Temperature‐Gradient‐Driven Diffusion in Rapid‐Rate Sintering

Abstract

The vacancy diffusion flux, driven by the neck growth curvature (1 /ρ) which contributes to conventional sintering of a powder compact, is theoretically compared with that arising from thermal diffusion, driven by the temperature gradient (grad T/T) during the final stage of sintering. Under conditions experienced in ultrarapid sintering, the thermally driven vacancy flux can exceed the curvature‐driven flux by a factor of 1000. This effect may explain the phenomenon of enhanced densification rates observed in plasma sintering.