Solid-state diffusion bonding of superalloys for aerospace applications

Abstract

With a view of furthering the application of diffusion bonding in aerospace applications, the influences of processing parameters on the joining of nickel-based superalloy, ferritic ODS (Oxide Dispersion Strengthened) alloy and PH (Precipitation Hardened) stainless steel have been carried out and joints of good quality have been produced. The effect of bonding temperature, time, pressure and PBHT (Post Bonding Heat Treatment) on the bonding of Inconel 718 to itself was assessed. A post bonding heat treatment (PBHT) is helpful and crucial to produce a sound joint. The influence of pressure was studied for the bonding of Inconel 718 to 17-4 PH stainless steel. FEM (Finite Element Method) was carried out to assess the residual thermal stress. For the bonding of ODS alloy - Incoloy MA 956, in addition to the influence of bonding pressure, temperature and time, the influence of surface roughness was examined.