Abstract: The need for higher propulsive and thermal efficiency in high temperature equipment has induced the search for materials that can withstand such harsh operating conditions. Within this group, the Nb-Si alloy system offers an attractive set of properties although they still present a challenge regarding the effects of oxygen. To address the role of processing environment on microstructure and oxidation performance of a Nb-Si multilayer, a powder mixture (Nb37wt%Si) were deposited under an argon atmosphere and in air. NbSi2 and Nb5Si3 were identified in multilayers processed with Nb37wt%Si mixture. The argon atmosphere accounts for changes in phase morphology and also for the enhanced oxidation resistance. This behavior can be accounted for by the high solubility of oxygen on silicides, that contributes to entrap oxygen in multilayers processed in air compromising oxidation performance.
Authors: Eloisa Pereira Cardozo and Ana Sofia C.M. D’Oliveira
Keywords: Additive Manufacturing, Nb silicides, Plasma transferred arc