Stabilization of ultrafine-grained microstructure in high-purity copper by gas-filled pores produced by severe plastic deformation

During the last decade severe plastic deformation (SPD) has become a widely known method of materials processing used for fabrication of ultrafine-grained materials with attractive properties. Nowadays SPD processing is rapidly developing and is on the verge of a transition from lab-scale research to commercial production. This paper focuses on several new trends in the development of SPD techniques for effective grain refinement, including those for commercial alloys and presents new SPD processing routes to produce bulk nanocrystalline materials.

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Investigations on Microstructure Evolution and Deformation Behavior of Aged and Ultrafine Grained Al-Zn-Mg Alloy Subjected to Severe Plastic Deformation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.667-669.253 ◽

2010 ◽

Vol 667-669 ◽

pp. 253-258

Author(s):

Wei Ping Hu ◽

Si Yuan Zhang ◽

Xiao Yu He ◽

Zhen Yang Liu ◽

Rolf Berghammer ◽

...

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Plastic Deformation ◽

Grain Size ◽

Severe Plastic Deformation ◽

Microstructure Evolution ◽

Deformation Behavior ◽

Deformation Mechanisms ◽

Mg Alloy ◽

Ultrafine Grained

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.

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MULTI-SCALE FINITE ELEMENT SIMULATION OF SEVERE PLASTIC DEFORMATION

International Journal of Modern Physics B ◽

10.1142/s0217979209061366 ◽

2009 ◽

Vol 23 (06n07) ◽

pp. 1621-1626

Author(s):

HYOUNG SEOP KIM

Keyword(s):

Plastic Deformation ◽

Finite Element ◽

Severe Plastic Deformation ◽

Constitutive Model ◽

Dislocation Cell ◽

Ultrafine Grain ◽

Angular Pressing ◽

Element Simulation ◽

Ultrafine Grain Size ◽

Ultrafine Grained

The technique of severe plastic deformation (SPD) enables one to produce metals and alloys with an ultrafine grain size of about 100 nm and less. As the mechanical properties of such ultrafine grained materials are governed by the plastic deformation during the SPD process, the understanding of the stress and strain development in a workpiece is very important for optimizing the SPD process design and for microstructural control. The objectives of this work is to present a constitutive model based on the dislocation density and dislocation cell evolution for large plastic strains as applied to equal channel angular pressing (ECAP). This paper briefly introduces the constitutive model and presents the results obtained with this model for ECAP by the finite element method.

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