Effect of NbC inoculants on the elastic properties and microstructure of additively manufactured IN718

Abstract

In this study, the effects of NbC inoculants on the elastic properties and microstructure of laser blown powder-directed energy deposition (LBP-DED) IN718 are investigated. The addition of the NbC particles increased the volume fraction of MC-type carbides and decreased that of the Laves phase. It was found that the inoculant containing samples exhibited a marginally increased hardness and an enhanced Brass texture component {110} 〈211〉. The occurrence of this textural enhancement is theorised to be a result of the NbC restricting dendritic growth along specific directions during build. The addition of the inoculant therefore offers a method of achieving a degree of microstructural and textural control during additive manufacturing.