Microstructure characterization of Inconel 706 alloy

摘要

Inconel 706 a wrought Ni-Fe base superalloy which is used for high temperature services. It is age-hardened by precipitation of coherent γ' and/or γ" in the austenitic matrix γ. However, the microstructure of Inconel 706 is strongly dependent to the age-hardening treatment. Direct aging produces only γ'-γ" co-precipitates, while stabilization heat treatment produces additionally to the γ'-γ" co-precipitates the η precipitates which mostly form at the grain boundary. Characterization of the composition of precipitates and matrix were carried out by three-dimensional atom probe tomography. The microstructure was investigated by high resolution transmission electron microscopy.