Improved functional fatigue resistance of single crystalline NiTi micropillars with uniformly oriented Ti3Ni4 precipitates

Xiao，Fei1,3,4; Chu，Kangjie2; Li，Zhu1; Hou，Ruihang1,3; Gao，Yipeng5,6; Sun，Qingping7; Jin，Xuejun1,3

2022

10.1016/j.ijplas.2022.103480

INTERNATIONAL JOURNAL OF PLASTICITY   Impact Factor & Quartile

0749-6419

1879-2154

Superelasticity is one promising functional property of shape memory alloys. To utilize superelasticity in application, sufficient fatigue life (i.e., for functional fatigue) during the mechanical cyclic phase transformation is one of the most important issues to be solved. Here, we successfully manufactured the NiTi single crystalline micropillars which exhibit different crystalline orientations, with uniformly oriented TiNi precipitates and few defects. The mechanical properties of these NiTi single crystalline micropillars were systematically investigated. The NiTi single crystalline micropillar with the [20 2_ 9] (B2: parent phase) crystalline orientation showed quite stable superelasticity during the cyclic compression, which sustained more than 10 phase transformation cycles with only 8% decay (from 5.1% for the 1st cycle to 4.7% for the 10 cycle). Meanwhile, as the cyclic number increased, the stress-strain curves became more stable, and the critical stress for inducing martensitic transformation (from 574 MPa for the 1st cycle to 312 MPa for the 10 cycle) and the stress hysteresis (from 7.2 MJ/m for the 1st cycle to 3.0 MJ/m for the 10 cycle) during the loading-unloading processes both decreased. By analyzing the dislocation plasticity assisted by cyclic martensitic transformations, we show that specific martensite variants are selected biasedly by the interplay of external load and inhomogeneous stress field caused by uniformly oriented TiNi precipitates, which lead to a number of slip systems effectively impeded by the precipitates. This study opens a new avenue to develop fatigue resistant shape memory alloy through tailoring the aligned precipitates and preferred crystal orientation.

Functional fatigue Micropillar NiTi shape memory alloy Orientation dependence Ti3Ni4 precipitate

SCI

English

Others

National Natural Science Foundation of China["52022055","52031005","51871151","52211530096","52171116","U22A20109"] ; National Key R&D Program of China[2022YFB4702703] ; Natural Science Foundation of Shanghai[20ZR1428800] ; Oceanic Interdisciplinary Program of Shanghai Jiao Tong University[SL2021MS012] ; Science and Interdisciplinary Integration and Innovation Project of JLU[JLUXKJC2021ZZ08] ; Shenzhen Science and Technology Program[JCYJ20220530113017040]

Engineering ; Materials Science ; Mechanics

Engineering, Mechanical ; Materials Science, Multidisciplinary ; Mechanics

WOS:000924615000001

PERGAMON-ELSEVIER SCIENCE LTD

ENGINEERING

2-s2.0-85143335088

Scopus

1.State Key Lab of Metal Matrix Composite, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, P. R. China
2.Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
3.Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai 200240, China
4.Department of Materials Science and Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka 565-0871, Japan
5.Key Laboratory of Automobile Materials of Ministry of Education and School of Materials Science and Engineering, Nanling Campus, Jilin University, No. 5988 Renmin Street, Changchun 130025, China
6.International Center of Future Science, Jilin University, Changchun 130025, China
7.Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China

Xiao，Fei,Chu，Kangjie,Li，Zhu,et al. Improved functional fatigue resistance of single crystalline NiTi micropillars with uniformly oriented Ti3Ni4 precipitates[J]. INTERNATIONAL JOURNAL OF PLASTICITY,2022,160.

Xiao，Fei.,Chu，Kangjie.,Li，Zhu.,Hou，Ruihang.,Gao，Yipeng.,...&Jin，Xuejun.(2022).Improved functional fatigue resistance of single crystalline NiTi micropillars with uniformly oriented Ti3Ni4 precipitates.INTERNATIONAL JOURNAL OF PLASTICITY,160.

Xiao，Fei,et al."Improved functional fatigue resistance of single crystalline NiTi micropillars with uniformly oriented Ti3Ni4 precipitates".INTERNATIONAL JOURNAL OF PLASTICITY 160(2022).