Abstract

Influence of Internal Structure of Polycrystalline Copper on Its Nonlinear Elastic and Acoustic Properties

A.I.Korobov, A.N.Ekonomov (Department of Acoustics, Faculty of Physics, Moscow State University, Moscow, Russia)

e-mail: akor@att.phys.msu.su

During elastic and plastic deformation (with application of unloading and subsequent loading) the complex research (static, quasistatic and dynamic methods) of mechanical and acoustic properties of copper wires with various initial internal structure is performed. The relation between their microstructure and behaviour of the linear and nonlinear acoustic characteristics is established. The analysis of dependences of static, quasistatic and dynamic nonlinear parameters of the samples on deformation has allowed us to reveal a general criterion for their softening long before the breaking point. Thus, it is revealed that the basic role is played not by the value of the parameter of elastic nonlinearity of a material, but the rate of the absolute change in its value, which occurs during the earliest stages of deformation.

Section : 3