In situ TiB-network-reinforced Al2O3/Ti6Al4V joints

A three-dimensional network architecture of TiB whiskers were in situ synthesized in Al2O3/Ti6Al4V joints by using Ni-B coated Cu foam interlayer. Boron was extracted from Ni-B alloy at low braze temperature to form a thin flexible boride layer comprised by TiB and Ni3B nano-particles. Subsequently, a network structure of TiB whiskers was developed from the interlaced boride layers at high temperature. The underlying mechanisms were addressed based on microstructural evolution. The uncoordinated deformation of the network microstructure, stress adjustments and crack-deflection effects of TiB whiskers contributed to the high shear strength of joints.