Interface bonding property and strengthening mechanisms of Ta1/2A12 layered composite prepared by hot rolling

Ta1/2A12 layered composite is a promising passive shielding material, which can protect these spacecrafts from the damage of space radiation. In current work, Ta1/2A12 layered composite with an intermediate layer of 1060Al is successfully fabricated by hot rolling with a single pass rolling reduction of 53 % and a rolling temperature of 500℃. Thickness distribution of different component layer and interface microstructure have been carefully investigated. In contrast with the Ta1 layer bearing the smallest rolling reduction of 49.4 %, the intermediate layer of 1060Al presents the biggest rolling reduction of 69 % during the rolling-bond process. The Ta1/2A12 layered composite attains a high interface bonding strength of 97.11 MPa evaluated by the tensile shear test, indicating that an excellent interface bonding quality has been achieved in the hot rolling process. Main interface strengthening mechanisms are composed of four aspects, including strengthening of interfacial element interdiffusion between element Al and Mg at the interface between 2A12Al and 1060Al layer, enhancing of the formation of nanoscale interface layer with a width of about 0.3μm at the interface between Ta1 and 1060Al layer, combined reinforcement effects of grain refinement with an average grain size of 3.4μm and deformation hardening with a content of low-angle boundaries of 31 vol% for the intermediate layer of 1060Al, and strengthening by the generation of wave-like or wiggly interface. Moreover, the deformation behavior of each component layer in the rolling-bond process is enunciated. The formation mechanisms of wiggly or wave-like interface are also firstly proposed. These findings can offer a few novel understandings on designing the interface structure and fabricating layered composites with an exceptional interface bonding performance.