Abstract
Serrated yielding was clearly observed between 330 and 460°C at a strain rate of 2.22×10−4 sec−1 in Ti-2 at%Zr alloy, while in a commercially pure titanium it was not so clear. Two types of serrations were observed in the alloy. One type is the serrations with a regular periodicity and the other is the serrations with relatively large stress drops which occur intermittently. In cases where the strain increases, the strain rate decreases or the grain size decreases, the stress amplitude of the regular serrations increases. Examination of the temperature and strain rate dependence of the regular serrations suggests that serrated yielding in Ti-2 at%Zr alloy is probably dominated by the diffusion of both zirconium and interstitial impurity atoms. The regular serrations, therefore, must be closely related to the strong interaction between a dislocation and an interstitial impurity atom which is at the octahedral site distorted locally by a zirconium atom.
