Advancing Additive Manufacturing of Ni-Based Superalloys: Integrating High Entropy Alloy Thermodynamics into Novel CoNi-Based Superalloys for Powder Based Technologies

Abstract

A new class of CoNi-based high entropy superalloy (CoNi-HESA) was developed for laser powder bed fusion (L-PBF) additive manufacturing, integrating high entropy alloy (HEA) thermodynamics. The alloy (Co-35Ni-8Al-4Ti-4V-2W-2Ta-9Cr) was methodically crafted using gas atomization. Employing L-PBF, a comprehensive Design of Experiment (DoE) approach studied the impact of processing parameters (laser power and scan speed), establishing a process window for >99.9% relative density. Advanced electron microscopy revealed a single-phase fcc solid solution, confirming thermodynamic predictions. In parallel, the CoNi-HESA, designed for demanding applications in energy, space, and nuclear sectors, showcased impressive tensile strength (>1GPa), ductility (≈30%), and sustained yield strength up to 800°C. The alloy's crack-resistant properties make it ideal for L-PBF, revolutionizing high strength and temperature component production. CALPHAD calculations based on the HEA database validated the alloy design strategies. This study converges HESA synthesis, L-PBF optimization, and alloy performance, offering a paradigm shift in advanced manufacturing.