Grain size effect on the temperature-dependence of elastic modulus of nanocrystalline NiTi

Chu，Kangjie1; Wang，Bing2; Li，Qiao3; Onuki，Yusuke4; Ren，Fuzeng1

2023-02-10

10.1016/j.jallcom.2022.167907

JOURNAL OF ALLOYS AND COMPOUNDS   Impact Factor & Quartile

0925-8388

The effect of grain size on temperature-dependent elastic modulus (TDEM) of polycrystalline NiTi over a temperature span of 200 °C was investigated by dynamic thermomechanical analysis (DMA). It is found that the TDEM rapidly reduced with grain size down to nanoscale. In-situ neutron diffraction and molecular dynamics (MD) simulation reveal that the volume fraction and thermal stability of austenite phase at low temperature gradually increased with the reduction of grain size due to the mechanical constraint of grain boundary, which results in the two-phase coexistence during cooling. The compensation of the intrinsic opposite TDEM of austenite and martensite leads to the overall reduced TDEM in nanocrystalline NiTi. This study strongly implies that the TDEM of shape memory alloy can be tailored by grain size.

Elastic modulus Grain size effect Molecular dynamics simulation Neutron diffraction Shape memory alloys

English

First ; Corresponding

National Natural Science Foundation of China[52122102];

MATERIALS SCIENCE

2-s2.0-85141451794

Scopus

1.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
2.Key Laboratory of Testing for Manufacturing Process,Ministry of Education,School of Manufacturing Science and Engineering,Southwest University of Science and Technology,Mianyang,Sichuan,621010,China
3.Department of Engineering Mechanics,Wuhan University,Wuhan,Hubei,430000,China
4.Frontier Research Center for Applied Atomic Sciences,Ibaraki University,Ibaraki,Japan

Chu，Kangjie,Wang，Bing,Li，Qiao,et al. Grain size effect on the temperature-dependence of elastic modulus of nanocrystalline NiTi[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2023,934.

Chu，Kangjie,Wang，Bing,Li，Qiao,Onuki，Yusuke,&Ren，Fuzeng.(2023).Grain size effect on the temperature-dependence of elastic modulus of nanocrystalline NiTi.JOURNAL OF ALLOYS AND COMPOUNDS,934.

Chu，Kangjie,et al."Grain size effect on the temperature-dependence of elastic modulus of nanocrystalline NiTi".JOURNAL OF ALLOYS AND COMPOUNDS 934(2023).