Mechanical Properties of UFG Metals

UFG metals and alloys attract the materials science community owing to their superior mechanical properties. This chapter considers achieving enhanced mechanical properties in the UFG materials processed by SPD techniques. Special emphasis is laid on the examples and origins of the phenomenon of superstrength as well as the description of the hardening mechanisms in the materials. The chapter views the manifestation of the SPD paradox caused by the formation of equiaxial UFG structure and control of grain boundary type and segregations. The SPD paradox is evident in the simultaneous growth of strength and ductility. Mechanisms for enhancing the ductility of UFG materials are considered. The chapter also focuses on the importance of grain refinement in increasing fatigue strength and endurance, creep resistance of materials, the manifestation of the superplasticity effect at lower temperatures, and higher strain rates and its use in superplastic forming of complex shape parts. Advanced mechanical properties of UFG materials provide excellent opportunities for manufacturing new promising products for practical applications.