Superplastic behavior of a powder metallurgy superalloy during isothermal compression
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第11期
论文作者：Liming Tan Yunping Li Feng Liu Liang Jiang
文章页码：2591 - 2599
摘 要：In this work,the flow behaviors and microstructure evolution of a powder metallurgy nickel-based superalloy during superplastic compression is investigated.Based on the strain rate sensitivity m determined by flow data,superplastic region is estimated at relatively low temperature and strain rate domains,specifically around 1000 ℃/10-3s-1.Thereafter,the cylinder specimens are isothermally compressed at 1000 ℃/10-3s-1 and 1025 ℃/10-3s-1 with different strains,to exam the superplasticity and related mechanisms.The experimental results indicate that the accumulated dislocations are mainly annihilated by dynamic recovery and dynamic recrystallization（DRX）,and the grain boundary sliding（GBS）contributes to the total strain during superplastic compression as well.In addition,the cavities and cracks at triple junctions or interfaces between matrix and second phase particle have not been detected,which is different from superplastic tensile deformation.
Liming Tan1,2,3，Yunping Li1,2,3，Feng Liu1,2,3，Liang Jiang1,2,3
1. State Key Laboratory of Powder Metallurgy,Central South University2. Powder Metallurgy Research Institute,Central South University3. High Temperature Materials Research Institute,Central South University
摘 要：In this work,the flow behaviors and microstructure evolution of a powder metallurgy nickel-based superalloy during superplastic compression is investigated.Based on the strain rate sensitivity m determined by flow data,superplastic region is estimated at relatively low temperature and strain rate domains,specifically around 1000 ℃/10-3s-1.Thereafter,the cylinder specimens are isothermally compressed at 1000 ℃/10-3s-1 and 1025 ℃/10-3s-1 with different strains,to exam the superplasticity and related mechanisms.The experimental results indicate that the accumulated dislocations are mainly annihilated by dynamic recovery and dynamic recrystallization（DRX）,and the grain boundary sliding（GBS）contributes to the total strain during superplastic compression as well.In addition,the cavities and cracks at triple junctions or interfaces between matrix and second phase particle have not been detected,which is different from superplastic tensile deformation.
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