A novel CoNi-based high entropy superalloy has been developed for fusion-based additive manufacturing processes based on configurational entropy and high entropy alloy principles. A multi-component compound with the chemical composition of Co-35Ni-8Al-4Ti-4V-2W-2Ta-9Cr was prepared via gas atomization. A comprehensive study was conducted to establish a process-structure relationship in laser powder bed fusion processed CoNi superalloy powder. The effect of processing parameters, including laser power and scan speed, on part characteristics was studied using the Design of Experiment approach based on the response surface methodology. Numerical models validated by experimentation were used to develop a process window to attain parts with a relative density of >99.9%. Advanced electron microscopy incorporated with phase analysis was used to observe grain structure and defects (i.e., pores, microcracks) and phase evolution. It was concluded that thermodynamic predictions were in good agreement with microstructure analysis to attain a single-phase fcc solid solution in the powder and as-built coupons.
