Effects of Static Magnetic Field and Hydrostatic Pressure on the Isothermal Martensitic Transformation in an Fe&ndash;Ni&ndash;Cr Alloy

We have investigated athermal and isothermal martensitic transformations (typical displacive transformations) in Fe–Ni, Fe–Ni–Cr, and Ni-Co-Mn-In alloys under magnetic fields and hydrostatic pressures in order to understand the time-dependent nature of martensitic transformation, that is, the kinetics of martensitic transformation. We have confirmed that the two transformation processes are closely related to each other, that is, the athermal process changes to the isothermal process and the isothermal process changes to the athermal one under a hydrostatic pressure or a magnetic field. These findings can be explained by the phenomenological theory, which gives a unified explanation for the two transformation processes previously proposed by our group.

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Effect of Magnetic Field on Successive ^|^gamma;^|^rarr;^|^epsilon;^|^prime;^|^rarr;^|^alpha;^|^prime; Isothermal Martensitic Transformation in a SUS304L Stainless Steel

ISIJ International ◽

10.2355/isijinternational.52.1366 ◽

2012 ◽

Vol 52 (7) ◽

pp. 1366-1369 ◽

Cited By ~ 2

Author(s):

Ju-young Choi ◽

Takashi Fukuda ◽

Tomoyuki Kakeshita

Keyword(s):

Magnetic Field ◽

Stainless Steel ◽

Martensitic Transformation ◽

Isothermal Martensitic Transformation

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Isothermal Martensitic Transformation of γ-FeN in a Magnetic Field

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.44.2541 ◽

2003 ◽

Vol 44 (12) ◽

pp. 2541-2544 ◽

Cited By ~ 4

Author(s):

Tamotsu Koyano

Keyword(s):

Magnetic Field ◽

Martensitic Transformation ◽

Isothermal Martensitic Transformation

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Martensitic Transformation of Ni-Mn-Ga Alloys under Magnetic Field and Hydrostatic Pressure

Materials Science Forum ◽

10.4028/www.scientific.net/msf.512.189 ◽

2006 ◽

Vol 512 ◽

pp. 189-194 ◽

Cited By ~ 3

Author(s):

Jae Hoon Kim ◽

Takashi Fukuda ◽

Tomoyuki Kakeshita

Keyword(s):

Magnetic Field ◽

Hydrostatic Pressure ◽

Martensitic Transformation ◽

Applied Magnetic Field ◽

Transformation Temperature ◽

Intermediate Phase ◽

Parent Phase ◽

Clapeyron Equation ◽

Transformation Temperatures ◽

The Magnetic Field

The effects of magnetic field and hydrostatic pressure on martensitic transformation have been systematically investigated by using Ni2MnGa, Ni2.14Mn0.84Ga1.02, and Ni2.14Mn0.92Ga0.94, which exhibit P(parent phase)-I(intermediate phase)-10M, P-14M-2M, and P-2M transformation, respectively. The following results were obtained. (i) The P-I transformation temperature does not change by magnetic field. (ii) The I-10M and the P-14M transformation temperatures decrease under applied magnetic field up to 0.8 MA/m and 0.4 MA/m, respectively, and then increase with increasing applied magnetic field higher than those fields. (iii) The 14M-2M transformation temperature increases under a magnetic field up to 0.4 MA/m and decreases under magnetic field up to 0.8 MA/m and then increases again when the magnetic field becomes higher than 0.8 MA/m. (iv) The P-2M transformation temperature increases linearly with increasing applied magnetic field. (v) All transformation temperatures increase linearly with increasing hydrostatic pressure. The experimental results mentioned above (i)~(iv) under magnetic field can be well explained by using the Clausius-Clapeyron equation.

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Effect of External Fields on the Martensitic Transformation in Ni-Mn Based Heusler Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.52.189 ◽

2008 ◽

Vol 52 ◽

pp. 189-197 ◽

Cited By ~ 3

Author(s):

Xavier Moya ◽

Lluís Mañosa ◽

Antoni Planes ◽

Seda Aksoy ◽

Mehmet Acet ◽

...

Keyword(s):

Magnetic Field ◽

Hydrostatic Pressure ◽

Martensitic Transformation ◽

Applied Magnetic Field ◽

Heusler Alloys ◽

Applied Pressure ◽

Large Change ◽

Entropy Change ◽

Martensitic Transition ◽

External Fields

In this paper, we discuss the possibility of inducing a martensitic transition by means of an applied magnetic field or hydrostatic pressure in Ni-Mn based Heusler shape memory alloys. We report on the shift of the martensitic transition temperatures with applied magnetic field and applied pressure and we show that it is possible to induce the structural transformation in a Ni50Mn34In16 alloy by means of both external fields due to: (i) the low value of the entropy change and (ii) the large change of magnetization and volume, which occur at the martensitic transition.

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