Content area
Full Text
Multiprincipal-element alloys are an enabling class of materials owing to their impressive mechanical and oxidation-resistant properties, especially in extreme environments1,2. Here we develop a new oxide-dispersion-strengthened NiC°Cr-based alloy using a model-driven alloy design approach and laser-based additive manufacturing. This oxide-dispersion-strengthened alloy, called GRX-810, uses laser powder bed fusion to disperse nanoscale Y2O3 particles throughout the microstructure without the use ofresource-intensive processing steps such as mechanical or in situ alloying3,4. We show the successful incorporation and dispersion of nanoscale oxides throughout the GRX-810 build volume via high-resolution characterization of its microstructure. The mechanical results of GRX-810 show a twofold improvement in strength, over 1,000-fold better creep performance and twofold improvement in oxidation resistance compared with the traditional polycrystalline wrought Ni-based alloys used extensively in additive manufacturing at 1,093 °C5,6. The success ofthis alloy highlights how model-driven alloy designs can provide superior compositions using far fewer resources compared with the 'trial-and-error' methods of the past. These results showcase how future alloy development that leverages dispersion strengthening combined with additive manufacturing processing can accelerate the discovery of revolutionary materials.
High-entropy alloys, also commonly referred to as multi-principal element alloys (MPEAs), are a class of materials that are currently of interest among the metallurgical community1,2,7-9. In the past decade numerous scientific investigations have uncovered remarkable properties exhibited by these alloys710-13. One of the most heavily investigated MPEA family is the Cantor alloy C°CrFeMnNi and its derivatives2,8,14. This group of alloys showed excellent strain hardening, resulting in high tensile strength and ductility7,15-18. Overcoming the strength-ductility trade-off is a result of atomic-scale deformation mechanisms16, such as locally variable stacking-fault energies19 and magnetically driven phase transformations20. This class of alloys has also proven to be robust, resisting hydrogen environment embrittlement21, exhibiting improved irradiation properties22 and providing superior strength at cryogenic temperatures23. As a result, these alloys show great potential for numerous aerospace and energy applications in elevated-temperature and corrosive environments, allowing for weight reduction and higher performance operation.
One Cantor alloy derivative of special interest is the medium-entropy alloy NiC°Cr. This alloy family provides the highest strength at room temperature among the Cantor alloy and its derivatives2,24. Recently, this alloy was shown to provide impressive tensile properties (1,100 MPa room temperature yield strength) when undergoing partial recrystallization heat...