Effect of bonding time on the joint properties of transient liquid phase bonding between Ti-6Al-4V and AISI 304

Transient liquid phase (TLP) bonding was employed to join Ti-6Al-4V and AISI 304 through a copper interlayer. The effect of the bonding time on the interfacial and mechanical properties of the UP bonded was investigated at 960 degrees C. The morphology of the joints was evaluated by optical microscopy, scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The results showed that the width of the joint was increased and then decreased with enhancing the bonding time. The occurrence of different intermetallic compounds such as Ti2Cu, Ti2Cu3, TiCu2, TiCu4, TiCu and FeTi was predicted for different bonding times, except at 60 min. Prolonging the holding time from 15 to 60 min resulted in a joint solidified isothermally, producing the single phase solid solution beta-Ti at the interface. The results from mechanical testing also showed that the maximum shear strength of 374 MPa was obtained with the bonding time of 60 min, which was equal to 70% of the Ti-6Al-4V strength. Observation of fracture surfaces revealed two kinds of failure modes: brittle and mixed brittle-ductile. (C) 2017 Elsevier B.V. All rights reserved.