INFLUENCE OF ECAP TECHNIQUE ON CREEP BEHAVIOUR OF POWDER ALUMINIUM PROCESSED BY DIRECT EXTRUSION

0351485 - ÚFM 2011 RIV CZ eng C - Conference Paper (international conference)
Dvořák, Jiří - Král, Petr - Balog, M. - Simančík, F. - Sklenička, Václav
INFLUENCE OF ECAP TECHNIQUE ON CREEP BEHAVIOUR OF POWDER ALUMINIUM PROCESSED BY DIRECT EXTRUSION.
Nanocon 2010. Ostrava: Tanger Ltd, 2010, s. 1-6. 1st edition. ISBN 978-80-87294-18-5.
[NANOCON 2010. International Conference /2./. Olomouc (CZ), 12.10.2010-14.10.2010]
R&D Projects: GA AV ČR(CZ) KJB200410801
Institutional research plan: CEZ:AV0Z20410507
Keywords : powder aluminium * CREEP * ECAP * ultrafine-grained material
Subject RIV: JJ - Other Materials

The Al powder was prepared by cold isostatic pressing at the pressure of 200 MPa. The granulometric powder fraction of a particle size less than 400 µm was compacted via conventional direct hot-extrusion (DE) at temperature 450°C. This material was then subjected to ECAP technique up to 4 passes. The microstructural investigations were performed using OM and SEM equipped with an EBSD unit. Creep tests in tension were conducted at temperature of 473 K and at applied stresses in the range from 30 to 60 MPa. Some creep tests in compression were performed on material just after DE. The paper presents results of study of microstructure and creep behaviour of aluminium powder before and after ECAP. It was found that ECAP method does not lead to an additional marked refinement of grain size. However, in dependence on number of ECAP passes ECAP method markedly influences creep behaviour due to development of high-angle grain boundaries during ECAP process.
Permanent Link: http://hdl.handle.net/11104/0191225