Search

The theoretical assessment of mechanical and elastic properties is used to analyze the distinctive properties of high entropy alloys (HEAs) at room temperature. Using Lennard–Jones potential model, the second order elastic constants (SOECs) and third order elastic constants (TOECs) have been determined for the HEAs Hf0.25Ti0.25Zr0.25Sc0.25−xAlx (x ≤ 15 %) in their hexagonal close-packed (hcp) phases. SOECs have been used to calculate mechanical constants, Poisson's ratio, Pugh's ratio, Kleinman's parameter. In order to determine the anisotropic behaviour of the selected HEAs, the elastic anisotropy has also been computed at room temperature. All the HEAs under consideration have anisotropy parameters that are not equal to one, indicating anisotropic behaviour. Later, the Grüneisen parameters were estimated for the chosen HEAs Hf0.25Ti0.25Zr0.25Sc0.25−xAlx (x ≤ 15 %) along longitudinal and shear modes of wave propagation. Analysis of the research results reveals the inherent properties of HEAs. [ABSTRACT FROM AUTHOR]

The ultrasonic attenuation studies of alkali halides single crystal AX (A = Li, Na, K and X = F, Cl, Br) have been investigated along <100>, <110> and <111> directions at room temperature. For this investigation, a most appropriate potential model for studying physical studies of rock-salt type alkali halides, the Coulomb and Born–Mayer model has been used to evaluate higher order elastic constants. The second order elastic constants are used to compute the mechanical properties and ultrasonic velocities of the chosen materials. Additionally, the thermal properties have also been evaluated along different orientations. Thermoelastic loss is very small in comparison to the attenuation due to phonon-phonon interaction mechanism at room temperature. The achieved results of AX have been discussed and compared with available experimental and theoretical results. [ABSTRACT FROM AUTHOR]

The acoustic coupling constant D, is related to the change in elastic modulus caused by strain: HT ht Graph (16)Where HT ht and HT ht are square average and average square Grüneisen parameters, respectively. [Extracted from the article]

The elastic and ultrasonic properties have been evaluated at room temperature between the pressure 0.6 and 10.4 GPa for hexagonal closed packed (hcp) hafnium (Hf) metal. The Lennard-Jones potential model has been used to compute the second and third order elastic constants for Hf. The elastic constants have been utilized to calculate the mechanical constants such as Young's modulus, bulk modulus, shear modulus, Poisson's ratio, and Zener anisotropy factor for finding the stability and durability of hcp hafnium metal within the chosen pressure range. The second order elastic constants were also used to compute the ultrasonic velocities along unique axis at different angles for the given pressure range. Further thermophysical properties such as specific heat per unit volume and energy density have been estimated at different pressures. Additionally, ultrasonic Grüneisen parameters and acoustic coupling constants have been found out at room temperature. Finally, the ultrasonic attenuation due to phonon–phonon interaction and thermoelastic mechanisms has been investigated for the chosen hafnium metal. The obtained results have been discussed in correlation with available findings for similar types of hcp metals. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Naturforschung Section A: A Journal of Physical Sciences is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Naturforschung Section A: A Journal of Physical Sciences is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present article comprises computation of elastic, ultrasonic, and thermo-physical properties of RM (R = Tb, Dy, Ho, Er, Tm; M = Zn, Cu) compounds at 300 K. The second-order elastic constants (SOECs) and elastic moduli are evaluated initially, using potential model approach considering interaction up to second nearest neighbours. The ultrasonic velocities are obtained for wave propagation along <100>, <110>, and <111> crystallographic directions using evaluated SOECs. The Debye temperature, specific heat at constant volume, thermal energy density, thermal conductivity, and thermal relaxation time are also calculated. The obtained results are compared and analysed for justification and application of materials. [ABSTRACT FROM AUTHOR]