On the isotropy of the dynamic mechanical and failure properties of swaged tungsten heavy alloys

The quasi-static and dynamic mechanical and failure properties of a swaged tungsten-base heavy alloy rod have been investigated, with emphasis on the orientation of the specimens in the rod. Three orientations were considered, 0, 45, and 90 deg, with respect to the longitudinal axis of the rod. Compression, tension, and dominant shear tests were carried out. With the exception of the 0 deg orientation, all the orientations displayed quite similar mechanical characteristics in tension and compression. Dynamic shear revealed a critical strain for adiabatic shear failure of epsilon(c) approximate to 0.13, independent of the orientation and quite inferior to the quasi-static ductility. The present study confirms previous results obtained for one (generally unspecified) orientation and extends them to three orientations. Failure mechanisms were thoroughly characterized and it appears that significant damage does not develop prior to final failure. It is concluded that, for practical purposes, the swaged heavy alloy considered here can be regarded as isotropic from a mechanical and failure point of view, in spite of its microstructural anisotropy resulting from the swaging process.