Effect of Second Phase Dispersoids on Supersolidus Sintered Stainless Steels

摘要

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 was added to 316L and 434L stainless steel. The compacts were solid-state and supersolidus sintered at 1200 ℃ and 1400 ℃, 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 EPMA, the distribution of various elements in intergranular as well as intragranular regions was quantified for stainless steel with and without YAG additions. The density of stainless steel samples sintered through supersolidus route was higher than those of solid-state sintered samples. Up to 5-wt% YAG dispersed samples exhibited much better hardness when compared to the straight P/M stainless steel both in solid-state as well as supersolidus sintered conditions. The tribological properties of stainless steel-YAG composites were determined using a pin-on-disc wear tester. The YAG dispersed samples exhibited better wear resistance when compared to the straight P/M stainless steel.