Investigation of changes in the type B PLC effect of Al–Mg–Cu type alloy for various strain rates

The Portevin–LeChatelier (PLC) effect exemplifies itself as continuous stress changes during the tensile deformation of particular alloys. The PLC effect takes several forms, which differ significantly in both the spatial distribution of strain bands and in the shape of the stress–strain curve. The courses corresponding to particular serration types are characterized by different properties of the signal energy distribution, depending on the conditions under which the tensile process is carried out, as well as on the parameters connected with metallurgical processing of the material. It was also found that the energy distribution depends on the instantaneous value of strain/stress, which justifies the application of time–frequency analysis methods to obtain the detailed spectral characteristics of the Portevin–LeChatelier effect.