Powder bed fusion additive manufacturing of Ni-based superalloys: a review of the main microstructural constituents and characterization techniques

Abstract Metal additive manufacturing (AM) has unlocked unique opportunities for making complex Ni-based superalloy parts with reduced material waste, development costs, and production lead times. Considering the available AM methods, powder bed fusion (PBF) processes, using either laser or electron beams as high energy sources, have potential to print geometries a level of microstructural control. PBF is highly suited next generation components defense, aerospace, automotive industries. A better understanding as-built microstructure evolution during superalloys important both industry academia because its impacts on mechanical, corrosion, other technological properties, and, it determines post-processing heat treatment requirements. The primary focus this review outline individual phase formations morphologies in superalloys, their correlation printing parameters. Given hierarchal nature microstructures formed PBF, detailed descriptions each constituent are required enable commonly include γ, γ′, γ′′, $$\delta$$ δ , TCP, carbides, nitrides, oxides, borides, dependent composition. thorough characterization these phases remains challenging due multi-scale hierarchy alongside experimental challenges related imaging secondary that often nanoscale (semi)-coherent. Hence, discussion advanced techniques second review, more complete printed PBF. This an expressed goal directing research community toward tools necessary investigation processing-microstructure-property relationships engineering.