The mechanical behavior of nanolaminates is dominated by interfaces that act as sources, barriers, and preferred sites for storage and dynamic recovery of glide dislocations. In this article, the deformation mechanisms of a variety of metal-based nanolaminates are reviewed with emphasis on unusual mechanical properties such as ultra-high flow strength without loss of plastic deformability. GRAPHICAL ABSTRACT IMPACT STATEMENT This paper reviews the current understanding of the mechanisms and mechanics of nanolaminated composites, and discusses the future direction in predicting the mechanical behavior of laminated composites.

Material performance in extreme radiation environments is central to the design of future nuclear reactors. Radiation induces significant damage in the form of dislocation loops and voids in irradiated materials, and continuous radiation often leads to void growth and subsequent void swelling in metals with low stacking fault energy. Here we show that by using in situ heavy ion irradiation in a transmission electron microscope, pre-introduced nanovoids in nanotwinned Cu efficiently absorb radiation-induced defects accompanied by gradual elimination of nanovoids, enhancing radiation tolerance of Cu. In situ studies and atomistic simulations reveal that such remarkable self-healing capability stems from high density of coherent and incoherent twin boundaries that rapidly capture and transport point defects and dislocation loops to nanovoids, which act as storage bins for interstitial loops. This study describes a counterintuitive yet significant concept: deliberate introduction of nanovoids in conjunction with nanotwins enables unprecedented damage tolerance in metallic materials.