Abstract
As-cast SRR99 specimens were shot-peened and then annealed at 1250 and 1300°C for different times to investigate the kinetics of recrys-tallization. It was found that the relationship between annealing time and volume fraction of recrystallized grains could be described by the Johnson-Mehl-Avrami equation. Based on the kinetics analysis of the recrystallization process, the apparent activation energy for recrystalli-zation was determined. In addition, the microstructural evolution during the recrystallization process at 1300°C was studied. Inwards, recrystallization first occurs in the dendritic core regions at the shot-peened surface. With the dissolution of coarse υ' particles in the interdendritic regions, the recrystallized grain boundaries move through the interdendritic regions. Finally, the fully developed grains nearly have a uniform depth. The recrystallization process at the shot-peened surface is similar to that of wrought materials, which includes nucleation of recrystal-lization, growth of recrystallized nuclei into the matrix, and growth of recrystallized grains by swallowing up each other.
Original language | English |
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Pages (from-to) | 312-316 |
Number of pages | 5 |
Journal | Rare Metals |
Volume | 29 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2010 Jun |
Externally published | Yes |
Keywords
- Activation energy
- Kinetics
- Recrystallization
- Shot peening
- Single crystal superalloy
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Metals and Alloys
- Materials Chemistry