Cross slip and dislocation climb in Ni-base alloys

A PICASSO; A MARZOCCA; I ALVAREZ

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

Elsevier

Año: 1997 vol. 234- p. 1099 - 1102

0921-5093

An investigation of the minimum creep rate of two nickel-base superalloys, with low volume fraction of precipitates y? has shown that two mechanisms were operative at the temperatures 923 and 973 K and an extensive range of applied stresses. The experimental data were interpreted in terms of a new constitutive equation based on a creep model involving dislocations cross-slip in the matrix and dislocation climb at high stresses over the strengthening phase. This analysis has been used to obtain microstructural parameters involved in the model such as activation area and stacking fault energy. The apparent activation energy, ÄH measured by abrupt and small changes in  temperature were analyzed