Novel Tungsten-Based Composites: Designer Materials for Ultra-High-Rate Deformation and Failure
Final rept. 15 Sep 1995-14 Sep 1999
JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF MATERIALS SCIENCE AND ENGINEERING
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Broadly, the results under this grant are The thermoviscoplastic behavior of pure polycrystalline tungsten at high rates of deformation was measured. This is the basis for some models of tungsten-based composites. The mechanical behaviors of two modified tungsten phases made at Penn State and ARDEC were measured at high rates and high temperatures. A model was developed for this behavior. The mechanical behavior of an alternate matrix material hafnium was measured over a wide range of strain rates. The mechanical behavior of a tungsten-hafnium composite was measured using a wide range of strain rates and deformation modes. A model was developed to describe the observed constitutive response, based on the behaviors of the individual phases. A technique was developed for the recovery of samples in high-strain-rate pressure-shear experiments of a material to adiabatic shear localization under superimposed hydrostatic pressure.
- Laminates and Composite Materials