Advanced metal additive manufacturing for sustainable production: Role of multiscale and nano-engineered materials

Metal AM has become an enabling technology for smart and sustainable manufacturing because of its advantages, including high material utilisation, design freedom and waste reduction in the production of complex parts. This review critically analyses the interactions among processing parameters, feedstock properties, microstructural changes and the operating performance of metal AM systems. Special focus is given to the transition from traditional metallic materials to materials systems featuring multiple length scales and/or nanoscale features, such as nanoparticle-reinforced metals, metal matrix nanocomposites and advanced alloy designs. Feedstock engineering, defect formation and the impact of new solid-state AM technologies on component quality and reliability are discussed. Moreover, the review emphasises the contribution of nano-engineered materials to grain refinement, bonding at the interfaces, mechanical property enhancement and multifunctional performance. The integrated process–feedstock–microstructure–property approach is suggested to develop high-performance and defect-controlled AM components. Lastly, prospects in the fields of intelligent process control, sustainable feedstock design and next-generation smart manufacturing systems are presented. This review provides a comprehensive overview of the use of advanced materials to facilitate sustainable and high-value metal AM.