Experimental Investigation of Flexural Behavior of Diffusion Bonded Two Different Titanium Alloys

Diffusion bonding and superplastic forming has been a well-established joining technique for Ti-6Al-4V sheet materials in Aerospace Industry. This paper investigated the diffusion bonded dissimilar titanium alloy joints at different temperatures under flexural loading. In particular diffusion bonding was studied with titanium alloys Ti-54M, and Ti-6242 sheet materials. Quality of the joints was evaluated in terms of metallography and sub-surface micro-hardness hardness measurements. Effects of bonding interface quality were evaluated by characterizing the failure behavior using three point bend tests. Experimental results were analyzed by examining the effect of temperature, grain size, and hardness on the interface microstructure of diffusion bonded alloys.  Fractography study of fracture surfaces demonstrated the clear ductile mode of fracture. The study revealed that the influence of temperature on the bond quality and flexural strength was found to be dominant for a given bonding conditions of pressure and time.