Misfit dislocations and anisotropic coarsening in superalloys
The high temperature coarsening of the hardening precipitates in single crystal nickel-base superalloys is analysed in the light of the interfacial dislocation networks which develop to relieve the lattice mismatch. A criterion based on the ratio of interfacial energies in the principal directions is applied to the prediction of anisotropy in the microstructural morphology under different stress and temperature conditions. The new criterion represents a clear improvement over previous approaches. The range of stress-temperature prediction diagrams constructed for a number of real alloys shows good agreement with experimental behaviour. The prediction diagrams are also used to illustrate how the ratio of elastic moduli and the intrinsic lattice mismatch are the two relevant parameters governing the evolution of the morphology.
Bibliographic Reference: Paper presented: 30th Polish Solid Mechanics Conference, Zakopane (PL), September 5-9, 1994
Availability: Available from (1) as Paper EN 38871 ORA
Record Number: 199510434 / Last updated on: 1995-04-11
Original language: en
Available languages: en