CAD-based reconstruction of 3D polycrystalline alloy microstructures from FIB generated serial sections

This paper develops a robust CAD-based methodology for simulating 3D microstructures of polycrystalline metals using crystallographic input data on sections created by a focused ion beam (FIB)–scanning electron microscopy (SEM) system. The method is able to construct consistent polycrystalline microstructures with control on the resolution necessary for meaningful computational analysis in microstructure-property estimation. The microstructure simulation methodology is based on a hierarchical geometrical representation using primitives used in CAD modeling. It involves steps of data cleanup, interface point identification, polynomial and NURBS function-based parametric surface segments construction, generalized cell decomposition, geometric defeaturing, and gap and overlap removal. The implementation of the entire procedure described above is performed with the aid of user-programming facilities of a commercial CAD package Unigraphics NX3. The microstructure simulation algorithm is validated using various error criteria and measures for an extracted microstructure of a nickel superalloy.