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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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58 records · Page 4

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NASA NTRS1991

Creep Deformation of B2 Alumindes

The creep resistance and elevated temperature deformation mechanisms in CoAl, FeAl, and NiAl are reviewed. The stress and temperature dependencies of the steady state creep rate, the primary creep behavior, the dislocation substructure, and the response during transient tests are used as the main indicators of the deformation processes. In single phase intermetallics, the influence of grain size, stoichiometry, and solid solution hardening have been examined. In addition, the effect of adding dispersoids, precipitates, and other types of reinforcements to improve creep strength are compared.

Nathal, M. V.↗

NASA NTRSDate not supplied

Modified Rosenthal Solution for Prediction of In Situ Alloyed GRCop-42 Melt Pool

Literature suggests that the energy needed to in-situ alloy material via additive manufacturing is higher per unit volume than their pre-alloyed counterparts, often despite the in-situ formation of thermodynamically favorable phases. This work, via experiments on in-situ alloyed GRCop-42 (Cu-4 at% Cr-2 at% Nb), will explore the energy needs of an elemental powder blend during in-situ alloying via laser powder bed fusion (LPBF). Empirically derived models will explore the influence of elemental thermophysical properties, net energy of in-situ reactions, and powder characteristics on the resulting LPBF energy demands, weld pool size and shape, and porosity evolution. Additionally, the influence of energy input during printing on the in-situ reaction to form Cr2Nb will be explored. Evolution of Cr2Nb dispersoid and copper grain shape, size, and texture can be related to the temperature reached, cooling rate, and time-as-melt during in-situ alloying via LPBF.

David Scannapieco↗

NASA NTRSDate not supplied

Expansion of Additive Manufacturing Capabilities Into in Situ Alloying of Dispersion Strengthened, High Temperature Cu Alloys

New alloys and materials are potentially possible through additive manufacturing’s unique thermal history. Current literature explores the fabrication of eutectic and solid solution strengthened alloys through in-situ alloying, to take advantage of AM’s unique thermal history. The resulting lessons learned by in-situ alloying currently available materials will likely lead to the development of novel materials solely possible through in-situ alloying. This work will expand the application of in-situ alloying via additive manufacturing to NASA’s GRCop-42 (Cu-4at% Cr-2at% Nb), a high temperature copper alloy which has shown success in additively manufactured combustion chambers from pre-alloyed powders. GRCop-42 is unique to literature because a reaction to form the Cr2Nb dispersoids is required during the in-situ alloying. Both reaction completion rate and how input energy from the AM process influences the reaction progress will be evaluated. Ultimately, expansion of in-situ alloying capabilities provides further insight to develop novel materials using AM.

David Steven Scannapieco↗

NASA NTRS2026

A Dispersion-Strengthened Low-Density Niobium Alloy and Its Elevated Temperature Mechanical Performance

In response to the elevated-temperature and weight-reduction demands of modern aerospace applications, a novel oxide-dispersion-strengthened low-density niobium alloy (LDNb-ODS) was fabricated using laser powder bed fusion (L-PBF). To overcome powder procurement barriers, L-PBF feedstock was produced by blending commercial Nb521, Ti64, and Cr powder with Y2O3 nanoparticles via resonant acoustic mixing. Following L-PBF and a 1400°C vacuum heat treatment, the alloy achieved a density of 6.73 g/cc and a fine mean grain size of 4.62 µm stabilized by uniform ~30 nm yttria dispersoids. Microstructural analysis revealed a chemically inhomogeneous build with lack-of-fusion defects and a titanium (Ti) shift from a nominal 31.5 wt% in the starting powder blend to 24.8 wt% in the printed part due to preferential Ti loss during printing. Elevated-temperature tensile testing demonstrated that LDNb-ODS maintained a superior specific yield strength of 60-85 MPa/(g/cc) up to 800°C, outperforming nickel-based alloys Ni625, Ni230, and GRX-810. Between 870°C and 950°C, its specific strength surpassed both Ni718 and Ni625. In rapid stress-rupture testing at 1093°C and 20.7 MPa, uncoated LDNb-ODS survived 21.4 hours (a tenfold increase over legacy C-103) while an R512E silicide coating extended rupture life to 84.8 hours, confirming that oxidation accelerates low-stress failure. These findings demonstrate that additive manufacturing of LDNb-ODS provides a viable, lightweight alternative to nickel-based superalloys for high-temperature (>850°C) aerospace components.

Low Density Niobium Alloy↗