Portevin-Le Chatelier Effect and Mechanical Properties of 5A01 Aluminum Alloy

Differential scanning calorimetry(DSC),microstructure observation,tensile test at room temperature and transmission electron microscopy(TEM) were used to study the microstructure,Portevin-Le Chatelier(PLC) effect and mechanical properties under different strain rates for 5A01(6.13wt%Mg) aluminum alloy.The results show that β-phase precipitated out from the as-quenched alloy,the alloy aged at 150℃ or at 350℃ for 1h,in which the amount of β-phase in the alloy aged at 150 ℃ for 1h is the highest.And with increasing the aging time(1-72h),the PLC effect of the alloy aged at 150 ℃ is weakened.With increasing the aging temperature from 150℃ to 350℃,the PLC effect of the alloy aged for 1h is strengthened.In addition,when the strain rate is 6.66×10～(-4)s～(-1),ultimate tensile strength(UTS) and elongation strain of the tested samples do not have obvious change;but when the strain rate is down to 8×10～(-5)s～(-1),UTS and elongation strain of the alloy aged at 150℃/1h are the highest and the lowest,respectively.The mechanism of PLC effect and changes of mechanical properties for 5A01 aluminum alloy can be explained by the interaction between Mg atoms and dislocations.