DIFFUSION BONDING OF 2 SUPERALLOYS - DIFF USION ASPECTS AND MICROSTRUCTURE OF THE JOINT

Diffusion bonding is the prefered technique to join modern nickel base d superalloys such as an aero-engine disk type material (processed by powder metallurgy to resist low cycle fatigue at moderate temperature) and a large grain cast or directionally solidified material resisting to creep. The microstructure in the vicinity of the joint is affected by diffusion, especially the gamma' phase. In turn mechanical propert ies are affected by the transitions from one structure to the other.