Processing effects on the high-strain-rate response of hot-explosively-consolidated W-Ti alloys

Full-density, two-phase W-Ti alloy billets have been fabricated by a hot-explosive-compaction (HEC) technique. As part of the characterization effort, the high-strain-rate compressive behavior of these alloys was investigated. Split Hopkinson pressure bar (SHPB) tests of cylindrical samples taken from four differently processed alloy billets demonstrated the propensity of this type of material to fail via shear localization at high strain rates. The effects of the W:Ti ratio, post-HEC annealing treatment, and altered W and Ti precursor morphology were compared to the shear behavior of the untreated alloy. The localization susceptibility was found to increase with increasing Ti content and alloy strength, but was unaffected by density variations or microstructural coarsening in the matrix. When the volume fraction of the matrix phase was significantly reduced, deformation was more stable, with shearing becoming less localized. The experiments and the structural characteristics of the resultant localized regions are discussed.