Accession Number:

ADA371489

Title:

Micromechanical Modeling of Superplastic Materials

Descriptive Note:

Final rept. 15 Jul 96-14 Jul 99

Corporate Author:

FLORIDA AGRICULTURAL AND MECHANICAL UNIV TALLAHASSEE

Personal Author(s):

Report Date:

1999-09-21

Pagination or Media Count:

127.0

Abstract:

In this work, superplastic deformation were studied at atomistic, mesoscopic and macroscopic levels with a special focus on the former two. At the atomistic level, we studied the energy and structure of symmetric tilt boundaries and examined the energy barriers during grain boundary sliding of Aluminum bicrystal. We also studied the effect of temperature and impurity atoms on the structure, energy and deformation of grain boundary sliding. At the mesoscopic level, polycrystal based micromechanical model was developed and append to conventional single-phase, dual-phase and high strain rate superplastic materials. This model has successfully predicted the flow-stress vs. strain rate and strain-rate sensitivity of conventional single-phase 7475 aluminium alloy, 2090-OE16 Al-Li alloy, and Al-Zn-Mg-Cu alloy, dual-phase Ti-6Al-4V and Zn-22Al, and high strain-rate materials IN905XL, IN9021 and IN90211. At macroscopic level, the effect of the state of strain uniaxial or biaxial on the origin and evolution of cavities is Al based alloys were studied. This model was also integrated with finite element code. Most of the results are available at our web site httpamml.eng.fsu.edu. In addition, an integrated web based simulation of SP process modeling was developed and implemented.

Subject Categories:

  • Properties of Metals and Alloys
  • Plastics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE