Real hydrostatic pressure in high-pressure torsion measured by bismuth phase transformations and FEM simulations

Kaveh Edalati, Dong Jun Lee, Takashi Nagaoka, Makoto Arita, Hyoung Seop Kim, Zenji Horita, Reinhard Pippan

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)

Abstract

Hydrostatic pressure is a significant parameter influencing the evolution of microstructure and phase transformations in the high-pressure torsion (HPT) process. Currently, there are significant arguments relating to the magnitude of the real hydrostatic pressure during the process. In this study, phase transformations in bismuth, copper and titanium combined with the finite element method (FEM) were employed to determine the real pressure in processing disc samples by HPT. Any break in the variation of steady-state hardness (monitored experimentally by in-situ torque and temperature rise measurements) versus pressure was considered as a phase transition. FEM simulations show that the hydrostatic pressure is reasonably isotropic but decreases with increasing distance from the disc center and remains unchanged across the disc thickness. Both experiments and simulations indicate that the mean hydrostatic pressure during HPT processing closely corresponds to the compressive load over the disc area plus the contact area between the anvils.

Original languageEnglish
Pages (from-to)533-538
Number of pages6
JournalMaterials Transactions
Volume57
Issue number4
DOIs
Publication statusPublished - 2016

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Real hydrostatic pressure in high-pressure torsion measured by bismuth phase transformations and FEM simulations'. Together they form a unique fingerprint.

Cite this