Evaluation of interface microstructure and mechanical properties of the diffusion bonded joints of Ti-6A1-4V alloy to micro-duplex stainless steel

摘要

In the present investigation, Ti-6A1-4V and micro-duplex stainless steel was diffusion bonded in vacuum. The layer wise σ phase and λ + FeTi phase mixture were observed at the bond interface when bonded joints was processed at and above 850℃ for 90min and at 800 ℃ for 120min and longer bonding time. Effect of bonding temperature and time on the strength properties at room temperature were evaluated. The maximum tensile strength of ~510.1 MPa and shear strength of ~397.5 MPa along with 6.5% elongation were obtained for the diffusion couple processed at 850 ℃ for 90 min. Fracture surface observation in SEM using EDS demonstrates that, failure takes place through λ + FeTi phase when bonding was processed at 850 ℃ for 90 min and at 800 ℃ for 120 min, however, failure takes place through cr phase for the diffusion couples processed at and above 900 ℃ for 90 min and at 800 ℃ for 120 min and longer bonding time.