Flowability of NbC-based cermets for additive manufacturing via L-PBF

Abstract

Niobium-based refractory alloys have attracted attention in several industrial areas, such as metalworking, steelmaking, military, and armoring applications, among others. The production of these refractory alloys using additive manufacturing techniques, specifically selective laser fusion in a powder bed (L-PBF), has been a major challenge; this is primarily due to the complex optimization of the sintering process parameters required to obtain dense parts, free of porosity or cracks, and to achieve highly homogeneous layers in the powder bed. However, the success of L-PBF is highly dependent on the physical properties of the powders used in the process. Key factors such as good flowability, reduced particle size and narrow distribution, sphericity, and density influence powder spreading, powder layer uniformity, and the final part integrity. Furthermore, properties of the composite, such as hardness, toughness, and wear resistance, can be modified by changing the cermet composition, which could also negatively impact its flowability. This work aims to evaluate the physical properties of NbC-based cermets with different compositions to better understand their influence on metallic powder flowability. Optimizing powder properties and flowability through processing parameters is crucial for L-PBF to fully harness the potential of NbC-based cermets, thereby paving the way for their broader adoption in high-performance applications.