Facilitating strong interfacial bonding of immiscible Nb/Cu system using consumable Ti interlayer

A novel consumable Ti interlayer strategy was developed to facilitate strong interfacial bonding between Nb and immiscible Cu by diffusion bonding at 850 degrees C. Bonding mechanisms of forming Ti-Cu intermetallic compounds (IMCs) at initial stage and subsequently eradicating IMCs upon diffusion induced Ti dilution were elucidated. IMCs free Nb/Cu joint composed of a Nb-Cu interdiffusion layer slightly alloyed with Ti was obtained at bonding duration of 40 min. Excellent bonding strength comparable to Cu substrate properties was achieved in 40 min joint attributed to building of metallurgical bonding at the interface and absence of brittle phases.