Temporal evolution of a bimodal distribution of gamma' precipitates in Ni-Al-Mo alloys influenced by coherency strains
The influence of coherency strains produced by the lattice mismatch delta on the decomposition process of Ni-Al-Mo alloys with a bimodal size distribution of the precipitates is presented. The evolution of microstructure and the kinetics of coarsening were studied using transmission electron microscopy (TEM). The lattice mismatch of each class of precipitates was determined by convergent-beam electron diffraction (CBED) and in-situ X-ray diffraction (XRD). Strong variations of the lattice parameter were detected within the matrix, and some regions showed tetragonal and orthorhombic distortions. A reduction of the coarsening rate of the large precipitates and an acceleration of the kinetics of the small particles was observed. It is suggested that all these effects are closely connected to the different strain fields surrounding precipitates in the different size classes.
Bibliographic Reference: Paper presented: Materials Research Society Fall Meeting, Thermodynamics and Kinetics of Phase Transformations, Boston (US), November 27-December 1, 1995
Availability: Available from (1) as Paper EN 40306 ORA
Record Number: 199710263 / Last updated on: 1997-04-01
Original language: en
Available languages: en