Bulk nanostructured materials from severe plastic deformation
RZ Valiev, RK Islamgaliev, IV Alexandrov - Progress in materials science, 2000 - Elsevier
RZ Valiev, RK Islamgaliev, IV Alexandrov
Progress in materials science, 2000•ElsevierIn recent years, bulk nanostructured materials (NSM) processed by methods of severe
plastic deformation (SPD) have attracted the growing interest of specialists in materials
science [1]. This interest is conditioned not only by unique physical and mechanical
properties inherent to various nanostructured materials, eg processed by gas condensation
[2, 3] or ball milling with subsequent consolidation [4, 5], but also by several advantages of
SPD materials as compared to other NSM. In particular, SPD methods resulted in …
plastic deformation (SPD) have attracted the growing interest of specialists in materials
science [1]. This interest is conditioned not only by unique physical and mechanical
properties inherent to various nanostructured materials, eg processed by gas condensation
[2, 3] or ball milling with subsequent consolidation [4, 5], but also by several advantages of
SPD materials as compared to other NSM. In particular, SPD methods resulted in …
In recent years, bulk nanostructured materials (NSM) processed by methods of severe plastic deformation (SPD) have attracted the growing interest of specialists in materials science [1]. This interest is conditioned not only by unique physical and mechanical properties inherent to various nanostructured materials, eg processed by gas condensation [2, 3] or ball milling with subsequent consolidation [4, 5], but also by several advantages of SPD materials as compared to other NSM. In particular, SPD methods resulted in overcoming of a number of difficulties connected with residual porosity in compacted samples, impurities from ball milling, processing of large scale billets and practical application of the given materials. The principle of processing of bulk nanostructured materials using SPD methods is an alternative to the existing methods of nanopowder compacting. It is well known that heavy deformations, for example, by cold rolling or drawing, can result in significant refinement of microstructure at low temperatures [6±9]. However, the structures formed are usually substructures of a cellular type having boundaries with low angle misorientations. At the same time, the nanostructures formed from SPD are ultra fine-grained structures of a granular type containing mainly high angle grain boundaries. 1 Formation of such nanostructures could be realized by SPD methods providing very large deformations at relatively low temperatures under the high pressures imposed [1, 10, 11]. Special methods of mechanical deformation were developed and used for realization of this principle. These methods are as follows: severe torsion straining under high pressure, equal channel angular pressing and others. It was shown that using SPD methods one can fabricate bulk nanostructured samples and billets out of different metals and alloys including a number of commercial alloys and intermetallics.
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