Features of CEC: Method, Structure & Materials Properties
AGH University of Science and Technology (AGH), al. Mickiewicza 30, Kraków 30-059, Poland
The Cyclic Extrusion Compression (CEC) is one of the methods of severe plastic deformation (SPD), which are used for the nanomaterials production. The CEC method allows deforming materials to the arbitrarily large deformations without the change of the initial shape of sample. The large hydrostatic compressive stresses are exerted during the deformation, preserving the sample cracking. Using the CEC method the nanomaterials from Cu and aluminum alloys were produced. It was found that, after exerting of true deformation of about j=14, only some part of sample changed into the nanomaterial, while the remainder volume still showing the ultrafine microstructure. The nanometric microstructure creates generally inside the areas of intersecting microbands. Large misorientation was found between the microbands and the surrounding materials, which facilitated the formation of boundaries of nanograins. The hardness of samples increased with the increase of deformation, however only to the some level of about 100 MPa, which appeared as the some boundary hardening of metallic nanomaterials. The slow increase of hardening, above of about the true deformation j=4, suggested the activation of the softening processes. Probably due these processes the arbitrarily increase of hardening is impossible. During the range of small hardening changes still the refinement of nanograins was observed, indicating that grain refinement exactly not fit with the changes of properties.
Presentation: invited oral at E-MRS Fall Meeting 2005, Symposium I, by Maria Richert
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-04-26 17:25 Revised: 2009-06-07 00:44