Abstract
The Ni-base alloy, Inconel 718 was observed with high-resolution electron microscopy using by a high-voltage electron microscope in order to analyze the morphology of the interface between Laves-phases and the austenite matrix phases. The Laves-phase had a plate shape and had a (004)Laves||{111}γ; [110]Laves||<110>γ relationship in the interface with the matrix (γ). The interface had the step-structure although the interface looked like a planar shape macroscopically. It was considered that the step-structures were introduced to relax the lattice strain between the Laves-phases and the matrix. The step-structures were observed at intervals of almost 11.4–40.4 nm and 2.3–9.6 nm in the samples aged at 1073 and 1123 K, respectively. It was considered that the decrease of the interval of step-structure was due to the increase of the lattice strain between the Laves-phases and the matrix with increasing the aging temperature from 1073 to 1123 K.
