Paper Title:
Nano Grained Structure in KOBO Extruded Bulk Products
  Abstract

There are several known severe plastic deformation (SPD) methods, which allow receiving nano-grained structure of materials. One of the methods is called the KOBO method (the name is composed of the first two letters of the surnames of the inventors: KOrbel and BOchniak). The method was used for extrusion of copper alloys at room temperature to manufacture thin-wall tubes. During the KOBO extrusion, reversible cyclic torsion of the material results in multiple changing the deformation path. Hence, a heavy localized plastic flow leads to shear bands development that reduces the total strain hardening effect and results in effective structure refinement. In particular, thin-wall tubes produced from single-phase copper alloys, intensively cooled close to the die outlet, had homogeneous structure consisting of fine grains/subgrains of a few hundreds nanometers in size. The final structure of the material is practically independent on the initial structure of processed billets. If the accelerated cooling of extruded material was omitted, grain coarsening to the size of dozens of micrometers was observed. In multi-phase copper alloys, the grain refinement was limited to about 1 μm, both for intensively cooled and air-cooled products.

  Info
Periodical
Pages
11-17
DOI
10.4028/www.scientific.net/JNanoR.10.11
Citation
W. Bochniak, L. Błaż, A. Korbel, "Nano Grained Structure in KOBO Extruded Bulk Products", Journal of Nano Research, Vol. 10, pp. 11-17, 2010
Online since
April 2010
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Anna Kula, Ludwik Blaz, Makoto Sugamata
Abstract:Rapid solidification (RS) combined with following mechanical consolidation of RS powders is considered as a valuable commercial method for...
165
Authors: Li Jia Chen, Jia Li, Feng Li, Xin Wang
Abstract:Cyclic deformation for two magnesium alloys AZ91 and AM50 with different processing status has been performed under total strain amplitude...
90
Authors: Tomasz Tokarski
Abstract:The present paper reports an experimental investigation of rapid solidification (RS) influence on the structure and mechanical properties of...
120
Authors: De Jiang Li, Xiao Qin Zeng, Xin Su, Yan Cai Xie, Wen Jiang Ding
Chapter 11: Magnesium Alloys
Abstract:Pre-cold rolling with the reduction of 15% was employed on Mg-8Gd-3Y-0.5Zr (wt.%) (GW83K) alloy in different initial states:...
1297
Authors: You Liang He, Fei Gao, Bao Yun Song, Rong Fu, Gui Ming Wu, Jian Li, Lan Jiang
Chapter 16: Severe Plastic Deformation
Abstract:Effective grain refinement through equal channel angular pressing (ECAP) for magnesium (Mg) alloys has been demonstrated by many researchers....
1781