Strain variation during the isothermal martensitic transformation in Ti40.7Hf9.5Ni44.8Cu5 alloy

Abstract The strain variation during the isothermal holding under constant stress was studied in the quenched or annealed Ni51Ti49 alloy samples. The isothermal strain variation was found in both samples and this strain was completely recovered on subsequent unloading and heating. This allowed to conclude that the strain variation on holding was caused by the isothermal martensitic transformation. It was found that the maximum value of isothermal strain depended on the alloy heat treatment. This value was equal to 0.5 % in annealed sample and it was equal to 6 % in quenched sample. It was assumed that the formation of the Ni4Ti3 phase during annealing led to a decrease in concentration of substitutional Ni atoms in NiTi phase that were responsible for the isothermal transformation. As a result, the less volume fraction of the martensite formed during holding that supresses the strain variation in annealed samples.

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Strain variation in the Ti40,7Hf9,5Ni41,8Cu8 alloy during isothermal martensitic transformation under a constant stress

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1213/1/012007 ◽

2022 ◽

Vol 1213 (1) ◽

pp. 012007

Author(s):

E Demidova ◽

P Pchelnikov ◽

S Belyaev ◽

N Resnina ◽

A Shelyakov

Keyword(s):

Martensitic Transformation ◽

Constant Stress ◽

Strain Variation ◽

Maximum Value ◽

Optimal Value ◽

Isothermal Martensitic Transformation ◽

Holding Temperature

Abstract Strain variation on holding under a constant stress was studied in the Ti40,7Hf9,5Ni41,8Cu8 alloy. It was found, that on holding under stress, the isothermal strain rose up to saturation, which value depended on holding temperature and stress. It was found that the dependencies of the isothermal strain on the holding temperature and stress were non-monotonic. This allowed to find the optimal value of stress and time at which the isothermal strain attained the maximum value of 3.2 %. It was found that the maximum isothermal strain in the Ti40,7Hf9,5Ni41,8Cu8 alloy was less than in the Ti40,7Hf9,5Ni44,8Cu5 alloy.

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A physically based model for the isothermal martensitic transformation in a maraging steel

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2003919 ◽

2003 ◽

Vol 112 ◽

pp. 437-440 ◽

Cited By ~ 1

Author(s):

S. O. Kruijver ◽

H. S. Blaauw ◽

J. Beyer ◽

J. Post

Keyword(s):

Martensitic Transformation ◽

Maraging Steel ◽

Physically Based Model ◽

Physically Based ◽

Isothermal Martensitic Transformation

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Isothermal martensitic transformation in polycrystalline Ni50Mn29Ga21

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2010.01.044 ◽

2010 ◽

Vol 494 (1-2) ◽

pp. 40-43 ◽

Cited By ~ 11

Author(s):

C. Hürrich ◽

S. Roth ◽

M. Pötschke ◽

B. Rellinghaus ◽

L. Schultz

Keyword(s):

Martensitic Transformation ◽

Isothermal Martensitic Transformation

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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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Some Characteristics of the Isothermal Martensitic Transformation

JOM ◽

10.1007/bf03377476 ◽

1955 ◽

Vol 7 (1) ◽

pp. 183-187 ◽

Cited By ~ 5

Author(s):

C. H. Shih ◽

B. L. Averbach ◽

Morris Cohen

Keyword(s):

Martensitic Transformation ◽

Isothermal Martensitic Transformation

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Effect of Plastic Deformation on the Isothermal FCC/HCP Phase Transformation during Aging of Co-27Cr-5Mo-0.05C Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.560.23 ◽

2007 ◽

Vol 560 ◽

pp. 23-28

Author(s):

A. Mani-Medrano ◽

Armando Salinas-Rodríguez

Keyword(s):

Plastic Deformation ◽

Martensitic Transformation ◽

Tensile Deformation ◽

Internal Stresses ◽

X Ray Diffraction ◽

Thermally Activated ◽

Prior Plastic Deformation ◽

Last Stage ◽

Isothermal Martensitic Transformation

The effects of tensile deformation on the amount of hcp phase formed during a 3 hour isothermal aging at 800 °C is studied using in-situ X-ray diffraction and scanning electron microscopy. It is shown that the start of the isothermal martensitic transformation during aging of this material is delayed by prior plastic deformation. Nevertheless, the total amount of hcp phase present in the microstructure at the beginning of aging increases at a continuously decreasing rate due to stress-assisted transformation. This behavior is attributed to the relieving of internal stresses produced by plastic deformation prior to aging. Finally, during the last stage of aging, the amount of hcp phase in the microstructure increases as a result of isothermal martensitic transformation. It is suggested that the presence of mechanically-induced hcp phase during aging inhibits the thermally activated nucleation process that leads to the isothermal martensitic transformation.

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