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:
Copper sheet samples composed of nanometer scale lamellar twins was produced byelectrodeposition. The coherent lamellar twin boundaries were within 20˚ of being parallel to thesheet plane in more than 60% of the grains. The electrodeposited sample was cold rolled to 30 and85% reductions in thickness and the structural evolution during cold rolling was examined bytransmission electron microscopy (TEM) and high resolution TEM (HRTEM). Extensive activity ofpartial dislocations along twin boundaries and of perfect dislocations within twins (in particular incoarse twins 〉100nm) were identified. Moreover, it was found that shear banding occurred, whichlocally destroyed the lamellar twin structure. A dislocation structure developed within the shearbands, and such a structure evolved with strain and gradually replaced the lamellar twin structure.After 85% deformation, a large volume fraction of the lamellar twin structure was replaced by alamellar dislocation structure characteristic of high strain rolling where the lamellar dislocationboundaries are almost parallel to the rolling plane. It was also found that the structural scales arecoarser in the lamellar dislocation structure than in the initial lamellar twin structure
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.5013.pdf
