Ultrasonic investigations in intermetallics

Abstract

Ultrasonic attenuation for the longitudinal and shear waves due to phononphonon interaction and thermoelastic mechanism have been evaluated in B2 structured intermetallic compounds AgMg, CuZr, AuMg, AuTi, AuMn, AuZn and AuCd along 1 0 0 , 1 1 1 and 1 1 0 crystallographic directions at room temperature. For the same evaluations, second-and third-order elastic constants, ultrasonic velocities, Grüneisen parameters, non-linearity parameter, Debye temperature and thermal relaxation time are also computed. Although the molecular weight of these materials increases from AgMg to AuCd, the obtained results are affected with the deviation number. Attenuation of ultrasonic waves due to phonon-phonon interaction is predominant over thermoelastic loss. Results are compared with available theoretical and experimental results. The results with other well-known physical properties are useful for industrial purposes.

Temperature Dependent Elastic and Ultrasonic Properties of Iron Aluminide

“…This nature is very similar to other investigations on cubic crystals [32][33][34][35]36]. The order of ultrasonic velocities for longitudinal and shear waves is found same as our previous study on intermetallics [31]. Figure . 1 also shows that the order of thermal relaxation time (τ th ) for FeAl is 10-13 second, which is same as in other intermetallics [31][32][33][34].this signifies that the circulation of thermal phonon maintain its equilibrium location in 10 -13 s after passing the ultrasonic wave.…”

“…The order of ultrasonic velocities for longitudinal and shear waves is found same as our previous study on intermetallics [31]. Figure . 1 also shows that the order of thermal relaxation time (τ th ) for FeAl is 10-13 second, which is same as in other intermetallics [31][32][33][34].this signifies that the circulation of thermal phonon maintain its equilibrium location in 10 -13 s after passing the ultrasonic wave. Although this is less time than the other metallic alloys [15].SOEC and TOEC are used to obtain average ultrasonic Grüneisen parameters (UGP) along <100> direction for longitudinal wave over 39 modes and for shear wave 18 modes.…”

Sensitivity of Nanostructured Iron Metal on Ultrasonic Properties

“…The secondary objective of the present investigation is to develop a theory for evaluation of ultrasonic attenuation. Mason-Bateman Theory [11,14,15,[19][20][21][22][23][24][25][26][27] is still widely used successfully to study the ultrasonic attenuation at higher temperature (300 K) in solids. It is more reliable theory to study anharmonicity of the crystals as it involves elastic constants directly through acoustic coupling constant "D" in the evaluation of ultrasonic attenuation (α).…”

“…A number of books and review articles are available which gives experimental techniques and theoretical interpretation. In solids [10,11] there are several causes of ultrasonic attenuation, the most important being electron-phonon interaction at low temperatures [12,13] and phonon-phonon interaction at high temperatures [14,15]. There are several methods for theoretical evaluation of ultrasonic attenuation, but the most accepted and reliable one uses second and third order elastic constants (SOEC and TOEC) [10,11].…”