Elastic constants of single crystal γ – TiAl

1995 ◽  
Vol 10 (5) ◽  
pp. 1187-1195 ◽  
Author(s):  
Y. He ◽  
R.B. Schwarz ◽  
A. Migliori ◽  
S.H. Whang
Keyword(s):  
Single Crystal ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Theoretical Calculations ◽  
Elastic Stiffness ◽  
Orientation Dependence ◽  
Polycrystalline Materials ◽  
Ultrasonic Spectroscopy ◽  
First Time ◽  
Good Agreement

The six independent second-order elastic stiffness coefficients of a Ti44Al56 single crystal (L10 structure) have been measured at room temperature for the first time using a resonant ultrasonic spectroscopy (RUS) technique. These data were used to calculate the orientation dependence of Young's modulus and the shear modulus. Young's modulus is found to reach a maximum near a [111] direction, close to the normal to the most densely packed planes. The elastic moduli and Poisson's ratio for polycrystalline materials, calculated by the averaging scheme proposed by Hill, are in good agreement with experimental data and theoretical calculations.

Effect of Phase Stability on Some Physical and Mechanical Properties in β-Ti Single Crystal for Biomedical Applications

2014 ◽  
Vol 783-786 ◽  
pp. 1372-1376 ◽  
Author(s):  
Mitsuharu Todai ◽  
Pan Wang ◽  
Keisuke Fukunaga ◽  
Takayoshi Nakano
Keyword(s):  
Physical Properties ◽  
Single Crystal ◽  
Young’S Modulus ◽  
Phase Stability ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
Elastic Stiffness ◽  
Alloy Single Crystal ◽  
Β Phase ◽  
Ti Alloys

The electron-atom ratio (e/a) dependence of the appearance of the lattice modulation and physical properties in β-phase Ti-xNb alloys (x= 28, 30, 34 and 40) were investigated by using some physical properties measurements, compressive test and transmission electron microscope observations (TEM observations), focusing on the β-phase stability. The microstructure, physical properties, deformation mode depend on thee/aratio which is closely related to the β-phase stability in Ti-Nb alloys. Thee/aratio is defined by the average electrons per atom in free atom configuration. Athermal ω-phase is suppressed in Ti-30Nb alloy single crystal with lowe/aratio. The Ti-30Nb alloy single crystal also exhibits a lattice modulation and low Debye temperature. These results imply that the β-phase stability in β-phase Ti alloys decreases with decreasing thee/aratio and are related to the softening of elastic stiffness,c′. Consequently, a decrease in thee/aratio leads to the softening ofc′ and a significant reduction in modulus along the [100] direction in β-phase Ti alloys single crystal. In fact, the Young’s modulus along [100] of the Ti-15Mo-5Zr-3Al alloy (wt.%) single crystal with lowe/aratio exhibits as low as 45 GPa, which is comparable to that the human cortical bone. That is, controlling thee/aratio is an ultimate strategy to develop the future superior biocompatible implant materials with extremely low Young’s modulus and good deformability.

Significant reduction in Young's modulus of Fe–Ga alloy single crystal by inverse magnetostrictive effect under tensile stress

2018 ◽  
Vol 124 (23) ◽  
pp. 233901 ◽  
Author(s):  
S. Fujieda ◽  
S. Asano ◽  
S. Hashi ◽  
K. Ishiyama ◽  
T. Fukuda ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Single Crystal ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Alloy Single Crystal

Indirect Coupling Constants in a Thallium Single Crystal

1974 ◽  
Vol 52 (8) ◽  
pp. 687-693
Author(s):  
J. Schratter ◽  
D. Llewelyn Williams
Keyword(s):  
Single Crystal ◽  
Angular Dependence ◽  
Line Width ◽  
Orientation Dependence ◽  
Coupling Constants ◽  
Second Moment ◽  
Indirect Coupling ◽  
First Time

We have measured the angular dependence of the line width in thallium and related it to the second moment to estimate the pseudodipolar and pseudoexchange contributions for the first two shells of neighbors. These values are very different, despite the fact that both shells have nearly the same radius, and this establishes experimentally for the first time an orientation dependence of the indirect coupling constants.

scholarly journals Studies on Structure and Elasto-Mechanical Properties of Suvin Cotton Fibre

2020 ◽  
Vol 12 (4) ◽  
pp. 607-620
Author(s):  
V. V. Manju ◽  
S. Divakara ◽  
R. Somashekar
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Web Application ◽  
Young's Modulus ◽  
Least Square Method ◽  
Elastic Stiffness ◽  
Cotton Fibre ◽  
Least Square ◽  
3 Dimensional

