Refractory metal-based multi-principal element alloys (MPEAs) are compelling materials for high-temperature (1000–2000 K)structural applications. However, only a minuscule fraction of their vast and heterogeneous com...Refractory metal-based multi-principal element alloys (MPEAs) are compelling materials for high-temperature (1000–2000 K)structural applications. However, only a minuscule fraction of their vast and heterogeneous compositional design space has beenexplored, leaving many potentially interesting alloys undiscovered. In this two-part work, a large region of the 11-element Al-Cr-Fe-Hf-Mo-Nb-Ta-Ti-V-W-Zr design space is computationally explored to identify refractory MPEAs with simultaneously high yieldstrength or specific yield strength and body-centered cubic (BCC) solid solution stability. In Part I, two case studies illuminate keyfactors and considerations in the yield strength versus phase stability tradeoff, provide guidelines for narrowing the expansivedesign space, and identify many candidates predicted to be stronger than refractory MPEAs reported to date, with BCC phasestability. Our findings indicate that medium entropy ternary alloys can outperform alloys with more elements and highlight theimportance of exploring regions away from the equiatomic center of composition space.展开更多
Here the discovery of refractory multi-principal element alloys(MPEAs)with high-temperature strength and stability is pursued within a constrained and application-relevant design space.A comprehensive approach is deve...Here the discovery of refractory multi-principal element alloys(MPEAs)with high-temperature strength and stability is pursued within a constrained and application-relevant design space.A comprehensive approach is developed and applied to explore all 165 ternary systems in the Al-Ce-Fe-Hf-Mo-Nb-Ta-Ti-V-W-Zr family.A subset of ternary systems that contain large areas in composition–temperature space with high strength and robust BCC phase stability is found.Twelve sets of high-performing alloys are identified,each set optimized for one combination of phase constraint,optimization target,and temperature range.Preliminary mechanical tests support the viability of the method.This work highlights the importance of considering phase stability,exploring non-equiatomic regions of composition space,and applying application-relevant constraints.Parts I and II provide three down-selection techniques for identifying high-performing BCC refractory MPEAs,design guidelines,and many candidates predicted to have BCC phase stability and strengths 2–3 times higher than any reported to date.展开更多
基金This work was performed under the auspices of the U.S.Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344was supported by the Laboratory Directed Research and Development(LDRD)program under project tracking code 22-SI-007.Document Release#LLNL-JRNL-839431.
文摘Refractory metal-based multi-principal element alloys (MPEAs) are compelling materials for high-temperature (1000–2000 K)structural applications. However, only a minuscule fraction of their vast and heterogeneous compositional design space has beenexplored, leaving many potentially interesting alloys undiscovered. In this two-part work, a large region of the 11-element Al-Cr-Fe-Hf-Mo-Nb-Ta-Ti-V-W-Zr design space is computationally explored to identify refractory MPEAs with simultaneously high yieldstrength or specific yield strength and body-centered cubic (BCC) solid solution stability. In Part I, two case studies illuminate keyfactors and considerations in the yield strength versus phase stability tradeoff, provide guidelines for narrowing the expansivedesign space, and identify many candidates predicted to be stronger than refractory MPEAs reported to date, with BCC phasestability. Our findings indicate that medium entropy ternary alloys can outperform alloys with more elements and highlight theimportance of exploring regions away from the equiatomic center of composition space.
基金This work was performed under the auspices of the U.S.Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344was supported by the Laboratory Directed Research and Development(LDRD)program under project tracking code 22-SI-007.Document Release#LLNL-JRNL-840231.
文摘Here the discovery of refractory multi-principal element alloys(MPEAs)with high-temperature strength and stability is pursued within a constrained and application-relevant design space.A comprehensive approach is developed and applied to explore all 165 ternary systems in the Al-Ce-Fe-Hf-Mo-Nb-Ta-Ti-V-W-Zr family.A subset of ternary systems that contain large areas in composition–temperature space with high strength and robust BCC phase stability is found.Twelve sets of high-performing alloys are identified,each set optimized for one combination of phase constraint,optimization target,and temperature range.Preliminary mechanical tests support the viability of the method.This work highlights the importance of considering phase stability,exploring non-equiatomic regions of composition space,and applying application-relevant constraints.Parts I and II provide three down-selection techniques for identifying high-performing BCC refractory MPEAs,design guidelines,and many candidates predicted to have BCC phase stability and strengths 2–3 times higher than any reported to date.
