ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
The Cyclic Extrusion Compression (CEC) is one of the methods of severe plasticdeformation (SPD), used for producing nanomaterials. The CEC method allows materials to bedeformed to arbitrarily large strains without changing the initial shape of sample. Large hydrostaticcompressive stresses are exerted during deformation avoiding sample cracking. Using the CECmethod Cu and aluminum alloys nanomaterials were produced. It has been found that, afterexerting true strain of about ϕ = 14, only some part of the sample changes into a nanomaterial,while the remainder volume still shows the ultrafine microstructure. The nanometric microstructureis created generally inside the areas of intersecting microbands. Large misorientation has beenfound between the microbands and the surrounding material, facilitating the formation of nanograinboundaries. The hardness of samples increases with the increase of deformation, however only to aboundary level of about 100 MPa. The stabilization of hardening, above a deformation of aboutϕ = 4, suggests the activation of softening processes. Independently to the stabilization ofproperties, the refinement of nanograins is continued, indicating the development of anomalies inthe hardening – grain size relationship
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/22/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.114.19.pdf