The comprehensive elastic properties of Suvin cotton fibre have been estimated. The Linked Atom Least Square method (LALS) technique has been employed to compute the structural properties using the X-ray diffraction data. Using Treloar’s assumptions the elastic stiffness matrix |Cij| has been calculated, then by utilizing the Voigt theory the elastic constants like Young’s modulus (E), Bulk modulus (K), Shear modulus (G), Poisson’s ratio (ν) and linear compressibility (β) have been estimated. Further, the experimental results of elastic constants are obtained and compared with the computed results and a broad correlation between them has been observed. ELATE web application tool is used to obtain the 3-dimensional images of variation of elastic constants along their spatial axes. From these figures an attempt has been made to explain the anisotropic mechanical property with respect to directional dependent Young’s modulus (E) and Shear modulus properties (G).

scholarly journals Influence of three-dimensional nanoparticle branching on the Young’s modulus of nanocomposites: Effect of interface orientation

2015 ◽  
Vol 112 (21) ◽  
pp. 6533-6538 ◽  
Author(s):  
Shilpa N. Raja ◽  
Andrew C. K. Olson ◽  
Aditya Limaye ◽  
Kari Thorkelsson ◽  
Andrew Luong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Elastic Stiffness ◽  
Limited Attention ◽  
Unexpected Finding ◽  
Covalent Bonds ◽  
Lattice Spring Model ◽  
Common Block

With the availability of nanoparticles with controlled size and shape, there has been renewed interest in the mechanical properties of polymer/nanoparticle blends. Despite the large number of theoretical studies, the effect of branching for nanofillers tens of nanometers in size on the elastic stiffness of these composite materials has received limited attention. Here, we examine the Young's modulus of nanocomposites based on a common block copolymer (BCP) blended with linear nanorods and nanoscale tetrapod Quantum Dots (tQDs), in electrospun fibers and thin films. We use a phenomenological lattice spring model (LSM) as a guide in understanding the changes in the Young's modulus of such composites as a function of filler shape. Reasonable agreement is achieved between the LSM and the experimental results for both nanoparticle shapes—with only a few key physical assumptions in both films and fibers—providing insight into the design of new nanocomposites and assisting in the development of a qualitative mechanistic understanding of their properties. The tQDs impart the greatest improvements, enhancing the Young's modulus by a factor of 2.5 at 20 wt.%. This is 1.5 times higher than identical composites containing nanorods. An unexpected finding from the simulations is that both the orientation of the nanoscale filler and the orientation of X-type covalent bonds at the nanoparticle-ligand interface are important for optimizing the mechanical properties of the nanocomposites. The tQD provides an orientational optimization of the interfacial and filler bonds arising from its three-dimensional branched shape unseen before in nanocomposites with inorganic nanofillers.

Spectroscopic Investigation of V3+:YAG Crystal

2013 ◽  
Vol 774-776 ◽  
pp. 811-815 ◽  
Author(s):  
Jian Ma
Keyword(s):  
Room Temperature ◽  
Factor Model ◽  
Theoretical Calculations ◽  
Czochralski Method ◽  
Experiment Data ◽  
Crystal Field Theory ◽  
Calculation Results ◽  
First Time ◽  
Pure Argon Atmosphere ◽  
Good Agreement

V3+ions doped YAG crystals were grown using the Czochralski method in a highly pure argon atmosphere. The transmission spectrum of trivalent vanadium in YAG crystal has been measured at room temperature. Eight bands were observed in which two bands centered at 690nm (14493cm-1) and 1490nm (6711cm-1) are reported for the first time. By using the crystal-field theory and introducing the average covalent factor model, we also presented the theoretical calculations of the energy level splitting of tetrahedrally coordinated V3+impurity systems in YAG crystal. These calculation results are in good agreement with the optical experiment data.

The Initial Modulus of Filament Webs

1980 ◽  
Vol 102 (4) ◽  
pp. 360-365
Author(s):  
R. W. Dent
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Bond Rotation ◽  
Initial Modulus ◽  
Continuous Filament ◽  
First Time

A review of the existing theories for the Young’s modulus of continuous filament random webs is given. It is shown that the effect of buckling of the transverse filaments must be included in the theory. This means that filament bending and bond rotation must also be included in the model for the theory to be consistent. Accordingly, we have derived a theory including the effects of buckling, filament bending and bond rotation for the first time and the results are given and compared to those obtained where buckling was neglected.

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