The creep properties of metal matrix composite(MMC) which is 10% silicon carbide particulate reinforced FVS0812(Al-8.5wt.% Fe-1.3wt.%V-1.7wt.%Si) alloy, produced by powder metallurgy, have been studied in 698-763K. The experimental data, which extend over several orders of magnitude of strain rate show that stress sensistivity parameter, m, is high and increase with decreasing the applied stress and that the apparent activation energy for creep, Qapp, is much higher than the activation energy for self diffusion in aluminum. The above creep characteristics of the composite are similar to those reported for dispersion strengthened alloys. But, the threshold stress models proposed for dispersion strengthened alloys, such as Orowan stress and detachment stress cannot explain satisfactorily the threshold stress of FVS0812/SiC composite. The stress sensistivity parameter atprimary creep region increase with decreasing applied stress as like steady state. The activation energy at primary creep region is more or less smaller than the activation energy for self diffusion in aluminum and increase with increasing creep deformation. This pheonomen can explain in terms of effective stress that participate in creep deformation by dislocation motion. It shows that the creep deformation of the composite is mainly controlled by plastic deformation of Al matrix. This viewpoint is consistent with observed dimpled fracture surface. Although the composite exhibited limited ductility on a macroscopic scale, fractography revealed that the fracture occured by a locally ductile manner.
