PREDICTION OF MICROSTRUCTURE DURING HIGH TEMPERATURE FORMING OF Ti-6Al-4V ALLOY

  • Lee Y. H. (Dept. of Materials Science and Engineering, POSTECH) ;
  • Shin T. J. (Dept. of Mechanical Engineering, POSTECH) ;
  • Yeom J. T. (Metal Working and Plasticity Group, Dept. of Materials Processing, KIMM) ;
  • Park N. K. (Metal Working and Plasticity Group, Dept. of Materials Processing, KIMM) ;
  • Hong S. S. (Agency for Defense Development) ;
  • Shim I. O. (Agency for Defense Development) ;
  • Hwang S. M. (Dept. of Mechanical Engineering, POSTECH) ;
  • Lee C. S. (Dept. of Materials Science and Engineering, POSTECH)
  • Published : 2003.10.01

Abstract

Prediction of final microstructures after high temperature forming of Ti-6Al-4V alloy was attempted in this study. Using two typical microstructures, i.e., equiaxed and $Widmanst\ddot{a}tten$ microstructures, compression test was carried out up to the strain level of 0.6 at various temperatures $(700\~1100^{\circ}C)$ and strain rates $(10^{-4}\~10^2/s)$. From the flow stress-strain data, parameters such as strain rate sensitivity (m) and activation energy (Q) were calculated and used to establish constitutive equations for both microstructures. Then, finite element analysis was performed to predict the final microstructure of the deformed body, which was well accorded with the experimental results.

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