Strengthening mechanisms in Inconel 718 superalloy

The yielding behaviour of underaged Inconel alloy 718, which is precipitation hardened by coherent ordered bct γ″ and ordered fcc γ′ phases, has been studied. It was found that the yielding of the underaged specimens occurs by the shearing of the precipitate particles by the glide dislocations which move in pairs. During this stage the yield strength of material can be adequately accounted for mainly by the coherency hardening mechanism.