Study on Liquid Phase Diffusion Welding of Copper to Austenitic Stainless Steel using Cu-Ti Thin Alloyed Layer Deposited by Sputtering

Liquid phase diffusion welding of copper to austenitic stainless steel (SUS304) was studied. The surface of copper and SUS304 was cleaned by Ar ion beam bombardment and thin alloyed layer (Cu-30 wt.%Ti) was deposited on the bonding surface by sputtering. In this report, the effect of alloyed layer thickness on mechanical properties of liquid phase diffusion welded joints was investigated. The result indicated that: Mechanical properties of welded joints depended on alloyed layer thickness. Mechanical properties of welded joints equal to those of copper were obtained by the following condition: Alloyed layer thickness of 0.7μm, surface roughness of 0.7μm under, welding temperature 1213 K, pressure of 2.5 MPa and welding time of 3.6 ks.