On the localization of shearing deformations in tungsten heavy alloys

Abstract

This paper presents the results of an investigation into the dynamic shearing deformations of a WNiFe heavy alloy containing 91% W and with the Ni and Fe in a 7:3 ratio. The technique used to develop the dynamic shearing deformations is the torsional Kolsky bar, which generates shear rates as high as 10 3 s −1 for times of several hundred μs. Adiabatic shear localization has been observed in the high-rate shearing tests; relatively narrow shear bands are formed, followed immediately by catastrophic fracture. The deformed microstructures are examined using scanning electron microscopy, optical microscopy, and quantitative image analysis of the micrographs. Examination of the deformed microstructures supplies new insight into the mechanisms through which large dynamic shearing deformations occur in this tungsten heavy alloy.