Effects of tungsten particle shape and size on dynamic deformation and fracture behavior of tungsten heavy alloys

Abstract

Dynamic torsional tests were conducted using a torsional Kolsky bar for five alloys, one of which was fabricated by double-cycled sintering process, and then the test data were compared via microstructures, mechanical properties, adiabatic shear banding, and fracture mode. The double-sintered tungsten alloy specimen whose tungsten particles mere very coarse and irregularly shaped showed cleavage fracture in the central area of the gage section with little shear deformation, whereas shear deformation was concentrated in the central area of the gage section in the other alloys. The deformation and fracture behavior of the double-sintered alloy correlated well with the observation of the impacted penetrator specimen and the in situ fracture test results, ie., microcrack initiation at coarse tungsten pal-tides and cleavage crack propagation through tungsten particles. These findings suggested that the cleavage fracture mode mould be beneficial for the self-sharpening effect and, thus, the improvement of the penetration performance of the double-sintered tungsten heavy alloy would be expected.