Materials (Aug 2022)

Strain-Rate Dependence of Tensile Behavior in Commercial-Grade Tungsten—Effect of Recrystallization Condition

  • Byeong Seo Kong,
  • Ji Ho Shin,
  • Taejeong An,
  • Changheui Jang,
  • Hyoung Chan Kim

DOI
https://doi.org/10.3390/ma15175836
Journal volume & issue
Vol. 15, no. 17
p. 5836

Abstract

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The tensile deformation behavior of double-forged (DF-W) and recrystallized (RX-W) commercial-grade tungsten was investigated at 700 °C. With increasing strain rate, the dominant dynamic recrystallization (DRX) mechanism changes from continuous dynamic recrystallization (CDRX) to discontinuous dynamic recrystallization (DDRX). For DF-W, pre-existing sub-grains promote CDRX and associated a high-DRX fraction, resulting in reduced post-necking strain under a static condition. With increasing strain rate, a shift in the restoration mechanism from CDRX to DDRX contributes to the enhanced ductility in DF-W, while RX-W shows enhanced flow hardening without a loss of ductility. These results suggest that the strain-rate dependence of mechanical behavior depends on the initial microstructure.

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