J. Phys. Colloques
Volume 48, Numéro C8, Décembre 1987Fifth European Conference on Internal Friction and Ultrasonic Attenuation in Solids
|Page(s)||C8-131 - C8-135|
J. Phys. Colloques 48 (1987) C8-131-C8-135
THE BORDONI PEAK IN ALUMINIUM SINGLE CRYSTALS AT MHz FREQUENCIESM. ZEIN
Physics Department, University of Bahrain, College of Arts, Science and Education, PO Box 1082, Bahrain
The Bordoni peak in high purity aluminium single crystals has been investigated by measuring the attenuation of longitudinal waves at 10 MHz, using a conventional ultrasonic pulse echo technique with a single quartz transducer. The crystals, of <100>, <110> and <111> orientation, were deformed by compression, and the temperature dependence of the ultrasonic attenuation was measured after applying resolved shear stresses ranging up to 60 Nmm-2. The results lead to the following conclusions: (i) the temperature of the Bordoni peak in aluminium single crystals is essentially independent of the orientation ; (ii) the temperature of the peak decreases considerably as the prior deformation was increased up to a resolved shear stress near 28 Nmm-2, and then increases slightly for higher prior stresses, (iii) the peak height increases with increasing deformation and, (iv) the subsidiary peak appears only at low deformation.