A shape interpolation procedure: Application to creating explicit grain structure models based on partial data sets

This paper reports a robust shape interpolation procedure for constructing a voxel-based model from a set of parallel 2D sections. The procedure is based on a morphing technique and is applicable to compact shapes of grains that appear in at least two consecutive sections. It relies on a set of images of the same resolution and containing the same sets of colors that correspond to different phases of the given volume. In addition to a simple demo example, we successfully apply the procedure to reconstruct the volumetric grain structure morphology of a thin Al-Mg oligocrystal specimen from two electron-back-scatter-diffraction scans of two parallel faces. For verification purposes the same physical specimen was machined down and two interior sections, parallel to the faces, were scanned. A good matching between reconstructed and actual grain structures at these two sections is observed. As a further illustration, the 3D shapes of several grains are extracted and shown. A demonstration of reconstruction from multiple sections using a dual-phase, martensite-ferrite representative volume element is also given. Finally, a quantitative analysis of false-positive results, as well as a way to decide the applicability of this method for grain reconstruction for a given material are described.