**1. Introduction and Scope**

The research field of severe plastic deformation (SPD) offers innovative potential for manufacturing bulk metallic materials as well as for modifying their surfaces. Significant grain refinement can be obtained using hot, warm, cold, and even cryogenic deformations by SPD and Thermo-Mechanical Processing (TMP), or a combination thereof. In addition to grain refinement in the respective phases of the metallic materials, microstructural design on different hierarchical levels and even alloy design by phase formations and transformations during processing is possible by SPD and TMP. Examples include mechanically driven phase transformations, the formation of metastable phases, grain boundary engineering, and the formation of desirable textures.

This Special Issue contains the selected papers presented at the 3rd Symposium, "Severe Plastic Deformation and Thermomechanical Processing: Nanostructuring and Properties", which was organised as a part of EUROMAT congress in Stockholm, Sweden, 1–5 September, 2019.

The published papers report the use and recent advancements of different established as well as novel SPD processes like high-pressure torsion (HPT), Equal-Channel Angular Pressing (ECAP), High-Pressure Torsion Extrusion (HPTE) and Surface Mechanical Attrition Treatment (SMAT). In the scope of these studies are microstructural evolution, phase formations and grain refinement in singleand multi-phase alloys, strategies to enhance the microstructural stability at elevated temperatures as well as during thermal cycling and the improvement of mechanical and physical properties by SPD processing. Additionally, the biomedical properties of SPD-processed materials are investigated.
