Dynamic shear deformation and failure behaviour of pure polycrystalline tungsten

Woei Shyan Lee, Chi Feng Lin, Guo Liang Xiea

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)

Abstract

This study investigates the dynamic shear deformation and fracture behaviour of pure polycrystalline tungsten. Both wrought and recrystallized specimens are subjected to simple shear at room temperature and at strain rates ranging from 2×10-3 to 4×103 s-1 by means of a torsional split Hopkinson bar. The effects of strain rate on flow response, strain rate sensitivities, thermal activation volume and deformation mechanisms are investigated. Fracture phenomena are analyzed by scanning electron microscopy to evaluate damage initiation and propagation. Compared with quasi-static rate tests performed at 2×10-3 and 3×10-3 s-1, we find that strain rate obviously influences shear strength and ductility. Recrystallized tungsten exhibits better ductility and lower shear strength. Fracture feature observations show that, at low strain rate, recrystallized tungsten's equiaxial grain structure fractures by simple intergranular cleavage from grain boundary sources, whereas at high strain rate there is a mixture of intergranular and transgranular cleavage. Wrought tungsten's elongated fibrous structure, at low strain rate, fractures by an alternating mixture of intergranular and transgranular cleavage, but at high strain rate fractures by transgranular cleavage propagating across the whole specimen. We briefly discuss possible dynamic fracture mechanisms.

Original languageEnglish
Pages (from-to)102-112
Number of pages11
JournalMaterials Science and Engineering A
Volume247
Issue number1-2
DOIs
Publication statusPublished - 1998 Jun

All Science Journal Classification (ASJC) codes

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

Fingerprint Dive into the research topics of 'Dynamic shear deformation and failure behaviour of pure polycrystalline tungsten'. Together they form a unique fingerprint.

Cite this