| The effects of microstructure and fracture behavior on penetration performance, together with the dynamic torsional behavior using torsional Kolsky bar, of tungsten heavy alloys were investigated in the present study. Dynamic torsional tests were conducted for five alloys, one of which was fabricated by the double-cycled sintering process, and then the test data were compared via microstructures, mechanical properties, adiabatic shear banding, and fracture mode. The dynamic torsional test results indicated that in the double-sintered tungsten alloy whose tungsten particles were very coarse and irregular-shaped, cleavage fracture occurred in the center of the gage section with little shear deformation, whereas shear deformation was concentrated into the center of the gage section in the other conventional alloys. The deformation and fracture behavior of the double-sintered alloy correlated well with the observation of the impacted penetrator specimens and the in situ fracture test results, i.e., microcrack initiation at coarse tungsten particles and cleavage crack propagation through tungsten particles. These findings suggested that the cleavage fracture mode would 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. |
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