New observations on high temperature creep at very low stresses
New observations on high temperature creep at very low stresses
Creep tests were conducted in compression to evaluate the flow behavior of aluminum at very high temperatures and low stresses. The experiments used two types of specimens: single crystals of 99.999% purity and oligocrystalline samples of 99.97% purity. Results obtained for the single crystals lie consistently between the conventional region of Harper–Dorn creep and the anticipated behavior based on an extrapolation of conventional 5-power creep. Using etch pit studies with the single crystals, it is shown there is no evidence for subgrain formation and the measured dislocation densities are consistent with data extrapolated from the conventional 5-power region. The creep results on single crystals suggest the stress exponent is close to ~3 at low stresses. It is demonstrated these results are consistent with earlier data including the results of Harper and Dorn when their data are plotted in terms of the true applied stress without incorporating a threshold stress.
aluminum, creep mechanisms, dislocation density, harper–dorn creep, stress exponent
20-24
Kumar, Praveen
6061332b-68e8-46ec-92ce-8ec6025748af
Kassner, Michael E.
44ea4d79-4e98-4160-b3d4-40335133fe9a
Blum, Wolfgang
39f96c4a-2818-4f21-ac89-18eb32f0ca19
Eisenlohr, Philip
8ac81d2c-9a93-42f3-bc44-bcf613d106de
Langdon, Terence G.
86e69b4f-e16d-4830-bf8a-5a9c11f0de86
15 June 2009
Kumar, Praveen
6061332b-68e8-46ec-92ce-8ec6025748af
Kassner, Michael E.
44ea4d79-4e98-4160-b3d4-40335133fe9a
Blum, Wolfgang
39f96c4a-2818-4f21-ac89-18eb32f0ca19
Eisenlohr, Philip
8ac81d2c-9a93-42f3-bc44-bcf613d106de
Langdon, Terence G.
86e69b4f-e16d-4830-bf8a-5a9c11f0de86
Kumar, Praveen, Kassner, Michael E., Blum, Wolfgang, Eisenlohr, Philip and Langdon, Terence G.
(2009)
New observations on high temperature creep at very low stresses.
Materials Science and Engineering: A, 510-511, .
(doi:10.1016/j.msea.2008.04.094).
Abstract
Creep tests were conducted in compression to evaluate the flow behavior of aluminum at very high temperatures and low stresses. The experiments used two types of specimens: single crystals of 99.999% purity and oligocrystalline samples of 99.97% purity. Results obtained for the single crystals lie consistently between the conventional region of Harper–Dorn creep and the anticipated behavior based on an extrapolation of conventional 5-power creep. Using etch pit studies with the single crystals, it is shown there is no evidence for subgrain formation and the measured dislocation densities are consistent with data extrapolated from the conventional 5-power region. The creep results on single crystals suggest the stress exponent is close to ~3 at low stresses. It is demonstrated these results are consistent with earlier data including the results of Harper and Dorn when their data are plotted in terms of the true applied stress without incorporating a threshold stress.
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More information
Published date: 15 June 2009
Additional Information:
11th International Conference of Creep and Fracture of Engineering Materials and Structures, CREEP 2008
Keywords:
aluminum, creep mechanisms, dislocation density, harper–dorn creep, stress exponent
Organisations:
Engineering Mats & Surface Engineerg Gp
Identifiers
Local EPrints ID: 67631
URI: http://eprints.soton.ac.uk/id/eprint/67631
ISSN: 0921-5093
PURE UUID: a1ca1c2f-5211-49f5-b213-90025bdca498
Catalogue record
Date deposited: 28 Aug 2009
Last modified: 14 Mar 2024 02:47
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Contributors
Author:
Praveen Kumar
Author:
Michael E. Kassner
Author:
Wolfgang Blum
Author:
Philip Eisenlohr
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