On the deformation and fracture of a bone-like structure titanium

A set of hierarchical and laminated titanium with optimized mechanical properties and crack tolerance was designed inspired by the substructure of bone. The bone-like Ti with varying load-bearing structures was produced by rolling, annealing, and electron beam local heat treatment. Fibrous-like ultrafine-grained structures are wrapped in the outmost layer as a load-bearing matrix. The internal layer is a laminated structure with periodic medium-sized grains, coarse grains, and fine needle-like grains (hierarchical distribution). Sharp and gradient interlayer interfaces were simultaneously developed. The bone-like structure Ti with higher strength of the outmost layer showed higher strain hardening, which came from the higher strain gradient near the soft layer. The existence of interfaces and soft layers is important for the effective improvement of strain hardening and crack resistance. Analysis of the crack path shows that the present hierarchical and laminated structure Ti showed excellent crack resistance by deflecting the crack propagation path. These observations provide insights into the architectural design and deformation studies of biocompatible materials.