Researches of the last years have allowed to establish that the laws of deformation and fracture of bulk ultrafine-grained (UFG) and coarse-grained (CG) materials are various both in static and in dynamic loading conditions. The influence of average grain size on the yield stress, the tensile strength, and the compression strength was established for metal alloys with a face-centered cubic (FCC), a body-centered cubic (BCC), and a hexagonal close-packed (HCP) structures. The study of the microstructure of the alloys after severe plastic deformation (SPD) by the electron backscatter diffraction (EBSD) technique showed the presence of a bimodal grain size distribution in the UFG alloys. Metal alloys with a bimodal grain size distribution possess a negative strain rate sensitivity of the yield stress and higher ductility at quasi-static strain rates. In this chapter, we will discuss the regularities of deformation at high strain rates, damage, and fracture of ultrafine-grained alloys.

In recent years, nanotechnology is the basis for the development of modern production. This determined the urgency of the intensive development of the new direction of mechanics and nanomechanics, for the scientific description of nanotechnological processes and the solution of several topical nanotechnology problems. Topics included in the book cover a wide range of research in the field of nanomechanics: thermomass theory of nanosystems; deformation of nanomaterials; interface mechanics of assembly carbon nanotube; nanomechanics on surface; molecular interactions and transformations; nanomechanical sensors, nanobeams, and micromembranes; nanostructural organic and inorganic materials; green synthesis of metallic nanoparticles. The main goal of these works is the establishment of the nanosystem macroparameter dependence on its nanoparameters using nanomechanics. This book will be useful for engineers, technologists, and researchers interested in methods of nanomechanics and in advanced nanomaterials with complex behavior and their applications.

Tensile strength, fatigue strength and ductility are important properties of nanostructured metallic materials, which make them suitable for use in applications where strength or strength-to-weight ratios are important. Nanostructured metals and alloys reviews the latest technologies used for production of these materials, as well as recent advances in research into their structure and mechanical properties. One of the most important issues facing nanostructured metals and alloys is how to produce them. Part one describes the different methods used to process bulk nanostructured metals and alloys, including chapters on severe plastic deformation, mechanical alloying and electrodeposition among others. Part two concentrates on the microstructure and properties of nanostructured metals, with chapters studying deformation structures such as twins, microstructure of ferrous alloys by equal channel angular processing, and characteristic structures of nanostructured metals prepared by plastic deformation. In part three, the mechanical properties of nanostructured metals and alloys are discussed, with chapters on such topics as strengthening mechanisms, nanostructured metals based on molecular dynamics computer simulations, and surface deformation. Part four focuses on existing and developing applications of nanostructured metals and alloys, covering topics such as nanostructured steel for automotives, steel sheet and nanostructured coatings by spraying. With its distinguished editor and international team of contributors, Nanostructured metals and alloys is a standard reference for manufacturers of metal components, as well as those with an academic research interest in metals and materials with enhanced properties.

This open access book gathers authoritative contributions concerning multiscale problems in biomechanics, geomechanics, materials science and tribology. It is written in memory of Sergey Grigorievich Psakhie to feature various aspects of his multifaceted research interests, ranging from theoretical physics, computer modeling of materials and material characterization at the atomic scale, to applications in space industry, medicine and geotectonics, and including organizational, psychological and philosophical aspects of scientific research and teaching as well. This book covers new advances relating to orthopedic implants, concerning the physiological, tribological and materials aspects of their behavior; medical and geological applications of permeable fluid-saturated materials; earthquake dynamics together with aspects relating to their managed and gentle release; lubrication, wear and material transfer in natural and artificial joints; material research in manufacturing processes; hard-soft matter interaction, including adhesive and capillary effects; using nanostructures for influencing living cells and for cancer treatment; manufacturing of surfaces with desired properties; self-organization of hierarchical structures during plastic deformation and thermal treatment; mechanics of composites and coatings; and many more. Covering established knowledge as well as new models and methods, this book provides readers with a comprehensive overview of the field, yet also with extensive details on each single topic.

