Effect of crystal structure on dislocation arrays in aging alloys during active deformation

1. In alloys with moderate amounts of γ′ phase (KhN67MVTYu and KhN60MVTYu) with particle sizes of 350–700 A the combination of high strength and ductility is due to the mechanism of particles being cut by individual moving superdislocations. The higher yield strength of alloy KhN60MVTYu is due to elastic distortion of the matrix resulting from the difference in the lattice constants of the γ and γ′ phases. 2. Aging of alloy KhN67MVTYu at 800° for 5000 h leads to disruption of the coherent bond between the γ′ phase and the matrix. Deformation occurs mainly by bending of particles by dislocations by the Orowan mechanism and also by cutting by dislocation pile-ups or separate partial dislocations with formation of stacking faults. 3. In alloy KhN60MKVYu with a large volume percentage of γ′ particles the location of γ′ particles in the matrix along crystallographic direction 〈100〉 favors the mechanism of cutting of the particles by superdislocations and is responsible for the combination of high strength and ductility.