In the past one and a half decades, neutron and synchrotron radiation techniques have come to the forefront as an excellent set of tools for the wider investigation of material structures and properties, becoming available to a large user community. This holds especially true for metals, which are a fascinating class of materials with both structural and functional applications. With respect to these application classes, metals are used to engineer bridges and automotive engines as well as to exploit magnetic and electric properties in computer storage, optics, and electronics. Both neutron sources and synchrotrons are large user facilities of quantum-beam installations  with the implementation of a common accelerator or nuclear reactor-based source, often serving over 50 beamlines simultaneously and even more end stations. Up to a few thousand experiments are undertaken yearly, utilizing specialized beam conditions, sample environments, and detection systems. Their variations range across spectroscopy, diffraction, small-angle scattering, and inelastic scattering for sample sizes ranging from nanometers to meters. Examples of such installations can be found in the Topical Collection Facilities of Metals’ sister journal Quantum Beam Science.
The scope of the present Special Issue in Metals comprises articles on research case studies on individually selected systems. Fields of interest range from engineering, through materials design, to fundamental materials science, including non-exclusively, strain scanning, texture analysis, phase transformation, precipitation, microstructure reconstruction, crystal defects, atomic structures (both crystalline and amorphous), order and disorder, kinetics, time-resolved microstructure evolution, local structure correlations, phonons, deformation and transformation mechanisms, response to extreme conditions, local and integrated studies, both within the bulk and at interfaces. Regarding the breadth of the discipline, this contribution is not exhaustive by far, but stimulates important and evolving studies throughout the metals community.