2002 Volume 66 Issue 3 Pages 127-130
Effects of Be, Cu and Ag as microalloying elements on age hardening and two-step aging behavior of an Al-1.3 mass%Mg2Si alloy have been investigated by hardness measurement, electrical resistivity measurement, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). These microalloying elements markedly increase both the hardening rate and peak hardness in artificial aging at 453 K. Their effects on two-step aging, however, much differ from each other. Negative and positive effects of two-step aging are reduced by Cu addition. On the contrary, negative effect is increased and positive effect turns into negative by Ag addition. The complex cluster formation model was proposed to explain the effects of microalloying elements.
