Oxygen-assisted spinodal structure achieves 1.5 GPa yield strength in a ductile refractory high-entropy alloy  

作　　者：Dingcong Cui Yuyu Zhang Linxiang Liu Yue Li Lei Wang Zhijun Wang Junjie Li Jincheng Wang Feng He 

机构地区：[1]State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China [2]Research&Development Institute of Northwestern Polytechnical University in Shenzhen,Shenzhen 518063,China

出　　处：《Journal of Materials Science & Technology》2023年第26期11-20,共10页材料科学技术（英文版）

基　　金：the financial support from the National Natural Science foundation of China(NSFC,Granted No.52001266);the Fundamental Research Funds for the Cen-tral Universities(No.G2022KY05109,No.G2022KY05113);Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012703);The Shanghai“Phosphor”Science Foundation,China(23YF1450900)。

摘　　要：Refractory high-entropy alloys(RHEAs)with room-temperature ductility are drawing growing attention for potential high-temperature applications.However,the most widely used metallurgical mechanisms appear weak in optimizing their strength and ductility.Here,we report that the nanoscale spinodal struc-ture in Ti_(41)V_(27)Hf_(15)Nb_(15)O_(2)leads to the highest tensile yield strength(∼1.5 GPa)among the existing RHEAs and good elongation of∼12%.With the aid of thermodynamic calculations,we show that oxygen plays a dominant role in controlling the formation of the spinodal structure by influencing the spinodal gap of the Ti-V-Hf-Nb system.Exploring the atomic structure of the spinodal structure(β+β^(∗)),we showed that the large lattice misfit of the spinodal phases is mainly responsible for the excellent strengthen-ing effect while the planar to wavy dislocation glide mode transition accounts for the retained ductility.This work provides a novel strategy to improve the mechanical properties of the RHEAs and deepens the understanding of their phase stabilities.

关 键 词：High entropy alloys Spinodal decomposition Strengthening mechanisms 

分 类 号：TG139[一般工业技术—材料科学与工程]