Investigation of the effect of electric current on serrated deformation and acoustic emission in the aluminum-magnesium alloy 5056

Abstract

The effect of direct electric current on the serrated deformation of the aluminum-magnesium alloy 5056 has been studied using the acoustic emission method and high speed video filming of propagating deformation bands. The phenomenon of the electric current induced suppression of low frequency acoustic emission signals has been revealed in the range of 1 Hz-2 kHz, which is connected with the development of Portevin-Le Chatelier deformation bands. The characteristic times of damping and growth of plastic insta bilities and acoustic signals caused by them after current turn on and turn off, respectively, have been esti mated.