QUANTITATIVE ASSESSMENT OF ENHANCED SINTERING CONCEPTS

The theories of enhanced sintering identify three criteria for a sintering enhancer; high solubility of base material in the second phase, segregation of the additive at the interparticle boundaries, and easy diffusion of the base material through the segregated phase. Although these qualitative ideas are valuable in the selection of a sintering enhancer, a quantitative assessment would render them more meaningful. This study proposes a figure of merit relating to thermodynamic quantities, capable of identifying a sintering enhancer reliably. This figure of merit is defined as a weighted sum of solubility, segregation, and diffusion terms. It is a dimensionless quantity, and can easily be calculated from phase diagram features. The proposed figure of merit has been used successfully to identify effective sintering enhancers for iron, and the results have been compared with sintered density values obtained from a controlled experiment and from the literature. PM/0493. © 1990 Maney Publishing.