Solving oxygen embrittlement of refractory high-entropy alloy via grain boundary engineering

被引：184

作者：

Wang, Zhengqi ^{[1
]}

Wu, Honghui ^{[1
,2
]}

Wu, Yuan ^{[1
]}

Huang, Hailong ^{[1
]}

Zhu, Xiangyu ^{[3
]}

Zhang, Yingjie ^{[1
]}

Zhu, Huihui ^{[1
]}

Yuan, Xiaoyuan ^{[1
]}

Chen, Qiang ^{[1
]}

Wang, Shudao ^{[1
]}

Liu, Xiongjun ^{[1
]}

Wang, Hui ^{[1
]}

Jiang, Suihe ^{[1
]}

Kim, Moon J. ^{[3
]}

Lu, Zhaoping ^{[1
]}

机构：

[1] Univ Sci & Technol Beijing, State Key Lab Adv Met & Mat, Beijing Adv Innovat Ctr Mat Genome Engn, Beijing 100083, Peoples R China

[2] Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA

[3] Univ Texas Dallas, Dept Mat Sci & Engn, Richardson, TX 75080 USA

来源：

MATERIALS TODAY | 2022年 / 54卷

基金：

中国国家自然科学基金;

关键词：

Refractory high-entropy alloy; Grain boundary engineering; Mechanical properties; Ductilization; INTERMETALLIC COMPOUND; NONMETALLIC IMPURITIES; ELECTRON LOCALIZATION; BORON; SEGREGATION; DUCTILITY; STRENGTH; SIGMA-5; REFINEMENT; STABILITY;

D O I：

10.1016/j.mattod.2022.02.006

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Refractory high-entropy alloys (RHEAs), particularly NbMoTaW RHEAs, exhibit outstanding softening resistance and thermal stability at ultra-high temperatures, but suffer from room-temperature brittleness, which severely limits their processability and thus practical application. In this study, we successfully achieved large plasticity of >10%, along with high strength of >1750 MPa in the NbMoTaW RHEAs via grain boundary engineering with the addition of either metalloid B or C. It was revealed that the room-temperature brittleness of the as-cast NbMoTaW RHEA originates from the grain-boundary segregation of the oxygen contaminant which weakens grain-boundary cohesion. The doped small-sized metalloids preferentially replace oxygen at grain boundaries and promote stronger electronic interaction with the host metals, which effectively alleviates the grain boundary brittleness and changes the fracture morphology from intergranular fracture to transgranular fracture. Our findings not only shed light on the understanding of the embrittlement mechanism of RHEAs in general, but also offer a useful route for ductilization of brittle HEAs.

引用

页码：83 / 89

页数：7

共 48 条

[1] IMPROVEMENT IN ROOM-TEMPERATURE DUCTILITY OF THE L12 TYPE INTERMETALLIC COMPOUND NI3A1 BY BORON ADDITION [J].