Nanoporous Ni-based superalloy membranes by selective phase dissolution

Abstract

This article describes a study in which self-organization of the γ′-phase in nickel-based superalloys was used to create a microstructure where the former precipitate and matrix phases form interconnected networks that interpentrate each other. The selective dissolution of one phase leads to rigid structures with gas-permeable porosity on the nanoscale. Two basic manufacturing routes are described. One uses single-crystalline superalloys, leading to superior properties but also high manufacturing costs. The other utilizes conventional sheet forming of polycrystalline ingots.