Synthesis and mechanical property evaluation of Ti-TiAl metal-intermetallic microlaminate composite

A microlaminate consisting of Ti and α₂-Ti ₃Al+γ-TiAl has been synthesized using electron beam physical vapor deposition technique. The microstructure and various properties have been explored. It is demonstrated that the nano-hardness and elastic modulus of Ti layer and Ti-Al layer are of gradient distribution according to the distance to the interface layer which may be results from the pile-up effect and the stress concentration at interface. The presence of Ti layers will lead to the cracks stagger along the inter-laminar interface or the layer due to which micro laminate expresses a good characteristic of delayed fracture. The toughening mechanisms are that the crack deflection and micro-bridge connection caused by the toughening layers increases crack propagation resistance.