J. Phys. IV France
Volume 124, Mai 2005
Page(s) 341 - 345

J. Phys. IV France 124 (2005) 341-345

DOI: 10.1051/jp4:2005124050

Elastic constants determination using the velocity of only one propagating mode: $V_{\rm L}$, $V_{\rm T}$ or $V_{\rm R}$

M. Doghmane1, 2, I. Hadjoub2, A. Doghmane2 and F. Hadjoub2

1  Département de Physique, Faculté des Sciences, Université de Guelma, Algeria
2  Laboratoire des Semi-Conducteurs, Département de Physique, Faculté des Sciences, Université Badji-Mokhtar, BP. 12, 23000 Annaba, Algeria,

In nondestructive micro-characterization, elastic constants are generally expressed in terms of velocities of longitudinal waves, V$_{\rm L}$, and transverse waves, V$_{\rm T}$. However, it is often difficult to determine these velocities by a single measurement. In this context, we propose the derivation of new expressions according to only one parameter: V$_{\rm L}$, V$_{\rm T}$ or Rayleigh velocity, V$_{\rm R}$. Thus, by using Viktorov formula and certain acceptable physically approximations, deduced, for any material of density $\rho$ the following relations: E = 0.757 $\rho {{\rm V}_{\rm L}}^{2}$, E = 2.586 $\rho {{\rm V}_{\rm T}}^{2}$, E = 2.99 $\rho {{\rm V}_{\rm R}}^{2}$, G = 0.293 $\rho {{\rm V}_{\rm L}}^{2}$ and G = 1.156 $\rho {{\rm V}_{\rm R}}^{2}$.The validity of these relations is put into evidence for a large number of materials (Al, Cd, Fe, Mg, Mo, Ti, W, Pt, Ni, etc) characterized by fast, medium or slow velocities. Excellent precisions of 0.007 % and 0.009 % were obtained respectively for G = f(V$_{\rm L})$ with Mo and for E = f(V$_{\rm T})$ with Fe. These very encouraging results find their applications in acoustic microscopy into which only one surface mode often dominates the acoustic materials signatures, V(z).

© EDP Sciences 2005