Solid state diffusion bonding of IncoHoy IVIA 956 to itself

摘要

Oxide dispersion strengthened (ODS) superalloys have superior mechanical and corrosion resistance at high temperatures compared to conventional superalloys. This readily explains the driving force for the replacement of wrought or cast nickel-based superalloys by ODS materials, for applications in environments where highly stressed components are exposed to high temperatures and aggressive gasses, such as burning chamber components, gas turbine blades, etc. 11J. Incoloy MA 956 is a kind of ferritic ODS superalloy. It has superior high temperature strength, second phase particle dispersion strengthening, and improved resistance to oxidation, carburization, and hot corrosion. As a result, the industrial application of this alloy is gradually increasing. Development of a suitable joining technology is essential for this alloy type because components with complicated cooling design cannot be made by other methods. However, a reliable joining technique for this kind of alloy is not currently available, and this limits or precludes its use in many industrial applications. Solid state diffusion bonding does not create a molten zone at the joint interface. Agglomeration or coarsening of oxide particles may thus be avoided, and joints having mechanical properties that match the base material could be obtained [2, 31. A very limited amount of research has been published on the solid state diffusion bonding of Incoloy MA 956 alloy, and results reported to-date are not very conclusive. In this paper some results on the solid state diffusion bonding of Incoloy MA 956 to itself are presented. Among the various possible process parameters, only the effect of the bonding pressure on the joint inicrostructure was investigated.