Development of Nano-Structured Metals Processed by Severe Plastic Deformation

Abstract

Severe Plastic Deformation is the most promising technique which can produce Bulk Nano-Structured Materials (BNMs). Among various SPD techniques Accumulative Roll Bonding (ARB) and Equal Channel Angular Pressing (ECAP) have a broad significance due to its unusual mechanical performance. In this paper, the principle and merits of ARB and ECAP technique are pointed out, and also a model based on simulation is established for investigating SPD developments. Pure Copper after sixteen numbers of ARB cycles discloses greater strength by more rises in ductility as compared to that of coarse-grained metals. Similarly in pure Titanium after five numbers of ARB cycles incredibly substantial increase in strength together with an only small decrease of ductility has obtained. The result shows that it is achievable to get high strength, except only with significantly reduced ductility.Additionally, a simulated model, founded on lattice defect kinetics has established. This model holds true parameters like dislocation density, vacancy concentration, grains size, etc., found appropriate for the grain refinement throughout and after the SPD process of simulation. It presents quantitatively consistent outcome for the hardening performance and micro-structural development in pre and post SPD deformation. The new results of SPD-processed nano-structured materials are elucidated, particularly considering viable uses. The advantages of nano-structured metals and alloys mostly for aerospace engineering, automotive engineering, electronic industry and for biocompatible are pointed out such as improved hydrogen storage kinetics (Mg-alloys) for fuel cell technology, superior magnets, Ti, Mg-alloys for prostheses, implants, and stents, etc.