TY - JOUR
T1 - Excellent mechanical properties and thermal stability in a Zr gettering treated (VNb)80(TaTi)20 refractory multi-principal element alloy
AU - Han, Qing
AU - Dong, Yaguang
AU - Zhang, Qiuhong
AU - Zhou, Xiaoyang
AU - Wang, Cunyong
AU - Sun, Shihai
AU - Jin, Ke
AU - Xue, Yunfei
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2025/7
Y1 - 2025/7
N2 - Refractory multi-principal element alloys (RMPEAs) have garnered attention due to their high strength at elevated temperatures. However, their insufficient uniform elongation and thermal stability hinder their practical application. In this work, a single-phase BCC-structured (VNb)80(TaTi)20 RMPEA is designed based on the considerations of mixing enthalpy and Labusch solid solution strengthening model, which exhibits a tensile strength over 900 MPa and uniform elongation of ∼19 %. Unfortunately, the alloys containing high-concentration interstitial impurities (e.g. 300 wppm O, HO-alloy) suffer from severe embrittlement during long-term thermal aging, mainly due to the formation of Ti-(C/N/O) precipitates. By applying the Zr-foil gettering treatment, the concentration of interstitial impurities can be reduced below 100 ppm (LO-alloy), which greatly enhances thermal stability. The LO-alloy can maintain the microstructural stability and mechanical properties under thermal aging at 900 and 1000 °C for at least 1000 h. In addition to the desired combination of strength and ductility at room temperature, the alloy holds a high specific tensile strength of 98.9 MPa cm3/g at 1000 °C, which further grants it strong application potential at elevated temperatures. During tensile deformation, twinning is observed at room temperature, which is believed to enhance both strength and ductility.
AB - Refractory multi-principal element alloys (RMPEAs) have garnered attention due to their high strength at elevated temperatures. However, their insufficient uniform elongation and thermal stability hinder their practical application. In this work, a single-phase BCC-structured (VNb)80(TaTi)20 RMPEA is designed based on the considerations of mixing enthalpy and Labusch solid solution strengthening model, which exhibits a tensile strength over 900 MPa and uniform elongation of ∼19 %. Unfortunately, the alloys containing high-concentration interstitial impurities (e.g. 300 wppm O, HO-alloy) suffer from severe embrittlement during long-term thermal aging, mainly due to the formation of Ti-(C/N/O) precipitates. By applying the Zr-foil gettering treatment, the concentration of interstitial impurities can be reduced below 100 ppm (LO-alloy), which greatly enhances thermal stability. The LO-alloy can maintain the microstructural stability and mechanical properties under thermal aging at 900 and 1000 °C for at least 1000 h. In addition to the desired combination of strength and ductility at room temperature, the alloy holds a high specific tensile strength of 98.9 MPa cm3/g at 1000 °C, which further grants it strong application potential at elevated temperatures. During tensile deformation, twinning is observed at room temperature, which is believed to enhance both strength and ductility.
KW - Interstitial impurities
KW - Mechanical properties
KW - Phase stability
KW - Refractory multi-principal element alloy (RMPEA)
UR - http://www.scopus.com/inward/record.url?scp=105002245171&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2025.148299
DO - 10.1016/j.msea.2025.148299
M3 - Article
AN - SCOPUS:105002245171
SN - 0921-5093
VL - 934
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
M1 - 148299
ER -