### Abstract

The effect of hydrostatic pressures on martensitic phase transformations in near-equiatomic Ti-Ni shape-memory alloys has been investigated up to 1.5 GPa. The relative volume changes ΔV_{c}/V and the entropy changes ΔS_{c} have also been determined at atmospheric pressure. Supposing that the volume derivative of the elastic energy differs from zero at the martensite start (and austenite finish) temperatures as well, that is e_{0} ≠ 0, and that the Clausius-Clapeyron equation is valid for the equilibrium transformation temperature T_{0}, it was shown that the dissipative energy terms were approximately zero for the B2-R transition. For the R → B19′ transformation this energy was independent of pressure, while for the reverse transformation it had a definite pressure dependence. The pressure derivatives of elastic energy e_{m} (which corresponds to the martensite finish or austenite start) and e_{0} are similar in both directions for the R-B19′ transformations, while for the B2-R transition it is negative for e_{0}.

Original language | English |
---|---|

Pages (from-to) | 105-120 |

Number of pages | 16 |

Journal | Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties |

Volume | 82 |

Issue number | 1 |

DOIs | |

Publication status | Published - Jan 10 2002 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)
- Chemical Engineering(all)

### Cite this

*Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties*,

*82*(1), 105-120. https://doi.org/10.1080/13642810110066452

**Effect of hydrostatic pressure on the martensitic transformation in near equiatomic Ti-Ni alloys.** / Daróczi, L.; Beke, D.; Lexcellent, C.; Mertinger, V.

Research output: Contribution to journal › Article

*Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties*, vol. 82, no. 1, pp. 105-120. https://doi.org/10.1080/13642810110066452

}

TY - JOUR

T1 - Effect of hydrostatic pressure on the martensitic transformation in near equiatomic Ti-Ni alloys

AU - Daróczi, L.

AU - Beke, D.

AU - Lexcellent, C.

AU - Mertinger, V.

PY - 2002/1/10

Y1 - 2002/1/10

N2 - The effect of hydrostatic pressures on martensitic phase transformations in near-equiatomic Ti-Ni shape-memory alloys has been investigated up to 1.5 GPa. The relative volume changes ΔVc/V and the entropy changes ΔSc have also been determined at atmospheric pressure. Supposing that the volume derivative of the elastic energy differs from zero at the martensite start (and austenite finish) temperatures as well, that is e0 ≠ 0, and that the Clausius-Clapeyron equation is valid for the equilibrium transformation temperature T0, it was shown that the dissipative energy terms were approximately zero for the B2-R transition. For the R → B19′ transformation this energy was independent of pressure, while for the reverse transformation it had a definite pressure dependence. The pressure derivatives of elastic energy em (which corresponds to the martensite finish or austenite start) and e0 are similar in both directions for the R-B19′ transformations, while for the B2-R transition it is negative for e0.

AB - The effect of hydrostatic pressures on martensitic phase transformations in near-equiatomic Ti-Ni shape-memory alloys has been investigated up to 1.5 GPa. The relative volume changes ΔVc/V and the entropy changes ΔSc have also been determined at atmospheric pressure. Supposing that the volume derivative of the elastic energy differs from zero at the martensite start (and austenite finish) temperatures as well, that is e0 ≠ 0, and that the Clausius-Clapeyron equation is valid for the equilibrium transformation temperature T0, it was shown that the dissipative energy terms were approximately zero for the B2-R transition. For the R → B19′ transformation this energy was independent of pressure, while for the reverse transformation it had a definite pressure dependence. The pressure derivatives of elastic energy em (which corresponds to the martensite finish or austenite start) and e0 are similar in both directions for the R-B19′ transformations, while for the B2-R transition it is negative for e0.

UR - http://www.scopus.com/inward/record.url?scp=0037050622&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037050622&partnerID=8YFLogxK

U2 - 10.1080/13642810110066452

DO - 10.1080/13642810110066452

M3 - Article

AN - SCOPUS:0037050622

VL - 82

SP - 105

EP - 120

JO - Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties

JF - Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties

SN - 1364-2812

IS - 1

ER -