Attributes of Spark Plasma Sintering on Developing Oxide Dispersion Strengthened Ferritic Steels and Understanding Structure–Property Relation

Abstract

Ferritic alloys strengthened by oxide dispersoids having a composition of Fe–16Cr–2W–0.3Ti–0.5Y2O3 and Fe–16Cr–2W–0.3Ti–0.75Y2O3 were developed through mechanical alloying followed by spark plasma sintering process. The densification behaviour of ferritic steel was understood while sintering at a temperature of 900 °C with soaking for 5 min, at the applied pressure of 50 MPa. X-ray diffraction analysis was done on milled powders and sintered bulk samples to confirm the alloying and crystallographic changes. Field emission scanning electron microscopy (FESEM) was carried out to study the morphology and FESEM-EDS to ascertain the composition of alloyed powders. Transmission electron microscopy study conceded the evolution of nanocrystalline ferritic steel during MA. Distinctive stages of mechanical alloying were observed. System with 0.5 Y2O3 displayed better densification behaviour and possessed higher mechanical properties.