Enhanced creep properties of copper and its alloys processed by ECAP

0435683 - ÚFM 2015 RIV GB eng C - Konferenční příspěvek (zahraniční konf.)
Dvořák, Jiří - Král, Petr - Svoboda, Milan - Kvapilová, Marie - Sklenička, Václav
Enhanced creep properties of copper and its alloys processed by ECAP.
NANOSPD 6. Bristol: IOP Publishing Ltd, 2014 - (Benoît, B.; Olivier, B.; Emmanuel, B.; Thierry, G.), Art. No. 012141. IOP Conference Series: Materials Science and Engineering, 63. ISSN 1757-8981.
[NanoSPD 2014 - International Conference on Nanomaterials by Severe Plastic Deformation /6/. Metz (FR), 30.06.2014-04.07.2014]
Grant CEP: GA ČR(CZ) GAP108/11/2260; GA MŠMT(CZ) ED1.1.00/02.0068
Institucionální podpora: RVO:68081723
Klíčová slova: Copper alloys * Creep * Microstructure * UFG materials
Kód oboru RIV: JJ - Ostatní materiály
http://iopscience.iop.org/1757-899X/63/1

This work describes the effect of ECAP technique on the microstructure and creep properties of pure Cu and its alloys with addition of Zr or Co. The ECAP pressing was performed at room temperature by route Bc up to 12 passes. Ultrafine-grained (UFG) microstructure has been studied by methods of TEM and SEM-EBSD. Tensile creep tests were conducted at temperature 673 K and at different applied stresses on ECAP material and, for comparison purposes, on unpressed coarse-grained (CG) states. It was found that both alloys processed by ECAP exhibited similar character of creep behaviour. Creep resistance was markedly improved after first two ECAP passes in comparison with its unpressed state. The minimum creep rate of ECAP material may be up to two orders of magnitude lower than that of CG material. However, subsequent ECAP passes lead to a decline of creep life and the difference in the minimum creep rate for the ECAP material and CG state consistently decreases with increasing number of ECAP passes. Further, ECAP process led to significant improvements in fracture strain. The link between microstructural processes and creep behaviour of pressed Cu and its selected alloys is examined in detail.
Trvalý link: http://hdl.handle.net/11104/0239608