ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Equal channel angular pressing (ECAP) was conducted at roomtemperature to a high strain level of ~24 in high purity copper. Tensile testing,Transition Electron Microscopy (TEM) and Electron backscatter diffraction (EBSD)were used to characterize the microstructure and property evolution with the increaseof ECAP strain. It was found that tensile yield strength and the stored energyincreases upon ECAP processing until a peak reached at 8~12 passes of ECAP, andtheir saturation was observed at higher ECAP passes. Continuous recrystallizationphenomenon in microstructure was observed, where dislocation free crystallites withlarge misorientation to their surrounding matrix and smaller than the nuclei fordiscontinuous recrystallization were observed embodied in the matrix of deformedstructure with high dislocation density. A two-step process was observed for theformation of these small crystallites, first the condensing of dislocation tangles into anarrow boundary, mostly low angle boundary; And second local migration (insub-micrometer range) of short grain boundaries, in strong contrast to the dramaticmigration of long large angle grain boundaries during discontinuous recrystallizationto swallow the deformed matrix, was observed leading to vanish of small subgrains
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.584-586.929.pdf
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