Reveal the stacking fault shearing mechanism by its annihilation process in Ni-based single crystal superalloys

Based on the reversibility of stacking fault formation, the annihilation process during annealing was characterized to reveal the stacking fault shearing mechanism in Ni-based single crystal superalloys. After the creep rupture test at 750 °C/750 MPa, lots of stacking faults would be created in γ' precipitates. Further annealing at 1000 °C for 4 h, these stacking faults would shrink and were transformed into dislocation pairs containing two a/2 〈110〉 dislocation with different Burgers vectors. Finally, the stacking fault shearing mechanism could be clarified as:a/21¯01+a/201¯1→a/31¯1¯2+SF+a/61¯1¯2.