High Temperature Creep of an Al-8,5Fe-1,3V-1,7Si Alloy

0177983 - UFM-A 20023107 RIV SK eng J - Journal Article
Kuchařová, Květa - Zhu, S. J. - Čadek, Josef
High Temperature Creep of an Al-8,5Fe-1,3V-1,7Si Alloy.
Kovové materiály. Roč. 40, č. 2 (2002), s. 69-84. ISSN 0023-432X. E-ISSN 1338-4252
R&D Projects: GA AV ČR IBS2041001
Institutional research plan: CEZ:AV0Z2041904
Keywords : Al-8,5Fe 1,3V 1,7Si alloy * creep behavior, true threshold stress
Subject RIV: JI - Composite Materials
Impact factor: 0.493, year: 2002

A previous investigation of creep behavior in an Al-8.5Fe-1.3V-1.7Si (8009AI type) alloy processed by rapid solidification and strengthened with small incoherent Al-12 (Fe,V)(3)Si phase particles, is extended to temperatures ranging from 773 to 923 K using the isothermal constant-stress-creep test technique. While in the temperature interval 623-723 K the creep behavior of the alloy is associated with the true threshold stress, at 773-923 K the true threshold stress is absent: the apparent stress exponent of minimum creep strain rate, m,, decreases with decreasing applied stress. Assuming a temperature independent value of the relaxation factor k(R) characterizing the strength of attractive dislocation/Al-12(Fe,V)(3)Si particle interaction, an attempt is made to interpret the minimum creep strain rate behavior in terms of the Rosler-Arzt model. The structure factor C following from the fitting procedure differs from that calculated from the structure data by a factor in average equal to 60. The activation energy of detachment of dislocations from interacting Al-12(Fe,V)(3)Si phase particles, following from the experimental creep data analysis, differs from that predicted by the model by a factor in average equal to 1.33. Thus, the thermally activated detachment of dislocations from the fine incoherent (interacting) particles is identified as the creep strain rate controlling process.
Permanent Link: http://hdl.handle.net/11104/0001559