Grain refinement improves the mechanical properties and formability of metals and alloys. So far, several different grain refinement methods have been proposed and studied. Severe plastic deformation is one of the most promising and efficient methods. Therefore, in the present study the possibility of imposing a two-step severe plastic deformation (Extrusion and Equal channel angular pressing) ...

Abstract. Extensive research on severe plastic deformation (SPD) of metallic materials has been performed so far in order to improve mechanical properties, both at low and high temperatures. As a result the extensive grain refinement obtained, increased superplastic behaviour attained higher strains rates lower temperatures than usual. This is due finer sizes average misorientations which enhan...

Equal channel angular rolling (ECAR) process is one of the severe plastic deformation (SPD) methods that have been used to make ultra-fine grain (UFG) materials with improving the mechanical properties of samples. After performing the process at several paths, a large strain is applied to the material that can cause decreasing the grain size and improving the mechanical and physical properties ...

Among the severe plastic deformation processing (SPD) of materials, high-pressure torsion (HPT) is known to induce considerable amounts strain and crucial grain refinement up nanometer scale. There have been several reviews on mechanical properties and/or microstructure correlations SPD-processed materials published during last two decades. By contrast, a review crystallographic texture evoluti...

Superplasticity denotes the ability of a limited number materials to achieve exceptionally high tensile elongations at least 400%. Experiments show that Al-Mg-Sc alloys provide excellent capabilities for achieving superplastic flow and also they can be formed easily in biaxial forming operations. It is important, therefore, examine mechanism when alloy prepared using different procedures. This ...

Abstract. Ultra-severe plastic deformation (ulta-SPD) is a terminology used for the introduction of extremely large shear strains (over 1000) to material so that thickness sheared phases geometrically reaches subnanometer level. Under such extreme shearing conditions, new nanostructured with unique properties are formed even from immiscible systems. Various metallic alloys and ceramics were dev...

Microstructural evolution of NiTi shape memory alloy (SMA) with a nominal composition of Ni50.9Ti49.1 (at %) is investigated on the basis of heat treatment and severe plastic deformation (SPD). As for as-rolled NiTi SMA samples subjected to aging, plenty of R phases appear in the austenite matrix. In terms of as-rolled NiTi SMA samples undergoing solution treatment and aging, Ni4Ti3 precipitate...

Equal channel angular pressing (ECAP) is one of the most prominent procedures for achieving ultra-fine grain (UFG) structures among the various severe plastic deformation (SPD) techniques. In this study, the effect of ultrasonic vibration on deformation behavior of commercial pure aluminum in the ECAP process is analyzed successfully using three dimensional (3D) by finite element methods (FEMs)...

expansion equal channel angular extrusion (exp-ecae) is a severe plastic deformation (spd) operation for processing bulk materials. in the current study, aa7075 al was spd-processed by expansion equal channel angular extrusion (ex-ecae) at various temperatures and ram velocities. then, using split hopkinson pressure bar (shpb), the severely deformed products were compressed at room temperature ...