Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. IV France 06 (1996) C8-783-C8-786
Amplitude-Dependent Internal Friction and Microplasticity in Thin-Film MaterialsY. Nishino and S. Asano
Department of Materials Science and Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya 466, Japan
Internal friction in aluminum thin films on silicon substrates has been measured between 180 and 360 K as a function of strain amplitude. The amplitude dependence of internal friction in the aluminum films has been evaluated from the data on the film-substrate composite and further converted into the plastic strain of the order of 10-9 as a function of the effective stress on dislocation motion. The microplastic stress-strain curves thus obtained for the aluminum films tend to shift to a higher stress with decreasing film thickness and also with decreasing temperature. It is concluded that the microflow stress at a constant level of the plastic strain varies inversely with the film thickness at all the temperatures examined.
© EDP Sciences 1996