Preliminary Time Series Analysis of Serrated Yielding in Al-4%Cu Alloy
Al-4%Cu多晶合金中锯齿形屈服现象的初步时序分析

A systematic statistical analysis of the characteristics of the Portevin-Le Chartelier (PLC) effect in Al-4%Cu alloy, including the stress drop amplitude and the reloading time, etc., is carried out. The drop duration is found to be a constant independent of the strain. The average stress drop amplitude and the average reloading time of 1 and 2 mm thick samples increase with strain linearly, while the cases of 3 mm thick samples are much more complicated. The evidence of self-organized criticality is demonstrated, and the nonlinear mechanism in the PLC effect is also explained by comparing with the classic sand-pile model, and by combining with the dynamic strain aging (DSA) principle and the dislocation dynamics.