Effect of pure Ti thickness on the tensile behavior of laminated Ti-TiBw/Ti composites

A range of laminated Ti-TiBw/Ti composites containing Ti layers with different thicknesses and TiB whisker reinforced Ti (TiBw/Ti) composite layers with a constant of 400 μm thickness were successfully designed and fabricated by diffusion welding. The delamination between the two layers can be prevented during tensile process due to reasonable interfacial bonding strength. The tensile behavior shows that the strength of the laminated composites is gradually increased, while the ductility is decreased with the decrease of pure Ti thickness, and the fracture elongation can be characterized by necking severity and the number of tunnel cracks. Moreover, the laminated Ti-TiBw/Ti composites with thick Ti layer reveal gradient fracture characteristics: quasi-cleavage fracture in the TiBw/Ti layer, lath-like fracture and shear fracture in the pure Ti layer, and the fracture characteristics of laminated composites reveal a ductile to brittle transition (DBT) behavior with the decrease of Ti layer thickness.