Recrystallization of SRR99 single-crystal superalloy: Kinetics and microstructural evolution
来源期刊:Rare Metals2010年第3期
论文作者:ZHANG Binga,LIU Changkuia,HE Yuhuaia,TAO Chunhua,and LU Xinb a Failure Analysis Center of AVIC,Beijing Institute of Aeronautical Materials,Beijing ,China b School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing ,China
文章页码:312 - 316
摘 要:As-cast SRR99 specimens were shot-peened and then annealed at 1250 and 1300°C for different times to investigate the kinetics of recrystallization.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 recrystallization 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 γ’ 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 recrystallization,growth of recrystallized nuclei into the matrix,and growth of recrystallized grains by swallowing up each other.
ZHANG Binga,LIU Changkuia,HE Yuhuaia,TAO Chunhua,and LU Xinb a Failure Analysis Center of AVIC,Beijing Institute of Aeronautical Materials,Beijing 100095,China b School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China
摘 要:As-cast SRR99 specimens were shot-peened and then annealed at 1250 and 1300°C for different times to investigate the kinetics of recrystallization.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 recrystallization 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 γ’ 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 recrystallization,growth of recrystallized nuclei into the matrix,and growth of recrystallized grains by swallowing up each other.
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