Mapping dislocation densities resulting from severe plastic deformation using large strain machining

2018 ◽  
Vol 33 (22) ◽  
pp. 3762-3773
Author(s):  
Sepideh Abolghasem ◽  
Saurabh Basu ◽  
Shashank Shekhar ◽  
M. Ravi Shankar
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Large Strain ◽  
Dislocation Densities ◽  
Image Position

Abstract

Microstructural Design of an AlMgSi Alloy via ECAP Processing: An Advanced SPD Manufacturing Technique for NC/UFG Materials

2015 ◽  
Vol 1114 ◽  
pp. 143-148
Author(s):  
Nicolae Serban ◽  
Doina Răducanu ◽  
Vasile Danut Cojocaru ◽  
Nicolae Ghiban
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Shape Change ◽  
Large Strain ◽  
Metallographic Analysis ◽  
Cross Sectional ◽  
Ecap Processing ◽  
Microstructural Design ◽  
Almgsi Alloy

Severe plastic deformation (SPD) has received enormous interest over the last two decades as a method capable of producing fully dense and bulk ultra-fine grained (UFG) and nanocrystalline (NC) materials. Significant grain refinement obtained by SPD leads to improvement of mechanical, microstructural and physical properties. Compared to classical deformation processes, the big advantage of SPD manufacturing techniques, represented in particular by equal channel angular pressing (ECAP) is the lack of shape-change deformation and the consequent possibility to impart extremely large strain. In ECAP processing, the workpiece is pressed through a die in which two channels of equal cross-section intersect at an angle of ϕ and an additional angle of ψ define the arc of curvature at the outer point of intersection of the two channels. As a result of pressing, the sample theoretically deforms by simple shear and retains the same cross-sectional area to allow repeated pressings for several cycles. A commercial AlMgSi alloy was investigated in our study. The specimens were processed at room temperature for multiple passes, using three different ECAP dies. All samples (ECAP processed and as-received) were subjected to metallographic analysis and mechanical testing. Several correlations between the main processing parameters and the resulting microstructural aspect and mechanical features for the processed material were established. It was shown that severe plastic deformation by means of ECAP processing can be used in aluminum alloys microstructural design as an advanced tool for grain refinement in order to attain the desired microstructure and mechanical properties.

Role of Strain Gradient and Dynamic Transformation on the Formation of Nanocrystalline Structure Produced by Severe Plastic Deformation

2007 ◽  
Vol 539-543 ◽  
pp. 2787-2792 ◽  
Author(s):  
Minoru Umemoto ◽  
Yoshikazu Todaka ◽  
Jin Guo Li ◽  
Koichi Tsuchiya
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Strain Gradient ◽  
High Pressure Torsion ◽  
Large Strain ◽  
Nanocrystalline Structure ◽  
Angular Pressing ◽  
Dynamic Transformation ◽  
Fine Grained Structure

Formation of nanocrystalline structure by severe plastic deformation has studied extensively. Although ultra fine grained structure (grain size larger than 100 nm) had been obtained in many processes such as heavy cold rolling, equal channel angular pressing (ECAP) or accumulative roll bonding (ARB), the formation of nano grained structure (< 100 nm) is limited to processes such as ball milling, shot peening or drilling. In the present study, high pressure torsion (HPT) deformation and drilling were carried out to understand the conditions necessary to obtain nano grained structure in steels. The results of HPT experiments in pure Fe showed that HPT has superior ability of strengthening and grain refinement probably due to a strain gradient but the saturation of grain refinement occurs before reaching nano grained structure. Drilling experiments in high carbon martensitic steel revelaed that nano grained ferrite forms at the drilled hole surface only when the transformation from ferrite to austenite takes place during drilling. Considering various other processes by which nano grained ferrite was produced, it is proposed that heavy strains with large strain gradients together with dynamic transformation are necessary to reach nano grained ferrite structure.

Elaboration by Severe Plastic Deformation, Microstructural and Mechanical Study of Cu/X (X =Ta or Nb) Nanofilamentary Wires for Use in High Field Magnet

2006 ◽  
Vol 503-504 ◽  
pp. 639-644 ◽  
Author(s):  
Vanessa Vidal ◽  
Ludovic Thilly ◽  
Florence Lecouturier
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Field ◽  
Large Strain ◽  
Hot Extrusion ◽  
Cylindrical Structure ◽  
Mechanical Study ◽  
High Field Magnet ◽  
Two Systems

Nanofilamentary wires consisting of a Cu matrix reinforced by body centred cubic (bcc) nanofilaments were produced by successive hot extrusion and large strain drawing. Effects of this severe plastic deformation on the microstructure and the mechanical properties of two systems, Cu/Ta and Cu/Nb/Cu “co-cylindrical” structure, are presented and compared with the nanofilamentary Cu/Nb wires.

Interface-driven microstructure development and ultra high strength of bulk nanostructured Cu-Nb multilayers fabricated by severe plastic deformation

2013 ◽  
Vol 28 (13) ◽  
pp. 1799-1812 ◽  
Author(s):  
Irene J. Beyerlein ◽  
Nathan A. Mara ◽  
John S. Carpenter ◽  
Thomas Nizolek ◽  
William M. Mook ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Strength ◽  
Microstructure Development ◽  
Image Position

Abstract

Forced chemical mixing at Cu-Nb interfaces under severe plastic deformation

2012 ◽  
Vol 27 (12) ◽  
pp. 1621-1630 ◽  
Author(s):  
Nhon Q. Vo ◽  
Robert S. Averback ◽  
Yinon Ashkenazy ◽  
Pascal Bellon ◽  
Jian. Wang
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Image Position ◽  
Chemical Mixing

Abstract

scholarly journals Effect of strain rate in severe plastic deformation on microstructure refinement and stored energies

2011 ◽  
Vol 26 (3) ◽  
pp. 395-406 ◽  
Author(s):  
Shashank Shekhar ◽  
Jiazhao Cai ◽  
Saurabh Basu ◽  
Sepideh Abolghasem ◽  
M. Ravi Shankar
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Strain Rate ◽  
Microstructure Refinement ◽  
Image Position

Abstract

Incipient straining in severe plastic deformation methods

2014 ◽  
Vol 29 (5) ◽  
pp. 718-728 ◽  
Author(s):  
Fei Du ◽  
Shwetabh Yadav ◽  
Cesar Moreno ◽  
Tejas Gorur Murthy ◽  
Christopher Saldana
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Image Position

Abstract

Analysis of Severe Plastic Deformation by Large Strain Extrusion Machining

2008 ◽  
Vol 39 (11) ◽  
pp. 2645-2655 ◽  
Author(s):  
M. Sevier ◽  
H.T.Y. Yang ◽  
W. Moscoso ◽  
S. Chandrasekar
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Large Strain
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