Strain rate dependence of the yield stress and strain hardening rate of a single crystal superalloy at intermediate temperature

The effect of temperature and strain rate on the yield stress and deformation mechanism of the DD6 single crystal is investigated. The results show that the strain rate has very limited effect on the yield stress and strain hardening rate at 873 K, but has strong effect on both properties at 1073 K. The situation at 873 K is similar with the single phase gamma'. At 1073 K, the strong strain rate dependence of yield stress is due to the operation of stalking faults. The strain rate dependence of strain hardening rate at 1073 K is attributed to the difference of the dislocation density in the matrix channels. (C) 2014 Elsevier B.V. All rights reserved.