Abstract
In this study, spherical indentation responses of room temperature superelastic (homogenized Ni50.8Ti49.2 and 400°C 3 h aged Ni45.3Ti29.7Hf20Pd5) and nonsuperelastic (Ni49.9Ti50.1 and 600°C 3 h aged Ni45.3Ti29.7Hf20Pd5) are revealed as functions of maximum loading level in nano and macro scales. Experimental results showed that for all alloys, the depth and work recovery ratio decrease and then saturate with hmax/R. In contrast, indentation hardness increases and then saturates with indentation depth. Both NiTi and NiTiHfPd alloys have higher hardness in austenite than in martensite. NiTiHfPd alloys have a higher indentation hardness than NiTi alloys which was attributed to the higher strength of NiTiHfPd alloys.
| Original language | English |
|---|---|
| Pages (from-to) | 724-730 |
| Number of pages | 7 |
| Journal | Journal of Alloys and Compounds |
| Volume | 651 |
| DOIs | |
| State | Published - Dec 5 2015 |
Bibliographical note
Publisher Copyright:© 2015 Elsevier B.V. All rights reserved.
Funding
This work was supported by the NASA EPSCOR (grant No: NNX11AQ31A ), National Science Foundation (grant No: 0959896 ) and the Kentucky Science and Engineering Foundation (grant No: KSEF-1718-RDE-011 ).
| Funders | Funder number |
|---|---|
| U.S. Department of Energy Chinese Academy of Sciences Guangzhou Municipal Science and Technology Project Oak Ridge National Laboratory Extreme Science and Engineering Discovery Environment National Science Foundation National Energy Research Scientific Computing Center National Natural Science Foundation of China | 0959896 |
| Kentucky Science and Engineering Foundation | KSEF-1718-RDE-011 |
| National Aeronautics and Space Administration | NNX11AQ31A |
Keywords
- Hardness
- NiTi
- NiTiHfPd alloys
- Phase transformation
- Shape memory alloys
- Spherical indentation
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry