Additive Manufacturing of Refractory Metallic Materials: Additive Manufacturing of Nb-based Alloys and Re
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee
Program Organizers: Antonio Ramirez, Ohio State University; Jeffrey Sowards, NASA Marshall Space Flight Center; Omar Mireles, NASA; Eric Lass, University of Tennessee-Knoxville; Faramarz Zarandi, RTX Corporation; Matthew Osborne, Global Advanced Metals; Joao Oliveira, Faculdade Ciencias Tecnologias
Thursday 8:30 AM
March 23, 2023
Room: 24A
Location: SDCC
Session Chair: Faramarz Zarandi, Raytheon Technologies; Eric A. Lass, University of Tennessee-Knoxville
8:30 AM Invited
Design of Silicide Strengthened Nb Alloys for Additive Manufacturing: Alice Perrin1; Ying Yang1; Ryan DeHoff1; Michael Kirka1; 1Oak Ridge National Laboratory
Three refractory metal intermetallic composite (RMIC) alloys have been designed using CALPHAD modelling with the primary goals of promoting the Nb+Nb5Si3 eutectic reaction, increasing oxidation resistance, and decreasing the solidification temperature range. The Nb5Si3 phase was targeted because silicide precipitates increase specific strength and stiffness of alloys. A smaller solidification temperature range reduces hot cracking tendencies in additive manufactured alloys. These Nb-Si-Cr and Ni-Si-Cr-Mo alloys were cast and then surface processed with laser welding at different speeds to simulate additive manufacturing. The bulk cast alloys as well as the weld tracks were characterized through SEM, TEM, and hardness testing to determine if the phases predicted from modelling were accurate, and to quantify the effects of the size and phase fraction of each phase on the mechanical properties.
9:00 AM
Additive Manufacturing of Refractory Coatings for Ultra-high Temperature Applications: A Study on the Effect of Substate Dilution: Ashlee Gabourel1; Poulomi Mukherjee1; Nicholas Ury2; Samad Firdosy2; Douglas Hofman2; Atieh Moridi1; 1Cornell University; 2NASA Jet Propulsion Lab, California Institute of Technology
With the advancement of high temperature applications in the aerospace and energy sectors, the development of ultra-high temperature materials is a necessity to overcome the physical limitations of the current materials in use. Refractory metal carbides possess excellent mechanical properties at high temperatures, but result in cracking when manufactured using both conventional and additive routes. We explore the use of Direct Energy Deposition for in-situ alloying of Tungsten Carbide with Niobium on a Titanium substrate to 1) suppress solidification cracking by optimizing the concentration of Niobium 2) study the effect of substrate dilution on the microstructure and mechanical properties of WC-Nb system. Results show that, dilution of titanium forms a compositionally graded microstructure with WC-Nb. As distance from the substrate increases, the microstructure transitions to WC-Nb lamellar structures surrounded by Nb-rich regions and demonstrates a Vickers Hardness comparable to that obtained by the rule of mixture.
9:20 AM
Direct Energy Deposition of Nb-containing Refractory Alloys: Solidification Behavior, Microstructural Evolution, and Mechanical Properties: Saket Thapliyal1; Julio Rojas1; Patxi Fernandez-Zelaia1; Christopher Ledford1; Andres Rossy1; Michael Kirka1; Paul Brackman1; Michael Gao2; David Alman2; 1Oak Ridge National Laboratory; 2National Energy Technology Laboratory
Fusion-based additive manufacturing (F-BAM) processes have vastly augmented the component design space for the manufacture of geometrically complex components for high efficiency turbine engines. However, the compositional space that leads to alloys with good microstructural stability and good F-BAM printability still needs exploration. To this end, we assess the printability of the refractory alloy C103 (Nb-10Hf-1Ti) with direct energy deposition (DED) F-BAM process. The effect of DED processing conditions on the segregation and solidification behavior, microstructural evolution, and mechanical behavior has also been reported. The DED-processed components exhibited a crack-free columnar-grained microstructure with relative density of >99%. The implications of rapid solidification during DED on the nucleation and growth of brittle phases that form during conventional processing of C103 alloy have been discussed. Additionally, we outline the alloy design considerations that may lead to enhanced microstructural hierarchy and heterogeneity, and thus improved mechanical performance in F-BAM processed Nb-containing refractory alloys.
9:40 AM
Laser Powder Bed Fusion Process Development for Re: Joseph Sims1; Stephen Cooke1; Ryan Anderson1; Melissa Forton1; Madelyne Rushing1; 1Quadrus Advanced Manufacturing
Quadrus Advanced Manufacturing (QAM) is executing a Direct-to-Phase-II Small Business Innovation Research (SBIR) contract to develop the laser powder bed fusion (L-PBF) process for elemental Rhenium. Once that process is fully developed, the effort will pivot to execute a thorough material property characterization. This presentation will provide a status of the L-PBF process development and will also show the as-built microstructure of the refractory element. Lessons learned will also be shared.
10:00 AM Break
10:20 AM
Laser Powder Bed Fusion of Niobium and Exploration of Gradient Composites by Local Addition of Nanoparticles: Emre Tekoglu1; Alexander O'Brien1; Zachery Kutschke1; Bethany Lettiere1; John Hart1; Ju Li1; 1Massachusetts Institute of Technology
Additive manufacturing (AM) can overcome the challenges associated with conventional casting of refractory metals (e.g., niobium, tantalum, or tungsten).In particular, laser powder bed fusion (LPBF) of refractory materials has gained significant attention, yet it remains challenging to optimize LPBF parameters to prevent cracking.First, we present a baseline study of the key parameters that establish crack-free, high-density (>99.9%) LPBF of pure Nb.Pure Nb samples are produced using a commercial LPBF system (EOS M290). Importantly, we find that scanning each layer twice with the same toolpath is important to full densification and crack-free microstructures.Building upon this result, we present a preliminary study of gradient composites whereby nanoparticles–Si, Ti, and Al–are deposited locally onto the powder prior to LPBF.We study the influence of the nanoparticles on the microstructure, hardness, and oxidation resistance of the alloys, and discuss a pathway to incorporate this gradient capability into full-scale components.
10:40 AM
Melt Pool Geometry and Defect Susceptibility in Laser Powder Bed Fusion of Single Phase Refractory Alloys: Kaitlyn Mullin1; Carolina Frey1; James Lamb1; Chris Torbet1; McLean Echlin1; Tresa Pollock1; 1University of California Santa Barbara
Refractory alloys remain difficult to fabricate by laser-based additive manufacturing (AM) techniques due to their high melting temperatures, brittle nature, and high interstitial solubility. Many practical features dictating the processing-microstructure-property relationships of AM refractory alloys remain unknown, including printing strategies to minimize defects and solidification cracking susceptibility in single phase refractory alloys. To investigate the printability of this alloy class, a selection of single phase refractory substrates, including niobium-based alloy C103 and multi-principal element refractory alloys, are exposed to single laser tracks across a wide range of energy inputs. Changes in melt pool geometry, solidification morphology, and crack susceptibility with respect to composition and energy inputs are identified. The implications for suitable compositions and processing strategies for AM of refractory alloys will be discussed.