On the formation and motion of 〈010〉 — dislocations during high temperature low stress creep of superalloy single crystals

The cutting of γʹ-particles by dislocations during shear creep of superalloy single crystals loaded on the shear system 〈110〉111 at T = 1025 °C and τ = 85 MPa is analysed. It was found that two γ-matrix channel dislocations with different Burgers vectors of type a0/2〈110〉 jointly shear the γ′-particle and compose a superdislocation with a Burgers vector of a0〈010〉. Peach-Koehler forces were calculated which are associated with the birth of these superdislocations. The results of the numerical study show that the formation of 〈010〉 dislocations in the superalloy microstructure is energetically favourable.