Solid state diffusion bonding of Inconel 718

Solid state diffusion bonding of Inconel 718 has been studied. Mechanical t ests and metallographic examinations were used to evaluate the joint qualit y. The effect of bonding time, temperature, and pressure on the joint integ rity was assessed. The results showed that partial recrystallisation occurs in joints bonded at temperatures lower than 970 degreesC In addition, larg e amounts of delta phase precipitates were also found and both the ductilit y and the tensile strength were poor. Nevertheless, the joint strength was comparable to that of the parent metal when bonding was carried out tit tem peratures greater than 970 degreesC When bonding was carried out at 1000 de greesC, a pressure of 32 MPa, and a bonding time of 30 min, the joint tensi le strength obtained was 874 Wa. There was no further improvement with incr easing bonding time beyond, 240 min.