Evaluation of the Applicability of Computer-Aided Porosity Testing Methods for Different Pore Structures

Abstract

AbstractPorosity plays an important role in the properties of powder metallurgy products and castings. Nowadays, there are several methods for determining porosity: optical microscopy, computed tomography, and density measurement according to Archimedes’ principle. The aim of this study is to present the advantages and disadvantages of different porosity testing methods and the relationships between the results. With conventional metallographic methods, only two-dimensional information about pores is obtained. The accuracy of a three-dimensional CT examination is significantly affected by the resolution, the quality of the image, and the evaluation process. The porosities of aluminum (AlSi7MgCu0.5) reduced pressure test samples with different densities were determined on 3D x-ray images with the evaluation software VGStudio MAX 3.3 and on 2D section x-ray images and the optical microscope images with the image analysis software ImageJ. The effect of morphological transformation of 3D images and the role of the region of interest volume and area under examination are also discussed.