Thermal Expansion of Iron during the α → γ Phase Transformation by a Transient Interferometric Technique

1984 ◽  
pp. 245-258 ◽  
Author(s):  
A. P. Miiller ◽  
A. Cezairliyan
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Interferometric Technique

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Transformation behavior of yttria stabilized tetragonal zirconia polycrystal–TiB2 composites

2001 ◽  
Vol 16 (7) ◽  
pp. 2158-2169 ◽  
Author(s):  
B. Basu ◽  
J. Vleugels ◽  
O. Van Der Biest
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Low Temperature ◽  
Tetragonal Zirconia ◽  
Mechanical Analysis ◽  
Transformation Behavior ◽  
Thermal Expansion Data ◽  
Thermally Induced ◽  
First Time ◽  
Tetragonal Zirconia Polycrystal

The objective of the present article is to study the influence of TiB2 addition on the transformation behavior of yttria stabilized tetragonal zirconia polycrystals (Y-TZP). A range of TZP(Y)–TiB2 composites with different zirconia starting powder grades and TiB2 phase contents (up to 50 vol%) were processed by the hot-pressing route. Thermal expansion data, as obtained by thermo-mechanical analysis were used to assess the ZrO2 phase transformation in the composites. The thermal expansion hysteresis of the transformable ceramics provides information concerning the transformation behavior in the temperature range of the martensitic transformation and the low-temperature degradation. Furthermore, the transformation behavior and susceptibility to low-temperature degradation during thermal cycling were characterized in terms of the overall amount and distribution of the yttria stabilizer, zirconia grain size, possible dissolution of TiB2 phase, and the amount of residual stress generated in the Y-TZP matrix due to the addition of titanium diboride particles. For the first time, it is demonstrated in the present work that the thermally induced phase transformation of tetragonal zirconia in the Y-TZP composites can be controlled by the intentional addition of the monoclinic zirconia particles into the 3Y-TZP matrix.

scholarly journals Real-time observation of the thermally-induced phase transformation in GeTe and its thermal expansion properties

2019 ◽  
Vol 165 ◽  
pp. 327-335 ◽  
Author(s):  
Xuan Quy Tran ◽  
Min Hong ◽  
Hiroshi Maeno ◽  
Youichirou Kawami ◽  
Takaaki Toriyama ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Real Time ◽  
Thermally Induced ◽  
Time Observation ◽  
Real Time Observation

Phase Transformation and Thermal Expansion of Zirconium and Hafnium Titanates and Their Solid Solutions

1988 ◽  
Vol 71 (2) ◽  
pp. 120-127 ◽  
Author(s):  
HIROYUKI IKAWA ◽  
AKIHITO IWAI ◽  
KAZUYUKI HIRUTA ◽  
HIROMASA SHIMOJIMA ◽  
KAZUYORI URABE ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Solid Solutions

An Approach for Modeling Transformation Plasticity Using a Phase Field Model

2011 ◽  
Vol 320 ◽  
pp. 285-290 ◽  
Author(s):  
Takuya Uehara
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Phase Field ◽  
Transformation Temperature ◽  
Field Model ◽  
Volume Fraction ◽  
Phase Field Model ◽  
Field Variable ◽  
Transformation Plasticity ◽  
Temperature Strain

In this paper, an approach for modeling transformation plasticity using a phase field model is presented. A conventional formula is utilized to represent the strain due to transformation plasticity as well as thermal expansion and transformation dilatation. A phase-field variable is introduced to express the state of phase in material instead of volume fraction, and numerical simulations under simplified conditions are demonstrated. As a result, the strain induced by phase transformation is suitably regenerated, and qualitatively appropriate temperature-strain curves are obtained. In addition, the effect of each parameter is investigated, and various dependencies, such as transformation temperature and stress, on the induced strain are demonstrated. It is then concluded that the results indicate the applicability of the presented model for practical use by adjusting the parameters.

Phase Transformation Cycle β→ α′ + α + α"→ β in Ti6Al4V Alloy

2015 ◽  
Vol 828-829 ◽  
pp. 232-238 ◽  
Author(s):  
Kalenda Mutombo ◽  
Siyasiya Charles ◽  
Waldo Stumpf
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Phase Field ◽  
Xrd Analysis ◽  
External Stress ◽  
Ti6al4v Alloy ◽  
Β Phase ◽  
Α Phase ◽  
Sequential Transformation ◽  
Dsc Thermograms

The β-phase transforms to α′, α and α" within a range of temperature from the β-transus (Tβ) to about 600°C, considering no external stress is applied. Two types of microstructure were obtained: acicular martensite when rapidly cooled and lamellar α/β when slowly cooled from the β phase field. The sequential transformation of β into α′, α-phase, α2, and α" was revealed as peaks on the coefficient thermal expansion (CTE) curves, however, reversed transformations: α"→β, and α→β, were revealed by the DSC thermograms. The presence of β, α′, α, α2 and α" was identified by means of XRD analysis and HRTEM.

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