Bonds Strength of St37 to SKF-Cu by Using Diffusion Welding

Different methods are used to produce bronze bearings with steel backing and bronze coatings. Technically, success of each method is dependent on the bonds strength and economically, production method is important. Temperature and pressure are two important variables in producing such bearings with appropriate bonds strength. This paper aims at studying temperature and pressure effects on the bonds strength of structural steel (St37) to pure commercial copper (SKF Cu), which has been produced using diffusion welding method. So, 18 sample pairs were used in 9 groups, each group containing 2 sample pairs. Diffusion was done in this way: 3 groups without any pressure, 3 groups with 1 MPa pressure, and 3 groups with 2 MPa pressure and 2 sample pairs of each group were diffused at boiling points 700, 850 and 920 C, respectively. Results show that there were no bonds in non- pressure condition at any temperature and also at 700C on all pressures conditions, while average bonds strength for 850C and 920C conditions were 2.2 and 5.4 MPa, respectively. So, for bonds between general structural steel and pure commercial copper, pressure is required with temperatures above 850 C.

Bond’s length; Bearing; Pressure; Temperature