Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Fabrication of Nb-Si-Al components by Additive Manufacturing Techniques
Submission Author:
Eloisa Cardozo , PR
Co-Authors:
Eloisa Cardozo, Ana Sofia D'Oliveira
Presenter: Eloisa Cardozo
doi://10.26678/ABCM.COBEM2023.COB2023-1584
Abstract
Nb based alloys are considered the most appropriate to meet extreme environmental requirements replacing Nickel superalloys when they no longer respond accordingly.. Although the fabrication of Niobium alloys is challenging, Additive Manufacturing processing techniques allow to process advanced materials by in-situ synthesis of Nb alloys simultaneously with the construction of the component. Laser Powder Bed Fusion (LPBF) is a widely used, associated with a high geometry resolution and the high thermal gradients that account for a fine microstructure. LPBF contrast with Arc-DED additive techniques that offer a larger productivity and coarser microstructures due to the lower thermal gradients imposed during the deposition of each layer. Little is known about the processing of Niobium alloys by additive techniques, as well as the properties of these additive parts. This investigation takes an important step to process sound Niobium alloys containing high hardness low toughness silicide compounds as multilayers, taking advantage of the in-situ synthesis of alloys during the processing of multilayers. The LPBF “in-situ” synthesis of the Nb47Si10Al powder mixture, was compromised by the fast solification rate indicating that low thermal gradients are required to successfully induce in-situ synthesis of Nb silicides. To achieve lower thermal gradients, the Plasma Transferred Arc Directed Energy Deposition (PTA-DED) process was successfully chosen to obtain in-situ synthesis of Nb-based alloys during the deposition of an elemental powder mixture. Multilayers were processed and the impact of multiple thermal cycles in the microstructure of the Nb silicide walls was discussed.
Keywords
Additive manufacturing, Laser powder bed fusion, Plasma Transferred Arc, Niobium alloys, Refractory materials
