size distribution and takes into account the random structure of a green compact formed by the compaction of powders. Using two measurable pore structural properties, surface area and porosity, the effects of the initial pore parameters on the densification rate and the evolution of the pore volume distribution are studied by computer simulation. The results show that a green compact with low porosity and high surface area demonstrates fast densification rates for given sintering conditions. In terms of the initial pore-size distribution, a narrow distribution or a low exponent n in the Rosin-Rammler function results in fast pore elimination. In a practical system, a wide particle-size distribution with small mean size for a powder compact is desirable for fast densification.