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http://dx.doi.org/10.5228/KSPP.2002.11.6.538

Assessment of Hot Deformation and Grain Size Distribution in a Udimet 720Li Pancake  

염종택 (한국기계연구원 재료기술연구소 공정연구부)
나영상 (한국기계연구원 재료기술연구소 공정연구부)
박노광 (한국기계연구원 재료기술연구소 공정연구부)
Publication Information
Transactions of Materials Processing / v.11, no.6, 2002 , pp. 538-546 More about this Journal
Abstract
Hot deformation behavior of Udiment720Li was characterized by compression tests in the temperature range of 10$25^{\circ}C$ to 115$0^{\circ}C$ and the strain rate range of $0.0005 s^{-1};to;5 s^{-1}$. The combination of dynamic material model (DMM) and Ziegler's instability criterion was applied to predict an optimum condition and unstable regions for hot forming. A dynamic recrystallization model coupled with FEM results was used to interpret the evolution of microstructures. In order to verify the reliability of the present coupled model, isothermal forging was performed in the temperature range 1050~115$0^{\circ}C$ at strain rates of $0.05 s^{-1};and;0.005 s^{-1}$. The present model was successfully applied to the hot forming process of Udimet720Li.
Keywords
Udimet 720Li; Dynamic Material Model; Instability Criterion; Dynamic Recrystallization; Isothermal Forging; FEM Simulation;
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