Phase Evolution and Thermal Expansion Behavior of a γ′ Precipitated Ni-Based Superalloy by Synchrotron X-Ray Diffraction

2021 ◽  
Author(s):  
Zhiran Yan ◽  
Qing Tan ◽  
Hua Huang ◽  
Hailong Qin ◽  
Yi Rong ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Phase Evolution ◽  
X Ray Diffraction ◽  
Thermal Expansion Behavior ◽  
X Ray ◽  
Expansion Behavior

Preparation and Anisotropic Lattice Thermal Expansion of Hexagonal Cordierite

2017 ◽  
Vol 726 ◽  
pp. 470-477
Author(s):  
Jin Hua Zhang ◽  
Chang Ming Ke ◽  
Hong Dan Wu ◽  
Ji Shun Yu
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Least Squares Method ◽  
Rietveld Method ◽  
X Ray Diffraction ◽  
Lattice Thermal Expansion ◽  
Thermal Expansion Behavior ◽  
X Ray ◽  
Expansion Behavior

The hexagonal cordierite was synthesized by the reverse coprecipitation-calcination method and characterized by powder X-ray diffraction. The lattice thermal expansion behavior of hexagonal cordierite was investigated by high temperature X-ray diffraction in the temperature range 298-1273 K. The lattice parameters of the hexagonal cordierite at different temperature were calculated by a least squares method. The hexagonal cordierite expressed anisotropic thermal expansion behavior with the average lattice thermal expansion coefficient were 2.13×10-6 K-1 along a or b axis and-1.03×10-6 K-1 along c axis from room temperature to 1273 K. The crystal structure of hexagonal cordierite at 298 K and 1273 K were refined by Rietveld method. The thermal expansion coefficient of the height of the [MgO6]-[AlO4] polyhedral layer is-1.8×10-6 K-1. Although the six-member ring expressed the normal positive thermal expansion along arbitrary direction, the height thermal expansion coefficient of the six-member ring is just 0.6×10-6 K-1.

Large negative thermal expansion and phase transition in (Pb1−xCax)TiO3 (0.30 ≤ x ≤ 0.45) ceramics

2005 ◽  
Vol 20 (2) ◽  
pp. 350-356 ◽  
Author(s):  
Amreesh Chandra ◽  
Dhananjai Pandey ◽  
M.D. Mathews ◽  
A.K. Tyagi
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Negative Thermal Expansion ◽  
Ferroelectric Ceramics ◽  
X Ray Diffraction ◽  
Thermal Expansion Behavior ◽  
X Ray ◽  
Expansion Behavior ◽  
Wide Range

High-temperature dilatometric studies on (Pb1−xCax)TiO3 (x = 0.35, 0.35, 0.40, 0.45) ferroelectric ceramics reveal negative thermal expansion for x ≤ 0.40. The negative thermal expansion coefficient for x = 0.30, as obtained by dilatometry and powder x-ray diffraction, were found to be −8.541 × 10−6 K−1 and −11 × 10−6 K−1, respectively, which are comparable to those of other well-known negative thermal expansion materials like ZrW2O8, NaZr2(PO4)3. Results of temperature-dependent x-ray diffraction studies are also presented to show that the large negative thermal expansion behavior for x = 0.30 persists in a very wide range of temperatures, 70–570 K. Ca2+ substitution reduces the value of the negative thermal expansion coefficient of pure PbTiO3 crystal, but it enables the preparation of strong sintered ceramic bodies. The negative thermal expansion behavior is shown to disappear above the ferroelectric Curie point and is restricted to only the tetragonal compositions of (Pb1−xCax)TiO3.

Structure and Thermal Expansion Behavior of Dy2-xGdxMo4O15 Solid Solution

2008 ◽  
Vol 368-372 ◽  
pp. 1665-1667
Author(s):  
M.M. Wu ◽  
X.L. Xiao ◽  
Y.Z. Cheng ◽  
J. Peng ◽  
D.F. Chen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Thermal Expansion ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Expansion Behavior ◽  
Expansion Coefficients ◽  
Cell Volumes

A new series of solid solutions Dy2-xGdxMo4O15 (x = 0.0-0.9) were prepared. These compounds all crystallize in monoclinic structure with space group P21/c. The lattice parameters a, b, c and unit cell volumes V increase almost linearly with increasing gadolinium content. The intrinsic thermal expansion coefficients of Dy2-xGdxMo4O15 (x = 0.0 and 0.25) were obtained in the temperature range of 25 to 500°C with high-temperature X-ray diffraction. The correlation between thermal expansion and crystal structure was discussed.

Synchrotron X-ray fiber diffraction study on the thermal expansion behavior of cellulose crystals in tension wood of Japanese poplar in the low-temperature region

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Hitomi Hidaka ◽  
Ung-Jin Kim ◽  
Masahisa Wada
Keyword(s):  
Thermal Expansion ◽  
Temperature Region ◽  
Tension Wood ◽  
Linear Thermal Expansion ◽  
Thermal Expansion Behavior ◽  
X Ray ◽  
Cell Parameters ◽  
Bonding System ◽  
Fiber Diffraction ◽  
Expansion Behavior

Abstract The thermal expansion behavior of tension wood cellulose obtained from Populus maximowiczii A. Henry was investigated by synchrotron X-ray fiber diffraction at temperatures ranging from 100 to 300 K. Three equatorial and one meridional d-spacings indexed as , 110, 200, and 004 showed a gradual linear increase with increasing temperature. Unit-cell parameters calculated from the changes in these d-spacings showed anisotropic thermal expansion behavior in the three axial directions related to the crystal structure and hydrogen-bonding system of cellulose Iβ. The linear thermal expansion coefficients (TECs) of the a-, b-, and c-axes were: α a=5.2×10-5 K-1, α b=2.1×10-5 K-1, and α c=0.4×10-5 K-1, respectively. The volume TEC was β=7.8×10-5 K-1, which was approximately 70% of previously reported values in the high-temperature region from room temperature to 250°C.

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