Shape memory behavior of Ni40.3Ti39.7Hf15Pd5 and Ni40.3Ti44.7Hf10Pd5 alloys
| Autor: | Haluk E. Karaca, Osman E. Ozbulut, Soheil Saedi, Emre Acar, Guher P. Toker |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Strain (chemistry) Mechanical Engineering Metals and Alloys 02 engineering and technology Shape-memory alloy 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Stress (mechanics) Mechanics of Materials Nickel titanium 0103 physical sciences Pseudoelasticity Thermal Materials Chemistry Heat treated Composite material 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 763:1012-1017 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2018.05.029 |
| Popis: | The microstructure and shape memory properties of Ni40.3Ti39.7Hf15Pd5 and Ni40.3Ti44.7Hf10Pd5 alloys were investigated. It was revealed that transformation temperatures of these alloys can be tailored by thermal treatments and composition alteration. Heat treated Ni40.3Ti39.7Hf15Pd5 can show shape memory effect at above 100 °C. Both alloys showed shape memory effect, however, superelasticity was not observed due to the large thermal hysteresis and high rate of increase in transformation temperatures with stress. Both alloys have higher strength but considerably lower transformation strain than NiTi. Microstructure features also were investigated for grains, distribution and composition of secondary phase. It was revealed that secondary phases lead to decrease the recoverable strains of the NiTiHfPd alloys. As-received Ni40.3Ti44.7Hf10Pd5 and Ni40.3Ti39.7Hf15Pd5 have recoverable strains of 1.12% and 0.43% under 700 MPa, respectively. |
| Databáze: | OpenAIRE |
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