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Metallurgical Transactions A

, Volume 15, Issue 10, pp 1883–1892 | Cite as

Modeling of dynamic material behavior in hot deformation: Forging of Ti-6242

  • Y. V. R. K. Prasad
  • H. L. Gegel
  • S. M. Doraivelu
  • J. C. Malas
  • J. T. Morgan
  • K. A. Lark
  • D. R. Barker
Mechanical Behavior

Abstract

A new method of modeling material behavior which accounts for the dynamic metallurgical processes occurring during hot deformation is presented. The approach in this method is to consider the workpiece as a dissipator of power in the total processing system and to evaluate the dissipated power co-contentJ = ∫o σ ε ⋅dσ from the constitutive equation relating the strain rate (ε) to the flow stress (σ). The optimum processing conditions of temperature and strain rate are those corresponding to the maximum or peak inJ. It is shown thatJ is related to the strain-rate sensitivity (m) of the material and reaches a maximum value(J max) whenm = 1. The efficiency of the power dissipation(J/J max) through metallurgical processes is shown to be an index of the dynamic behavior of the material and is useful in obtaining a unique combination of temperature and strain rate for processing and also in delineating the regions of internal fracture. In this method of modeling, noa priori knowledge or evaluation of the atomistic mechanisms is required, and the method is effective even when more than one dissipation process occurs, which is particularly advantageous in the hot processing of commercial alloys having complex microstructures. This method has been applied to modeling of the behavior of Ti-6242 during hot forging. The behavior of α+ β andβ preform microstructures has been exam-ined, and the results show that the optimum condition for hot forging of these preforms is obtained at 927 °C (1200 K) and a strain rate of 1CT•3 s•1. Variations in the efficiency of dissipation with temperature and strain rate are correlated with the dynamic microstructural changes occurring in the material.

Keywords

Metallurgical Transaction Flow Stress High Strain Rate Power Dissipation Dynamic Recrystallization 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© The Metallurgical Society of American Institute of Mining 1984

Authors and Affiliations

  • Y. V. R. K. Prasad
    • 1
    • 2
  • H. L. Gegel
    • 3
  • S. M. Doraivelu
    • 4
  • J. C. Malas
    • 3
  • J. T. Morgan
    • 3
  • K. A. Lark
    • 3
  • D. R. Barker
    • 4
  1. 1.Department of MetallurgyIndian Institute of ScienceBangaloreIndia
  2. 2.Air Force Wright Aeronautical Laboratories (AFWAL/MLLM)Wright-Patterson Air Force Base
  3. 3.AFWAL/MLLMWright-Patterson Air Force Base
  4. 4.Universal Energy Systems, Inc.Dayton

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