Functionally Graded Materials beyond Conventional Design: Multiscale Modeling, Advanced Manufacturing, and Emerging Engineering Applications

Abstract

Functionally graded materials (FGMs) are a new generation of superior materials that default compositions, microstructure, and functions with smooth changes in volume within a material. The paper is a thorough review of the history of FGMs since the 1980s when it was first developed in Japan, until now where it has seen a wide variety of uses in aerospace, biomedical and energy industries. The theoretical considerations of the design of FEM are systematically discussed in the paper the composition variability, optimization of the gradient, and mechanical and thermal behavior analysis. A special emphasis is laid on the functional graded additive manufacturing (FGAM) technology, which focuses on the optimization of procedures of the techniques, i.e. selective laser melting, fused deposition modeling, and the new multi-material additive manufacturing technology. Significant applications to engineering examined by the review are lightweight aerospace components, which have better thermal management, orthopedic implants, which have better integration and reduced stress shielding, and energy systems, which include new thermal barrier coating. In spite of the significant advances, the extensive industrial implementation of FGMs are still burdened by the challenges such as the excessive costs of production, the technical restrictions connected with defect control and standardization of quality products, and the inexistence of the regulatory frameworks. The paper ends with the definition of the future research directions, which include the use of artificial intelligence and machine learning in predictive design, the introduction of nanocomposite-enhanced FGMs, and convergence with smart technologies to monitor and adapt to real-time. These developments make FGMs become a key facilitator of sustainable, high-performance engineering solutions to the next-generation applications.