Influence of Bonding Temperature on Structure and Strength Properties of Titanium and Micro-duplex Stainless Steel Diffusion Bonded Joints

Abstract

In the present study, diffusion bonding of titanium and micro-duplex stainless steel was investigated in vacuum. Diffusion interfaces were characterized using light microscopy, scanning electron microscopy and X-ray diffraction technique. The inter-diffusion of the chemical species across the diffusion interfaces were evaluated by electron probe microanalysis (EPMA). The maximum tensile strength of ~97% and shear strength of ~80% of those of Ti along with 6.9% elongation were obtained for the diffusion couple processed at 900°C joining temperature. Fracture surface observation in SEM using EDS demonstrates that, failure takes place through β-Ti phase when bonding was processed up to 850°C, however, failure takes place through λ+FeTi+β-Ti for the diffusion couples processed at 900°C and above bonding temperature.