The structural design and superplastic forming/diffusion bonding of Ti2AlNb based alloy for four-layer structure

摘要

The multilayer structure of Ti2AlNb based alloy was fabricated based on the superplastic forming/diffusion bonding (SPF/DB) in this paper. The properties of superplasticity and diffusion bonding of Ti-22Al-27Nb alloy were investigated. The uni-axial tensile experiment showed that the tensile elongation reached up to 236% at the temperature of 970 degrees C with the strain rate of 3 x 10(-4) s(-1). Based on the superplasticity, the finite element analysis of structural design was carried out and the results showed that the honeycomb structure was flexible. And the diffusion bonding experiment was carried out at the temperature of 950 degrees C and 970 degrees C. Combining the microstructure of bonding interface with shear strength of different joints, the diffusion bonding parameter for present alloy was: 970 degrees C/10 MPa/2 h. The thickness distribution of the final structure was uniform and consistent with that of the FEA result, and the mechanical properties after SPF/DB reduced and the compressive strength of this structure behavior was about 7.7 MPa. (C) 2016 Elsevier Ltd. All rights reserved.