PLC Effect at Different Types of Loading During Static Tensile Testing of Aluminium Alloys

Abstract

Aluminium and aluminium alloys are indispensable materials nowadays, widely used in various constructions. It is known that some aluminium alloys, such as Al-Mg, show inhomogeneous, localized deformation phenomena at certain temperatures and strain rates. This is known in the literature as the appearance of Portevin-Le Chatelier lines, or short the PLCeffect. The Portevin-Le Chatelier effect contributes to the reduction of material ductility and leaves surface defects on the final products. The study of this phenomenon was carried out using a static tensile test and the digital image correlation method. The influence of using a constant increase of stress on the phenomenon itself was studied in comparison to the classical control of the testing machine with a constant crosshead speed. The results of the study show that the phenomenon persists regardless of the type of control and no significant changes were observed at used testing parameters. Regardless of the deformation parameters, PLC lines form throughout the whole duration of the plastic deformation until the specimen breaks.