Experimental assessment of modified statistical theory of sintering

Abstract

Several experiments have been conducted to measure the parameters of microstructural evolution, i.e. pore size, grain size, total length per unit volume of pore, and pore-size distribution. The modified statistical theory of sintering has been employed to evaluate these parameters. The comparisons of experimental and theoretical data are in good agreement, which further justifies the modified statistical theory of sintering. The evaluated activation energy is 1461 kJ mol−1 suggesting that Ti4+ might be the most probable rate-limiting species in the later stages of sintering of high-purity barium titanate. The morphological parameter,x, which could predict pore shrinkage whenx 1 has further been verified. Surface diffusion might play a role in pore growth and in reducing the total length per unit volume of pore at the beginning of the intermediate stage of sintering. A morphological path for sintering based on the calculated values of microstructural evolution has been proposed, which has been successfully used to sinter high-purity barium titanate to relative density > 99.4% ρt with a fine-grain size of 1.2 μm.