Nowadays, steel-titanium coupling is considered in chemical, nuclear, and airspace. In this work, the effect of bonding time and temperature on bonding of AISI 304 to Ti-6Al-4V by transient liquid phase bonding was investigated. A thin (25 ?m) foil of pure Cu was applied as the interlayer. Prior to TLP bonding, the surfaces to be joined and Cu interlayers were prepared by grinding and polishing down to 1200 grit and then cleansed with acetone in an ultrasonic bath. Afterwards, the interlayer was placed between the parent metals. The microstructures were investigated by optical and scanning electron microscopes. Energy dispersive spectroscopy (EDS) was performed in order to ensure the compositional variation of the joints. Microhardness measurements were used across the joint region using a Vickers micro-hardness indenter with a load of 50 g. Shear tests of the bonded samples were carried out to evaluate the shear strength of the TLP joints. The results showed that the intermetallic and eutectic compounds were removed at bonding temperature of 960 °C due to change in chemical composition of elements at interface. With increasing the bonding temperature, the width of joint zone was decreased and complete isothermal solidification rate was increased. EDS analysis indicated that various intermetallic phases at bonding temperatures of 870,900 and 930°C were formed. The highest hardness was recorded at case of 870 °C for 60 min. the maximum shear strength (374MPa) at 960 °C bonded joint was obtained. The fracture analysis showed different fracture morphologies for different bonding temperatures. The results of time variation at constant temperature of 960 °C showed that with increasing bonding time from 15 to 45 min, the width of the joint zone was raised. In contrast, with elevating bonding temperature, the joint zone width was decreased, indicating complete isothermal solidification at interface.
