Effect of YAG addition on sintering of P/M 316L and 434L stainless steels

The present study examines the sintering behavior and effect of yttria alumina garnet (YAG) addition on ferritic (434L) and austenitic (316L) stainless steel during solid-state and supersolidus liquid-phase sintering (SLPS). Up to 10 wt.% YAG (Al5Y3O12, AlYO3) was added to 316L and 434L stainless steel. The compacts were solid-state- and supersolidus-sintered at 1200 and 1400 degreesC, respectively. The sintered samples were characterized for their density and hardness. The effect of sintering and YAG addition on the microstructural evolution in supersolidus-sintered samples is compared with that obtained by solid-state sintering. Through electron probe microanalysis (EPMA), the distribution of various elements in intergranular as well as intragranular regions was quantified for stainless steel with and without YAG addition. The density of stainless steel samples sintered through the supersolidus route was higher than that of solid-state-sintered samples. Up to 5 wt.% YAG dispersed samples exhibited much better hardness when compared to the straight powder metallurgy (P/M) stainless steel both in solid-state- as well as supersolidus-sintered conditions. (C) 2004 Elsevier B.V. All rights reserved.