Nanocrystalline (NC) and Ultrafine-grained (UFG) metal films exhibit a wide range of enhanced mechanical properties compared to their coarse-grained counterparts. These properties, such as very high strength, primarily arise from the change in the underlying deformation mechanisms. Experimental and simulation studies have shown that because of the small grain size, conventional dislocation plasticity is curtailed in these materials and grain boundary mediated mechanisms become more important. Although the deformation behavior and the underlying mechanisms in these materials have been investigated in depth, relatively little attention has been focused on the inhomogeneous nature of their microstructure (particularly originating from the texture of the film) and its influence on their macroscopic response. Furthermore, the rate dependency of mechanical response in NC/UFG metal films with different textures has not been systematically investigated. The objectives of this dissertation are two-fold. The first objective is to carry out a systematic investigation of the mechanical behavior of NC/UFG thin films with different textures under different loading rates. This includes a novel approach to study the effect of texture-induced plastic anisotropy on mechanical behavior of the films. Efforts are made to correlate the behavior of UFG metal films and the underlying deformation mechanisms. The second objective is to understand the deformation mechanisms of UFG aluminum films using in-situ transmission electron microscopy (TEM) experiments with Automated Crystal Orientation Mapping. This technique enables us to investigate grain rotations in UFG Al films and to monitor the microstructural changes in these films during deformation, thereby revealing detailed information about the deformation mechanisms prevalent in UFG metal films.

The investigation of nanocrystalline materials has been an extremely active field during the past two decades as it promises to yield new and exciting properties, which will both test the scientific understanding of the behaviour of materials in general, and offer new scope for applications. While considerable progress has been made in basic understanding, the shift from fundamental science to technological application has been slow, especially with regard to exploitation of the mechanical behaviour of these materials.

Bulk nanostructured (NS) metals, with structural units falling in the nanometer range, have emerged as a new class of materials. However, fabrication of artifact-free bulk NS metals with relatively large sample size still poses a challenge, the mechanical behavior needs to be further improved to achieve better combination of strength and ductility, and the fundamental understanding requires to be enhanced of the relationship between processing, microstructure and mechanical behavior. This dissertation selected Cu and Cu alloys as model materials to study processing, microstructure, mechanical behavior and deformation mechanisms of bulk NS metals. Bulk NS Cu and Cu alloys were fabricated by equal channel angular pressing (ECAP), spark plasma sintering (SPS) of cryomilled powders, or by high-pressure torsion (HPT) of coarse-grained or cryomilled powders, in efforts to simultaneously achieve high strength and satisfactory ductility, and to deepen our fundamental understanding of the microstructure and deformation mechanisms that govern the mechanical behavior of bulk NS metals. The temperature at which ECAP is conducted was found to have significant effect on microstructure evolution and mechanical behavior of ultrafine-grained Cu processed by ECAP. A superior combination of strength and ductility was achieved when ECAP was performed at 523 K where discontinuous dynamic recrystallization induces a high fraction of equiaxed grains with a very low dislocation density. During SPS of cryomilled nanocrystalline (nc) Cu powders, the presence of very small amounts of O and N in the powders, which were introduced during cryomilling and handling, and the change of these impurities during SPS were demonstrated to significantly influence the densification response. A bulk NS Cu-Zn-Al alloy with ultrahigh strength was fabricated via SPS of cryomilled powders. The microstructure of the alloy was thoroughly characterized, and various strengthening contributions were quantified, including grain boundary, twin boundary, second-phase particle, dislocation and solid-solution strengthening, and the calculated overall strength achieved a reasonable agreement with the experimental strength. The twins in the cryomilled Cu-Zn-Al powders and sintered bulk samples were carefully investigated, in an effort to provide insight into the mechanisms governing the evolution of twins during SPS, including grain boundary migration, twin boundary migration, recrystallization and detwinning. HPT was applied to coarse-grained (CG) and nc Cu powders, with identical processing parameters. HPT of CG Cu powders resulted in exceptional grain refinement and increase in dislocation density, whereas significant grain growth, via grain rotation-induced grain coalescence, and decrease in dislocation density occurred during HPT of cryomilled nc Cu powders. Equilibrium structures were achieved under both conditions, with very similar stable grain sizes and dislocation densities, suggesting dynamic balances between deformation-induced grain refinement and grain growth, and between dislocation accumulation and dislocation annihilation.