Molecular Dynamics Investigation of the Influence of Voids on the Impact Mechanical Behavior of NiTi Shape-Memory Alloy
| Autor: | Xiang Chen, Hengwei Zheng, Zhenwei Wu, Zhao Yang, Tao Fu |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Shock wave
Technology Materials science NiTi alloy 02 engineering and technology 01 natural sciences Article Stress (mechanics) 0103 physical sciences voids General Materials Science Composite material Astrophysics::Galaxy Astrophysics 010302 applied physics Austenite Microscopy QC120-168.85 QH201-278.5 Shape-memory alloy 021001 nanoscience & nanotechnology Engineering (General). Civil engineering (General) shock behavior Shock (mechanics) TK1-9971 martensitic transformation molecular dynamics simulation Descriptive and experimental mechanics Nickel titanium Diffusionless transformation Martensite Electrical engineering. Electronics. Nuclear engineering TA1-2040 0210 nano-technology shape-memory alloy |
| Zdroj: | Materials Volume 14 Issue 14 Materials, Vol 14, Iss 4020, p 4020 (2021) |
| ISSN: | 1996-1944 |
| DOI: | 10.3390/ma14144020 |
| Popis: | To date, research on the physical and mechanical behavior of nickel-titanium shape-memory alloy (NiTi SMA) has focused on the macroscopic physical properties, equation of state, strength constitution, phase transition induced by temperature and stress under static load, etc. The behavior of a NiTi SMA under high-strain-rate impact and the influence of voids have not been reported. In this present work, the behavior evolution of (100) single-crystal NiTi SMA and the influencing characteristics of voids under a shock wave of 1.2 km/s are studied by large-scale molecular dynamics calculation. The results show that only a small amount of B2 austenite is transformed into B19’ martensite when the NiTi sample does not pass through the void during impact compression, whereas when the shock wave passes through the hole, a large amount of martensite phase transformation and plastic deformation is induced around the hole the existence of phase transformation and phase-transformation-induced plastic deformation greatly consumes the energy of the shock wave, thus making the width of the wave front in the subsequent propagation process wider and the peak of the foremost wave peak reduced. In addition, the existence of holes disrupts the orderly propagation of shock waves, changes the shock wave front from a plane to a concave surface, and reduces the propagation speed of shock waves. The calculation results show that the presence of pores in a porous NiTi SMA leads to significant martensitic phase transformation and plastic deformation induced by phase transformation, which has a significant buffering effect on shock waves. The results of this study provide great guidance for expanding the application of NiTi SMA in the field of shock. |
| Databáze: | OpenAIRE |
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