Effect of bonding temperature on the microstructure and mechanical properties of Ti-6Al-4V to AISI 304 transient liquid phase bonded joint

Highlights: • Ti-6Al-4V was successfully joined to stainless steel 304 by transient liquid phase (TLP) bonding using a Cu interlayer. • Complete isothermal solidification of the joint was occurred at 960 °C. • The mean shear strength and the isothermal solidification rate increased with increasing the bonding temperature. • 4-The maximum shear strength of the joint reach about 374 MPa. Transient liquid phase (TLP) bonding process was performed to join Ti–6Al–4V and AISI 304 austenitic stainless steel using a copper interlayer. The effect of the bonding temperature on the microstructure and mechanical properties was studied in the range of 870–960 °C. Microstructural characterization was carried out through optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results showed that the rate of isothermal solidification was increased by increasing the bonding temperature. In addition, when the bonding temperature was increased to 960 °C, the width of the eutectic and intermetallic zones was completely removed, leading to complete isothermal solidification. According to the results, a minimum hardness value of 216 VHN was measured in the joint zones and the highest shear strength was 374 MPa, as obtained for the sample joined at 960 °C. The fracture analysis showed different fracture morphologies for different bonding temperatures.