TLP bonding of Ti-6Al-4V to Al 2024 using thermal spray Babbitt alloy interlayer
(Department of Petroleum, Mining and Material Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran;)
Abstract: Thermal spray assisted transient liquid phase (TLP) bonding of Ti-6Al-4V to Al2024 alloys was investigated, where the interlayer was 80 μm Babbitt thermal spray coat on Al substrate. Thermal spray creates a rough and clean surface which leads to establishing a joint with higher strength. The optimized parameters were bonding temperature of 580 °C and bonding time of 30 and 60 min. Microstructural observation together with XRD patterns confirmed the existence of Al2Cu, Al2CuMg, Cu3Ti, TiAl3, TiAl and Mg2Sn intermetallic compounds formed in Al weld side. On the other hand, Ti3Al, Sn3Ti5 and Ti3Sn intermetallic compounds formed in Ti side. With increasing bonding time from 30 to 60 min, although the interlayer was not completely consumed, the thickness of remained Babbitt interlayer decreased to approximately 15 μm. The study showed that shear strength of the joint reaches the high value of 57 MPa obtained at larger bonding time of 60 min.
Key words: transient liquid phase; Al 2024 alloy; Ti-6Al-4V alloy; thermal spray; shear strength