Thermal observations associated with the Portevin-Le Châtelier effect in an Al-Mg alloy

This paper presents an experimental investigation on temperature variations associated with the Portevin-Le Châtelier (PLC) effect. Using thermal fields, this work was aimed at gaining further insight into the spatio-temporal distribution of PLC bands. A fast multidetector infrared camera was used for the observations, in a room temperature tensile test conducted at constant strain rate. As the thermal diffusivity of the aluminum alloy is very high, the measured temperature variations were quite low and very diffuse. The associated heat sources were calculated in order to increase the precision of PLC band detections. These fields revealed localized dissipative bands oriented according to the loading direction. They were classified as type A or B according to their spatio-temporal distribution. Then, various band characteristics were determined: shape, width, orientation, propagation direction, changes of orientation, band propagation velocity, duration and period.