Challenges and insights from laser powder bed fusion and cold spray processing of Nb-Ta based complex concentrated alloys

Abstract

Advanced materials with load-bearing capabilities in extremely high-temperature environments are in growing demand and has intensified interest in developing and manufacturing new refractory complex concentrated alloy components. Despite recent advances in designing tailored alloys, significant hurdles in their production and processing continue to hinder their practical use. This study focuses on creating model non-equiatomic Nb-Ta-based refractory complex concentrated alloys as potential candidates aiming at enhanced high-temperature stability and performance in space propulsion applications. Spherical pre-alloyed powders were produced using gas atomization. Laser powder bed fusion and cold spray were employed to investigate the manufacturing challenges associated with this new alloy. The findings emphasize how the characteristics of the powder impact its processability with laser powder bed fusion and cold spray. Issues such as high interstitial content, uneven microstructures, fractured and hollow particles, and microsegregation led to material embrittlement. For cold spray, the wide range of particle sizes in the feedstock negatively impacted the material deposition. The results offer valuable insights and recommendations for enhancing the design, preparation, and production of refractory alloys for additive manufacturing