TY - JOUR
T1 - Origin of age softening in the refractory high-entropy alloys
AU - Liu, Junliang
AU - Li, Bo-Shiuan
AU - Gardner, Hazel
AU - Gong, Yilun
AU - Liu, Fengxian
AU - He, Guanze
AU - Moorehead, Michael
AU - Parkin, Calvin
AU - Couet, Adrien
AU - Wilkinson, Angus J.
AU - Armstrong, David E. J.
PY - 2023/12/8
Y1 - 2023/12/8
N2 - Refractory high-entropy alloys (RHEAs) are emerging materials with potential for use under extreme conditions. As a newly developed material system, a comprehensive understanding of their long-term stability under potential service temperatures remains to be established. This study examined a titanium-vanadium-niobium-tantalum alloy, a promising RHEA known for its superior high-temperature strength and room-temperature ductility. Using a combination of advanced analytical microscopies, Calculation of Phase Diagrams (CALPHAD) software, and nanoindentation, we investigated the evolution of its microstructure and mechanical properties upon aging at 700°C. Trace interstitials such as oxygen and nitrogen, initially contributing to solid solution strengthening, promote phase segregation during thermal aging. As a result of the depletion of solute interstitials within the metal matrix, a progressive softening is observed in the alloy as a function of aging time. This study, therefore, underscores the need for a better control of impurities in future development and application of RHEAs.
AB - Refractory high-entropy alloys (RHEAs) are emerging materials with potential for use under extreme conditions. As a newly developed material system, a comprehensive understanding of their long-term stability under potential service temperatures remains to be established. This study examined a titanium-vanadium-niobium-tantalum alloy, a promising RHEA known for its superior high-temperature strength and room-temperature ductility. Using a combination of advanced analytical microscopies, Calculation of Phase Diagrams (CALPHAD) software, and nanoindentation, we investigated the evolution of its microstructure and mechanical properties upon aging at 700°C. Trace interstitials such as oxygen and nitrogen, initially contributing to solid solution strengthening, promote phase segregation during thermal aging. As a result of the depletion of solute interstitials within the metal matrix, a progressive softening is observed in the alloy as a function of aging time. This study, therefore, underscores the need for a better control of impurities in future development and application of RHEAs.
UR - http://www.scopus.com/inward/record.url?scp=85179642104&partnerID=8YFLogxK
U2 - 10.1126/sciadv.adj1511
DO - 10.1126/sciadv.adj1511
M3 - Article
SN - 2375-2548
VL - 9
JO - Science advances
JF - Science advances
IS - 49
ER -