scholarly journals Elastic Properties of Polycrystals: A Review

1990 ◽  
Vol 12 (1-3) ◽  
pp. 1-14 ◽  
Author(s):  
S. Hirsekorn
Keyword(s):  
Single Crystal ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Polycrystalline Materials ◽  
Effective Elastic Constants ◽  
Structure Properties

The elastic properties of polycrystals depend on the single-crystal elastic constants of the crystallites which build up the polycrystal and on the manner in which the crystallites are connected. Because of the technical importance of polycrystalline materials a lot of papers deal with the problem to calculate effective elastic constants of polycrystals from single-crystal and structure properties. This paper gives a review concerning the most important theories and methods respecting this matter.

Residual Stress Measurement of Silicon Nitride and Silicon Carbide by X-Ray Diffraction Using Gaussian Curve Method

1988 ◽  
Vol 32 ◽  
pp. 459-469 ◽  
Author(s):  
Masanori Kurita ◽  
Ikuo Ihara ◽  
Nobuyuki Ono
Keyword(s):  
Residual Stress ◽  
Single Crystal ◽  
Elastic Constants ◽  
Stress Measurement ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Areas ◽  
Curve Method ◽  
The Continuum

The residual stress induced by grinding or some thermal treatment has a large effect on the strength of ceramics. The X-ray technique can be used to nondestructively measure the residual stress in small areas on the surface of polycrystalline materials. The X-ray stress measurement is based on. the continuum mechanics for macroscopically isotropic polycrystalline materials. In this method, the stress value is calculated selectively from strains of a particular diffraction plane in the grains which are favorably oriented for the diffraction. In general, however, the elastic constants of a single crystal depend on the plane of the lattice, since a single crystal is anisotropic, The behavior of the deformation of individual crystals in the aggregate of polycrystalline materials under applied stress has not yet been solved successfully. Therefore, the stress constant and elastic constants for a particular diffracting plane should be determined experimentally in order to determine the residual stress accurately by X-ray diffraction.

Effective elastic constants and acoustic properties of single-crystal TiN/NbN superlattices

1992 ◽  
Vol 7 (8) ◽  
pp. 2248-2256 ◽  
Author(s):  
Jin O. Kim ◽  
Jan D. Achenbach ◽  
Meenam Shinn ◽  
Scott A. Barnett
Keyword(s):  
Single Crystal ◽  
Elastic Constants ◽  
Acoustic Waves ◽  
Mass Density ◽  
Surface Acoustic Waves ◽  
Dispersion Curves ◽  
Acoustic Properties ◽  
Tetragonal Symmetry ◽  
Cubic Symmetry ◽  
Effective Elastic Constants

Using the measured elastic constants of TiN and NbN single crystals with cubic symmetry, the effective elastic constants of single-crystal TiN/NbN superlattice films with tetragonal symmetry, namely c11, c12, c13, c33, c44, and c66 have been calculated for various thickness ratios of the layers. Using a line-focus acoustic microscope, measurements of surface acoustic waves (SAWs) have been carried out on single-crystal TiN/NbN superlattice films grown on the (001) plane of cubic crystal MgO substrates. The phase velocities measured as functions of the angle of propagation display the expected anisotropic nature of cubic crystals. Dispersion curves of SAWs propagating along the symmetry axes have been obtained by measuring wave velocities for various film thicknesses and frequencies. The SAW dispersion curves calculated from the effectiveelastic constants and the effective mass density of the superlattice films show very good agreement with experimental results. The results of this paper exhibit no anomalous dependence of the elastic constants on the superlattice period of TiN/NbN superlattices.

Elastic Properties of L10-Ordered Single Crystals

2007 ◽  
Vol 26-28 ◽  
pp. 221-224 ◽  
Author(s):  
C. Wang ◽  
Katsushi Tanaka ◽  
Kyosuke Kishida ◽  
Haruyuki Inui
Keyword(s):  
Single Crystal ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Elastic Anisotropy ◽  
Axial Ratio ◽  
Spectroscopy Technique ◽  
Complete Set

The temperature dependence of single-crystal elastic constants of L10-ordered single-crystals of FePd . A complete set of elastic constants has been determined with the resonance ultrasound spectroscopy technique. The compounds clearly show a tetragonal elastic anisotropy, c11 < c33 and c44 < c66. The temperature dependencies of the anisotropies are not simply explained by the variation of axial ratio (c/a) of the crystal.

scholarly journals Calculation of Linear and Non-Linear Elastic Properties of Polycrystalline Materials by Use of a Cluster Model

1997 ◽  
Vol 28 (3-4) ◽  
pp. 261-271 ◽  
Author(s):  
H. Kiewel ◽  
H. J. Bunge ◽  
L. Fritsche
Keyword(s):  
Elastic Properties ◽  
Grain Shape ◽  
Cluster Method ◽  
Elastic Behavior ◽  
Polycrystalline Materials ◽  
Linear Elastic ◽  
Effective Elastic Constants ◽  
Real Material ◽  
Non Linear ◽  
Effective Constants

In the present paper we have put together some results of a cluster method that allows the calculation of linear and also non-linear effective elastic constants of polycrystalline materials within an iterative self-consistent scheme. The conceptual idea consists in simulating the real material by a suitably chosen cluster of single grains. One can then determine the elastic properties of the material under study by examining the elastic behavior of the cluster. The method is capable of resolving the effect of the grain shape, that is determined by the coordination number of the grains on the effective constants.

scholarly journals Investigation of Elastic Properties of the Single-Crystal Nickel-Base Superalloy CMSX-4 in the Temperature Interval between Room Temperature and 1300 °C

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 152
Author(s):  
Alexander Epishin ◽  
Bernard Fedelich ◽  
Monika Finn ◽  
Georgia Künecke ◽  
Birgit Rehmer ◽  
...  
Keyword(s):  
Single Crystal ◽  
Elastic Properties ◽  
Temperature Interval ◽  
Elastic Constants ◽  
Gas Turbines ◽  
Room Temperature ◽  
Nickel Base Superalloy ◽  
Resonance Frequencies ◽  
Nickel Base ◽  
Base Superalloy

The elastic properties of the single-crystal nickel-base superalloy CMSX-4 used as a blade material in gas turbines were investigated by the sonic resonance method in the temperature interval between room temperature and 1300 °C. Elastic constants at such high temperatures are needed to model the mechanical behavior of blade material during manufacturing (hot isostatic pressing) as well as during technical accidents which may happen in service (overheating). High reliability of the results was achieved using specimens of different crystallographic orientations, exciting various vibration modes as well as precise measurement of the material density and thermal expansion required for modeling the resonance frequencies by finite element method. Combining the results measured in this work and literature data the elastic constants of the γ- and γ′-phases were predicted. This prediction was supported by measurement of the temperature dependence of the γ′-fraction. All data obtained in this work are given in numerical or analytical forms and can be easily used for different scientific and engineering calculations.

Structural and Elastic Properties of HF/ZR Multilayer Thin Films

1990 ◽  
Vol 187 ◽  
Author(s):  
W. J. Meng ◽  
G. L. Eesley ◽  
K. Svinarich ◽  
G. P. Meisner
Keyword(s):  
Thin Films ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
Deposition Rates ◽  
X Ray ◽  
Effective Elastic Constants

AbstractWe have investigated structural and elastic properties of Hf/Zr multilayer thin films by x-ray diffraction and transient piezoreflectance measurements. Similar structural and elastic behaviors have been observed in two series of samples grown at different deposition rates (1 – 10Å/sec). Our measurements suggest different (˜ 10%) effective elastic constants between multilayers with coherent and incoherent interfaces.

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