Initiation and Suppression of the Portevin–Le Chatelier Effect in Aluminum Alloy under IR Laser Irradiation and Electric Current

Abstract

The separate and joint effect of IR laser irradiation and electric current on the Portevin–Le Chatelier effect and generation of deformation bands in aluminum–magnesium alloy AlMg6 has been investigated in situ by complex methods, including acoustic emission (AE) and high-speed video recording. The nucleation and evolution of the deformation bands initiated by pulsed laser radiation focused on the surface of deformed sample have been investigated with the time resolution up to 0.1 ms. The conditions under which a single laser “puncture” with a duration of up to ~1 ms initiates discontinuous deformation during several tens of seconds and reduces significantly (by a factor of 1.5) the critical strain of the onset of Portevin–Le Chatelier effect in AlMg6 alloy are revealed. It is established that transmission of low-density (below 40 А/mm2) direct electric current suppresses the negative influence of laser irradiation and completely stabilizes the deformation behavior of the alloy. Possible applications of the obtained results are discussed.