Anomalous high temperature creep behaviour of an Al-8.5Fe-1.3V-1.7Si (8009Al type) alloy reinforced with alumina short fibres

0178187 - UFM-A 20043006 RIV SK eng J - Journal Article
Čadek, Josef - Kuchařová, Květa
Anomalous high temperature creep behaviour of an Al-8.5Fe-1.3V-1.7Si (8009Al type) alloy reinforced with alumina short fibres.
Kovové materiály. Roč. 42, č. 1 (2004), s. 9-20. ISSN 0023-432X. E-ISSN 1338-4252
R&D Projects: GA AV ČR IBS2041001
Institutional research plan: CEZ:AV0Z2041904
Keywords : High temperature creep- load transfer
Subject RIV: JI - Composite Materials
Impact factor: 1.056, year: 2004

Creep in an Al-8.5Fe-1.3V-1.7Si (8009Al type) alloy dispersion strengthened with fine Al-12(Fe,V)(3)Si phase particles at temperatures 798-848 K is not associated with a true threshold and the same holds for the Alloy reinforced with alumina short fibres. While the true activation energy of creep in the Alloy is higher than the activation enthalpy of lattice self-diffusion in aluminium due to the energy of athermal detachment of dislocations from dispersed particles, this is not the case of the Composite. The true activation energy of creep in the latter is anomalously low and the creep behaviour cannot be described by the creep equation that holds for the Alloy, but contains the factor by which the flow stress in the dispersion strengthened matrix is reduced due to load transfer. Nevertheless, the creep strength of the Composite is, at the certain conditions at least, by a factor up to six orders of magnitude higher than that of the Alloy. This creep strength increment due to alumina short fibre reinforcement is accounted for in terms of the load transfer effect.
Permanent Link: http://hdl.handle.net/11104/0001572