Microstructural modifications in an explosively welded Ti/Ti clad material: II. Deformation structures around bonding interface

The residual deformation structures around the bonding interface in an explosively welded Ti/Ti clad material have been studied by optical microscopy and transmission electron microscopy (TEM). The microstructures around the bonding interface in the clad material welded at flyer plate speed of 420 m/s were consistent with the deformation structures of pure titanium under conventional quasistatic deformation around ambient temperature, except for the development of c + a dislocations just near the bonding interface and the presence of {10-13} twinning. The latter has been newly observed in pure titanium. The deformation modes within 50 μm from the bonding interface in system IV were essentially the same as those in pure titanium under conventional quasistatic deformation at elevated temperatures. The {13-41} twinning has been newly confirmed experimentally and was defined as an active twinning mode under high strain rate and/or at elevated temperatures. The microstructural aspects of adiabatic shear band (ASB) were also described.