A MODEL FOR THE OCCURRENCE OF SERRATED YIELDING IN SUBSTITUTIONAL ALLOYS

<正> On account of the integral behavior of dislocations and the interaction between solute atoms and dislocations, a model describing the serrated yielding (i.e. the PL effect) in substitutional alloys is proposed. According to this model, the serrated yielding occurring in a certain strain rate-temperature range will disappear when the strain exceeds a proper value under certain conditions. The model has been confirmed by tensile tests and rapid changing strain rate tests on a commercial Cu-32wt.％ Zn alloy. Experimental results agree well with the predicted effects of temperature and strain rate on the critical strain for the appearance and disappearance of serrations.