On the Direct Diffusion Bonding of Titanium Alloy to Stainless Steel

Abstract

In the present study, direct diffusion bonding of Ti-6Al-4 V to 304 L stainless steel has been carried out in vacuum in the temperature range of 850–950°C using 3 MPa uniaxial load for 30 to 90 min durations. Different reaction layers in the diffusion zone have been examined by optical microscopy, scanning electron microscopy (SEM) using the back scattered mode, X-ray diffraction (XRD), and tensile testing. Analysis of the results of XRD and energy dispersive X-ray microanalysis has indicated the presence of intermetallic phases like Fe₂Ti, FeTi, Fe₂Ti₄O, and σ formed at different locations in the reaction zone. Maximum bond strength of 295 MPa is obtained for the diffusion bonded joint processed at 850°C for 60 min duration due to favorable width of the reaction zone.

Keywords:

• Diffusion bonding
• Microstructure
• Stainless steel
• Tensile strength
• Titanium alloy

ACKNOWLEDGMENTS

The authors gratefully acknowledge the financial support of the Indian Space Research Organisation, Government of India, for the present research work.