THE MICROSTRUTURE AND COMPRESSIVE PROPERTIES OF ARC–MELTED FeNb ALLOYS

The microstructures and compressive properties of arc-melted Fe_(100-x)Nb_x(x=6,9, 12,15,17) alloys,which are relevant to eutectic reaction(L→α-Fe+Fe_2Nb),were investigated by SEM,XRD and test machine system 810(TMS 810).The results showed that the microstructure of the ingot sample consisted of primary phase(α-Fe or Fe_2Nb) and sub-micro-sized eutectics.Fe_(91)Nb_9 alloy had the best comprehensive properties with ultimate strength about 1.63 GPa,yield strength about 1.04 GPa and compressive strain ductility about 23%.For alloy Fe_(91)Nb_9,the substitution of Hf element for Nb element produced no observable effects on both the microstructure and the compressive mechanical properties;while the substitution of Y element for Fe element resulted in obvious change in the microstructure and dramatic deterioration in the mechanical properties.