Functionally graded materials (FGMs) are advanced materials designed to satisfy special requirements or functions in a gradual manner. In other words, FGMs are materials with functionally graded structures and compositions adjusted to tailor certain properties. These kinds of materials were originally proposed to overcome the common problems at the interface in the case of multi layered materials with widely different properties. FGMs were first introduced by Japanese researchers in 1984 to be developed for use as thermal barrier materials. Since then, several research works have emerged and different methods were proposed to widen the applications of FGMs. This is due to the unique characteristics of FGMs, including gradual changes in volume fraction of the constituents, hence continuous graded hardness, wear resistance, thermal conductivity, specific heat and mass density, and corrosion resistance. Nowadays, FGMs are applicable in various fields including automotive, aerospace, mining, energy, and medical fields.

FGMs can be fabricated by powder metallurgy, deposition methods, centrifugal casting, and additive manufacturing techniques. However, some of these methods are uneconomical when bulk type FGMs are required. Therefore, the challenge when trying to widen the industrial applications of FGMs is to produce components with gradually distributed properties in a simple and economical manner.

This special issue invites researchers to submit their original research articles on processing and characterization of FGMs prepared using the different fabrication methods. Also, newly proposed methods and preliminary experiments are highly encouraged. Researchers who are new to the topic can take this chance to read about FGMs and submit their review articles.

Potential topics include but are not limited to the following:

• Theoretical aspects and mechanisms involved in fabrication of FGMs
• Characterization of functionally graded materials fabricated under centrifugal force
• Functionally graded materials prepared via powder metallurgy route
• Manufacturing of functionally graded materials by weld-deposition methods
• Functionally graded materials prepared by gas-based methods
• Additive manufacturing of functionally graded materials
• Modeling and analysis of functionally graded materials
• Functionally graded materials for biomedical implants
• Polymers-based functionally graded materials
• Newly proposed methods for preparation of functionally graded structures