Growth mechanisms of eta phase in 718Plus alloy

Abstract

Growth mechanisms of eta phase in 718Plus alloy were investigated by high-resolution scanning transmission electron microscopy. The results demonstrated the nucleation and growth of the η platelets were arranged along the {111}γ habit planes. The fine lamellae γ phase, enveloped in the η platelets blocks, was determined. The possible occurrence of interfacial misfit dislocations could effectively release the mismatch strain, and enhance the ledges nucleation on the {0001}η plane. Analysis of the experimental observations, and possible mechanisms of growth were also addressed.