Fabrication and characterization of microwave sintered PM Fe-Cr-Y2O3 composite

Abstract

This research is focused on assessing the feasibility of the innovative microwave sintering technology for fabricating iron – chromium composites via powder metallurgy route. The microwave sintered composites were compared with their conventionally sintered counterparts in terms of physical and mechanical properties (micro Vickers hardness and compressive strength). Microwave sintering is proved feasible to consolidate the composite. The result also revealed that the microwave sintered iron chromium composites possess improved density, micro hardness and compressive strength compared to the conventionally sintered composites. Process evaluation also revealed that microwave assisted sintering can lead to reduction of 70% of sintering time when compared to conventional sintering. Another aims of this research is to study the effect adding varying weight fraction of yttria reinforcement to the iron chromium composites. For this purpose iron-chromium composites is reinforced with 5, 10, 15 and 20 wt.% of the ceramic particulates. From the study it is observed that the mechanical properties of microwave sintered iron – chromium composites improved with the addition of 5 wt.% ceramic content. For the conventional sintered composites, highest micro hardness and compressive strength were obtained from the 10 wt.% reinforced composites.The highest hardness value is given by microwave sintered composite. Other physical properties such as density was decreased as the reinforcement content increased. This is due to the increasing presence of porosity in the composites. However, microwave sintered composites exhibit better density relative to theoretical density and densification behaviour.