The portevin-le chatelier effects in Cu-Ti, Cu-P and Cu-Si alloys

Abstract

The presence or the absence of the Portevin-Le Chatelier effects in Cu-P, Cu-Ti and Cu-Si alloys were investigated as functions of solute content, temperature and heat treatment. The serrated flows were observed in all the systems but in the Si bearing alloys it appeared at higher solute content and with less height of serration than in the other two. The effect of heat treatment was observed only in Cu-Ti alloys; the P-L effects in 0.5 and 0.75% Ti alloys occurred at lower temperature for annealed specimen than for quenched specimen and in alloys with higher solute content the reverse was true. In Cu-Ti and Cu-Si alloys the minimum temperature above which the P-L effect occurred depended strongly upon solute content. The P-L effect in Cu-Ti alloys occurred at considerably higher temperature than in other copper base alloys. It was concluded that these results were explained more rationally by the cluster theory than the Cottrell theory.