Plastic deformation of CVD textured tungsten; 2: Characterization

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Acta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-7151(94)90075-2· OSTI ID:143918

Subhash, G; Lee, Y J; Ravichandran, G ^[1]

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1. California Inst. of Tech., Pasadena, CA (United States), Div. of Engineering and Applied Science

Deformation and failure modes of CVD textured tungsten in <001>, <011> and random orientations subjected to various loading rates under uniaxial compression are characterized using optical and electron microscopy. It is found that <001> orientation undergoes large homogeneous deformation in the range of strain rates investigated (10{sup {minus}}3{minus}10{sup 4}/s). Evolution of dislocation substructure in <001> tungsten is characterized by TEM studies. Under quasi-static loading rates, elongated dislocation cell formation is observed. At high strain rates, the dislocation density initially increases with respect to strain and then saturates when the temperature rise due to adiabatic heating becomes significant. At true strains beyond 2 the dislocations form well defined cells, with the cell walls containing very high dislocation densities. The deformation in <011> orientation is relatively less homogeneous under quasi-static loading, but under high strain rate loading the deformation is characterized by slip lines, extensive twinning and grain boundary cracking Fine grain polycrystalline specimens fail in a typical brittle manner.

• OSTI ID: 143918
• Journal Information: Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 1 Vol. 42; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BRITTLENESS
CHEMICAL VAPOR DEPOSITION
DEFORMATION
GRAIN ORIENTATION
TUNGSTEN