Thermal expansion and phase transformations of nitrogen-expanded austenite studied within situsynchrotron X-ray diffraction

2014 ◽  
Vol 47 (3) ◽  
pp. 819-826 ◽  
Author(s):  
Bastian Brink ◽  
Kenny Ståhl ◽  
Thomas L. Christiansen ◽  
Marcel A. J. Somers
Keyword(s):  
Thermal Expansion ◽  
Nitrogen Content ◽  
Coefficient Of Thermal Expansion ◽  
Steel Powder ◽  
Stacking Fault ◽  
Hydrogen Gas ◽  
X Ray Diffraction ◽  
Linear Coefficient ◽  
X Ray ◽  
Expanded Austenite

Nitrogen-expanded austenite, γN, with high and low nitrogen contents was produced from AISI 316 grade stainless steel powder by gaseous nitriding in ammonia/hydrogen gas mixtures.In situsynchrotron X-ray diffraction was applied to investigate the thermal expansion and thermal stability of expanded austenite in the temperature range 385–920 K. Evaluation of the diffractograms of the sample with a high nitrogen content, corresponding to an occupancy of the interstitial lattice of 56%, with Rietveld refinement yielded a best convergence after including the stacking fault probability as a fitting parameter. The stacking fault density is constant for temperatures up to 680 K, whereafter it decreases to nil. Surprisingly, a transition phase with compositionM4N (M= Fe, Cr, Ni, Mo) appears for temperatures above 770 K. The linear coefficient of thermal expansion depends on the nitrogen content and is lowest for the sample with a high level of nitrogen.

Liquid Crystalline Thermosets As Materials For Microelectronics

1991 ◽  
Vol 227 ◽  
Author(s):  
C. K Ober ◽  
G. G. Barclay
Keyword(s):  
Thermal Expansion ◽  
Liquid Crystalline ◽  
Coefficient Of Thermal Expansion ◽  
High Thermal Stability ◽  
Isotropic Phase ◽  
X Ray Diffraction ◽  
Primary Interest ◽  
Functional Monomers ◽  
X Ray ◽  
Orientation Parameters

ABSTRACTNew liquid crystalline thermosets have been prepared from end-functional monomers and oligomers of varying molecular weight. Both triazine and epoxy networks were explored. Of primary interest was the exploitation of the mesophase properties of these networks for developing polymers with high thermal stability and low coefficients of thermal expansion (CTE). Curing was carried out either within the nematic mesophase or the isotropic phase of the prepolymers. Transition temperatures associated with the mesophase were observed to change after curing under these two sets of conditions. The networks with the highest crosslink density were found to exhibit the lowest CTE values. Crosslinking of these thermosets was also carried out in the presence of a 13.5 Tesla magnetic field to determine the effect of orienting fields on the curing of the LC network. Orientation parameters as measured by wide angle x-ray diffraction were as high as 0.6. Values of the coefficient of thermal expansion as low as 15 ppm were achieved in the aligned direction. Of the two resin types, those with the triazine crosslinks had the lowest thermal expansion coefficient. Other thermal properties of these networks will be discussed.

scholarly journals Тепловое расширение кристаллов Pb-=SUB=-1-x-=/SUB=-Cd-=SUB=-x-=/SUB=-Te

2021 ◽  
Vol 55 (12) ◽  
pp. 1216
Author(s):  
М.К. Шаров
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Solid Solutions ◽  
Coefficient Of Thermal Expansion ◽  
Cadmium Content ◽  
Lattice Period ◽  
Linear Coefficient ◽  
X Ray ◽  
Temperature Range

The values of the lattice period and the linear coefficient of thermal expansion (alfa) of Pb1-xCdxTe solid solutions are determined depending on the cadmium content and temperature using high-temperature X-ray diffractometry. Аn increase in the concentration of cadmium in Pb1-xCdxTe in the range x = 0.02–0.08 leads to a significant increase in the linear coefficient of thermal expansion. A change in temperature range T = 293–673 K leads to decrease in the linear coefficient of thermal expansion. Besides, an increase in temperature does not affect the value alfa of the undoped PbTe in the indicated temperature range.

The Linear Coefficient of Thermal Expansion of Silicon at Room Temperature

1991 ◽  
Vol 6 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Liu Fengchao ◽  
Zheng Bin
Keyword(s):  
Thermal Expansion ◽  
Single Crystal ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Silicon Single Crystal ◽  
Linear Coefficient ◽  
X Ray ◽  
Crystal State ◽  
Powder Diffractometer ◽  
Powder Samples

AbstractThe linear coefficient of thermal expansion for three silicon single-crystal samples, taken from the head, middle, and tail of the same boule, and their powder samples have been measured at room temperature by using an X-ray powder diffractometer. All samples yield the same expansion value α=2.45 (± 0.04) × 10−6 °C at 25 °C. The results of this experiment show that the linear coefficient of thermal expansion of silicon at room temperature is not dependent on its single-crystal state or its powder state.

