The Microstructure and Gamma Prime Distributions in Inertia Friction Welded Joint of P/M Superalloy FGH96
A gamma prime (γ′) precipitation (~35% in volume)-hardened powder metallurgy (P/M) superalloy FGH96 was welded using inertia friction welding (IFW). The microstructure and γ′ distributions in the joints in two conditions, hot isostatic pressed state and solution-treated and aged state, were characterized. The recrystallization of grains, the dissolution and re-precipitation of γ′ in the joints were discussed in terms of the temperature evolutions which were calculated by finite element model analysis. Regardless of the initial states, fully recrystallized fine grain structure formed at welded zone. Meanwhile, very fine γ′ precipitations were re-precipitated at the welded zone. These recrystallized grain structure and fine re-precipitated γ′ resulted in increasing hardness of IFW joint while making the hardness dependent on the microstructure and γ′ precipitation.
Keywordsgamma prime (γ′) hardness inertia friction welding microstructure powder metallurgy nickel-based superalloy
This work was supported by the Fundamental Research Funds for the Central Universities of China and the open fund of the Key Laboratory for Metallurgical Equipment and Control of Ministry of Education in WUHAN University of Science and Technology, China.
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