Mechanism of serrated flow in a cast nickel base superalloy

Mechanism of serrated plastic flow in a cast nickel base superalloy was investigated in the temperature range of 25-850 °C by conducting tensile tests employing strain rates of 1 × 10−3, 1 × 10−4 and 1 × 10−5 s−1 and subsequent TEM studies. Shearing of γ′ precipitates by superpartials a/2[1 1 0] bounded by anti- phase boundaries are found to be responsible for the serrated yielding.