In situ observation of stress-induced martensitic transformation and plastic deformation in TiNi alloy

1997 ◽  
Vol 238 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Xiaoping Jiang ◽  
Moritaka Hida ◽  
Yoshito Takemoto ◽  
Akira Sakakibara ◽  
Hidehiro Yasuda ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Martensitic Transformation ◽  
Tini Alloy ◽  
In Situ Observation

In situ observation of the martensitic transformation in (Mg,Y)-PSZ

1986 ◽  
Vol 44 ◽  
pp. 500-501
Author(s):  
R-R. Lee
Keyword(s):  
Martensitic Transformation ◽  
High Strength ◽  
Nucleation And Growth ◽  
In Situ Observation ◽  
Considerable Potential ◽  
Transmission Electron ◽  
Structural Applications ◽  
Applied Stresses ◽  
Kinetics Of

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.

In situ observation of martensitic transformation in air-hardened 6Cr-1Mo-1C steel through hot-stage microscopy

1988 ◽  
Vol 7 (5) ◽  
pp. 435-436
Author(s):  
Amitava Ray ◽  
Santanu Kr. Ray ◽  
R. N. Mukherjee ◽  
S. R. Mediratta
Keyword(s):  
Martensitic Transformation ◽  
In Situ Observation ◽  
Hot Stage Microscopy

scholarly journals In-situ observation of bulk 3D grain evolution during plastic deformation in polycrystalline Cu

2015 ◽  
Vol 67 ◽  
pp. 217-234 ◽  
Author(s):  
Reeju Pokharel ◽  
Jonathan Lind ◽  
Shiu Fai Li ◽  
Peter Kenesei ◽  
Ricardo A. Lebensohn ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
In Situ Observation

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

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.

scholarly journals Novel −75°C SEM cooling stage: application for martensitic transformation in steel

Microscopy ◽  
2020 ◽  
Author(s):  
Kaneaki Tsuzazki ◽  
Motomichi Koyama ◽  
Ryosuke Sasaki ◽  
Keiichiro Nakafuji ◽  
Kazushi Oie ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Electron Backscatter Diffraction ◽  
Dislocation Slip ◽  
In Situ Observation ◽  
Contrast Imaging ◽  
Cooling Stage ◽  
Electron Channelling ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Abstract Microstructural changes during the martensitic transformation from face-centred cubic (FCC) to body-centred cubic (BCC) in an Fe-31Ni alloy were observed by scanning electron microscopy (SEM) with a newly developed Peltier stage available at temperatures to  −75°C. Electron channelling contrast imaging (ECCI) was utilized for the in situ observation during cooling. Electron backscatter diffraction analysis at ambient temperature (20°C) after the transformation was performed for the crystallographic characterization. A uniform dislocation slip in the FCC matrix associated with the transformation was detected at −57°C. Gradual growth of a BCC martensite was recognized upon cooling from −57°C to −63°C.

In situ TEM study of irradiation-induced transformation in TiNi shape memory alloys

2003 ◽  
Vol 792 ◽  
Author(s):  
X. T. Zu ◽  
F.R. Wan ◽  
S. Zhu ◽  
L. M. Wang
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Electron Irradiation ◽  
Room Temperature ◽  
Critical Voltage ◽  
In Situ Tem ◽  
In Situ Observation

ABSTRACTTiNi shape memory alloy (SMA) has potential applications for nuclear reactors and its phase stability under irradiation is becoming an important topic. Some irradiation-induced diffusion-dependent phase transformations, such as amorphization, have been reported before. In the present work, the behavior of diffusion-independent phase transformation in TiNi SMA was studied by electron irradiation at room temperature. The effect of irradiation on the martensitic transformation of TiNi shape memory alloys was studied by Transmission Electron Microscopy (TEM) with in-situ observation and differential scanning calorimeter (DSC). The results of TEM and DSC measurements show that the microstructure of samples is R phase at room temperature. Electron irradiations were carried out using several different TEM with accelerating voltage of 200 kV, 300 kV, 400 kV and 1000 kV. Also the accelerating voltage in the same TEM was changed to investigate the critical voltage for the effect of irradiation on phase transformation. It was found that a phase transformation occurred under electron irradiation above 320 kV, but never appeared at 300 kV or lower accelerating voltage. Such phase transformation took place in a few seconds of irradiation and was independent of atom diffusion. The mechanism of Electron-irradiation-induced the martensitic transformation due to displacements of atoms from their lattice sites produced by the accelerated electrons.

In-situ observation of reversible twinning in U3Si

1978 ◽  
Vol 36 (1) ◽  
pp. 572-573
Author(s):  
G. Kimmel ◽  
U. Admon ◽  
A. Zangvil
Keyword(s):  
Plastic Deformation ◽  
Intermetallic Compound ◽  
Optical Metallography ◽  
External Stress ◽  
Point Of View ◽  
In Situ Observation ◽  
Martensitic Structure ◽  
Principal Stress Direction ◽  
Double Shear

The intermetallic compound U3Si has the cubic δ' structure between 765-900°C, and the tetragonal δ structure at lower temperatures. The δ' → δ transition always results in a twinned martensitic structure. Double shear causes the appearance of bands and sub-bands (1).Plastic deformation of martensitic U3Si is accompanied by detwinning, since only one of the twins is usually favorable from the point of view of the external stress. This was confirmed by optical metallography as well as by texture analysis (2).The present work describes a memory effect observed during a study of plastically deformed (⩽2%) martensitic U3Si.TEM specimens were prepared from lateral sections of standard tensile test samples. The principal stress direction was thus perpendicular to the foil.Fig. 1 shows the twinned structure of the martensite before deformation.Primary and secondary twins can be seen. The twinning systems are {101}<101> in FCT coordinates ({112}<111> in BCT coordinates). This was inferred from trace analyses.

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