Dear Colleagues,

Functionally-Graded Materials (FGM) have long been present in the history of humankind, in the shape of utensils made from materials of organic origin and taking advantage of naturally-occurring structural heterogeneities. Nevertheless, their acknowledgement as a clearly-defined engineering concept is rather recent, dating to the last quarter of the 20^th century.

There is currently a large set of domains where FGM can be found. The more traditional are probably some structural applications, where compositional and microstructural gradients imparted to the piece are taken advantage of to reunite in the same package properties that would otherwise not be found in the same material, but without incurring in the brittleness penalty resulting from an abrupt interface: the elegant katana sword blades, together with the perhaps humbler iron rail, are prime examples in this domain. At the other extreme, one can consider the effort being undertaken to mimic the bone structure, characterized by a smooth transition between an exterior compact tissue and an interior highly porous cancellous bone, to develop bone replacement scaffolds better suited for colonization by bone cells and with a mechanical behavior more akin to the natural tissue.

Smart materials rely on their chemical composition and processing condition for their response to stimuli. For applications requiring a wider controllable range, a wider range of the relevant physical parameters may be required. In such a situation, the possible solution will be to use a functionally graded smart material.

Furthermore, the FGM concept easily fuses into other notions. Thus, examples abound, both in scientific literature and technological contexts, of functionally graded composites and functionally graded foams, both instances where micro- and macro- or mesoscale heterogeneities are combined.

Publications are expected to offer contributions in the field of FGM focused on the topics reflected by the accompanying list of keywords.

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• Functionally graded materials
• Heterogeneous Materials
• Modelling
• Processing technologies
• Materials by Design
• Smart Materials
• Applications
• Cultural Heritage Materials