ADIABATIC SHEAR FAILURE OF PRE-TORQUED TUNGSTEN HEAVY ALLOY UNDER COMBINED DYNAMIC COMPRESSION/SHEAR LOADING

摘要

A combined compression/shear testing method was used in order to investigate the propensity of pre-torqued tungsten heavy alloy containing 93% W and 7% Ni-Fe on the 7:3 ratio. The combined simultaneous loading is applied by a split Hopkinson pressure bar (SHPB), which generates strain rate as high as 10V. The cylindrical specimen has its axis inclined to the loading axis. Adiabatic shear localization has been observed in the high rate compression/shear tests; relatively narrow shear bands are formed, followed immediately by catastrophic fracture. The deformed microstructures are examined using electron microscopy and optical microscopy. Examination of the deformed microstructures supplies new insight into the failure mechanism of the pre-torqued tungsten heavy alloy.