Fracture Toughness and Fatigue Properties of Titanium Laminate Composites Produced by Controlled Diffusion Bonding.

摘要

An investigation of the use of laminate composites containing a weak interface to increase the fracture toughness of high strength titanium alloy has been conducted. Two billets were fabricated from 0.010inch Ti-6Al-4V material using a diffusion bonding process. Thin metal foils were used as interleaf materials. Results indicate that the use of a 0.0015inch Al foil as an interleaf leads to delamination ahead of the crack tip in the arrester orientation,and effectively blunts the crack. It was found that a 0.001inch commercially pure titanium foil used as an interleaf will not lead to delamination and splitting. Diffusion during the bonding process causes formation of a uniform material with no weak interface. Therefore,no delamination or splitting could occur in the composite material. It was also found that a propagating fatigue crack can be arrested at the interface in the arrester orientation. It was also determined that the crack growth rates of material which splits in the divider orientation are similar to rates obtained from full strength material. (Modified author abstract)