Voxel-based design and characterization of functionally graded materials

Functionally graded materials (FGM) have numerous merits that are appealing to various industrial sectors. Great advancements have been made in FGM manufacturing technologies during the past few decades, especially in voxel-based 3D printing in recent years. Nevertheless, the development of FGM design and characterization methods is considerably lagging behind. The existing FGM design methods are mostly geometry based, and the characterization of FGM properties mainly relies on the conventional micromechanical models; both have fundamental limitations that severely hinder the wide application of FGMs in industries. In this study, two types of voxel-based approaches, i.e., micromechanics-based and statistics-based, are developed for FGM design and characterization. Four representative FGMs are designed and characterized using the proposed approaches. The study results show that FGM properties are dependent on the resolution of FGM image for both the approches, particularly if the phase materials have large contrast in their properties. For the micromechanics-based methods, FGM properties are also dependent on the micromechanics formula that is used in the determination of voxel effective properties. The study shows that the statistics-based approach is more reliable and more accurate. With the new voxel-based 3D printers generally available to the industry, the proposed voxel-based design and characterization approaches will have wide applications in various industrial sectors such as aerospace, energy, biomedical and electrical engineering.