Numéro
J. Phys. Colloques
Volume 42, Numéro C5, Octobre 1981
ICIFUAS-7
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
Page(s) C5-1141 - C5-1146
DOI https://doi.org/10.1051/jphyscol:19815176
ICIFUAS-7
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids

J. Phys. Colloques 42 (1981) C5-1141-C5-1146

DOI: 10.1051/jphyscol:19815176

A NEW TECHNIQUE OF MEASUREMENT BY COUPLING OF A CYCLIC LOW FREQUENCY STRESS WITH AN ULTRASONIC WAVE

G. Gremaud

Institut de génie atomique, Swiss Federal Institute of Technology, 1015 Lausanne, Switzerland


Abstract
By measurement of the low frequency internal friction spectrum, the different mechanisms which control the dislocation mobility, present very similar peaks. In the same way the microdeformation curves measured by the ultrasonic methods do not present great differences between different mechanisms. To avoid this indetermination on the mechanisms, a new technique has been developed (1). It consists in measuring the attenuation Ɗα and the relative change Ɗt/t of propagation time of ultrasonic waves in a sample, with a permanent sinusoidal low frequency applied stress (σ). Curves Ɗα(σ) and Ɗt/t(σ), each one measured during one cycle of the stress, are drawn as a function of time or temperature. These curves present different shapes and different evolutions depending on the involved mechanism. Some experimental results obtained by this technique are presented at this conference in two other papers (2, 3). In this paper, the measuring device will be presented.