Thermal Expansion, Magnetic and Electrical Properties of Ternary Compound DyCo0.67Ga1.33

2016 ◽  
Vol 848 ◽  
pp. 703-708
Author(s):  
Liu Qing Liang ◽  
Ling Min Zeng ◽  
Shu Hui Liu ◽  
De Gui Li ◽  
Ming Qin
Keyword(s):  
Electrical Resistivity ◽  
Thermal Expansion ◽  
Ternary Compound ◽  
Coefficient Of Thermal Expansion ◽  
Residual Resistivity ◽  
X Ray Diffraction ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio ◽  
X Ray ◽  
Temperature Range

The ternary compound DyCo0.67Ga1.33 was synthesized and the thermal expansion of DyCo0.67Ga1.33 was studied in the temperature range of 309–608 K by high temperature powder X-ray diffraction technique. The volumetric coefficient of thermal expansion, , can be represented by . Its magnetic properties were measured between 30 and 300 K, and the magnetic susceptibility of DyCo0.67Ga1.33 was found to follow the Curie–Weiss law in the temperature range of 40–300 K. The effective magnetic moment and paramagnetic Curie temperature were estimated to be 9.86 μB and 40.4 K, respectively. Electrical resistivity of the compound DyCo0.67Ga1.33 was also measured between 5 and 300 K. Temperature variation of the electrical resistivity suggests the metallic character of the compound DyCo0.67Ga1.33 with an anomaly detected at 45 K. The residual resistivity ratio RRR of the compound is about 1.2.

Titanium Nitride Epitaxy on Tungsten (100) by Sublimation Crystal Growth

2006 ◽  
Vol 955 ◽  
Author(s):  
Lisa Mercurio ◽  
James H. Edgar ◽  
Li Du ◽  
E. A. Kenik
Keyword(s):  
Thermal Expansion ◽  
Titanium Nitride ◽  
Tensile Strain ◽  
Coefficient Of Thermal Expansion ◽  
Nitride Powder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Backscattering Diffraction ◽  
Unit Cells ◽  
Tungsten Foil

ABSTRACTTitanium nitride crystals were grown from titanium nitride powder on tungsten by the sublimation-recondensation technique. The bright golden TiN crystals displayed a variety of shapes including cubes, truncated tetrahedrons, truncated octahedrons, and tetrahedrons bounded by (111) and (100) crystal planes. The TiN crystals formed regular, repeated patterns within individual W grains that suggested epitaxy. X-ray diffraction and electron backscattering diffraction revealed that the tungsten foil was highly textured with a preferred foil normal of (100) and confirmed that the TiN particles deposited epitaxially with the orientation TiN(100)‖W(100) and TiN[100]‖W[110], that is, the unit cells of the TiN crystals were rotated 45° with respect to the tungsten. Because of its larger coefficient of thermal expansion compared to W, upon cooling from the growth temperature, the TiN crystals were under in-plane tensile strain, causing many of the TiN crystals to crack.

CTEAS: a graphical-user-interface-based program to determine thermal expansion from high-temperature X-ray diffraction

2013 ◽  
Vol 46 (2) ◽  
pp. 550-553 ◽  
Author(s):  
Z.A. Jones ◽  
P. Sarin ◽  
R. P. Haggerty ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensions ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Lattice Constants ◽  
Thermal Expansion Tensor ◽  
Different Temperatures ◽  
Diffraction Patterns

The coefficient of thermal expansion analysis suite (CTEAS) has been developed to calculate and visualize thermal expansion properties of crystalline materials in three dimensions. The software can be used to determine the independent terms of the second-rank thermal expansion tensor usinghklvalues, correspondingdhkllistings and lattice constants obtained from powder X-ray diffraction patterns collected at different temperatures. UsingCTEAS, a researcher can also visualize the anisotropy of this essential material property in three dimensions. In-depth understanding of the thermal expansion of crystalline materials can be a useful tool in understanding the dependence of the thermal properties of materials on temperature when correlated with the crystal structure.

Thermal Expansion of Ca1-xSrxZr4(PO4)6 Ceramics

2018 ◽  
Vol 281 ◽  
pp. 389-394
Author(s):  
Yuan Yuan Song ◽  
Yuan Yuan Zhou ◽  
Yang Wang ◽  
Lan Li ◽  
Fu Tian Liu
Keyword(s):  
Thermal Expansion ◽  
Phase Transitions ◽  
Electron Microscope ◽  
Unit Cell Volume ◽  
Coefficient Of Thermal Expansion ◽  
Coprecipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Condition ◽  
Scanning Electron

Ceramics with the formula Ca1-xSrxZr4(PO4)6 (x=0.4, 0.45, 0.5, 0.55) have been synthesized by coprecipitation method, an. their structures, phase transitions, thermal expansion properties have been studied by differential sanning calorimetry, scanning electron microscope, X-ray diffraction and dilatometer. The results show that Ca1-xSrxZr4(PO4)6 ceramics sintered at 1400°C had good sintering condition. Unit cell volume basically had no change with substitution of Ca by Sr. The coprecipitation method saved energy and time. It was introduced to increase the relative density of Ca0.5Sr0.5Zr4(PO4)6 ceramic. The coefficient of thermal expansion was about 1.447×10-6/°C.

Powder Diffraction and Dilatometric Study of SrFe12O19

2019 ◽  
Vol 946 ◽  
pp. 336-340
Author(s):  
Svetlana A. Gudkova ◽  
Danil A. Uchaev ◽  
D.A. Vinnik
Keyword(s):  
Thermal Expansion ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Coefficient Of Thermal Expansion ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
Spontaneous Crystallization ◽  
X Ray ◽  
Cell Parameters ◽  
Good Agreement

Strontium hexaferrite is a well-known material, due to its application in microelectronics. This paper is devoted to strontium hexaferrite single crystals, obtained by the spontaneous crystallization technique with sodium based flux. SrFe12O19 crystals were grounded, pressed to the tablets, and crystals cell parameters were measured by thermal X-ray diffraction technique. Coefficient of thermal expansion calculated from the X-ray thermal diffraction data is in a good agreement with dilatometric measurements.

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