High-temperature creep behavior of SiC particulate reinforced AlFeVSi alloy composite

A 15vol.%SiC particulate reinforced Al–8.5Fe–1.3V–1.7Si (8009Al) composite and unreinforced monolithic alloy were subjected to creep tests at 723–823 K. High and variable apparent stress exponent and apparent activation energy for creep were observed for both the composite and monolithic alloy. The reinforced and unreinforced 8009Al alloys exhibited an almost identical creep resistance in the stress and temperature ranges investigated, indicating that the SiC particulates exert no strengthening effect on the 8009Al alloy at elevated temperatures. By incorporating a threshold stress into the power law creep equation, the creep data of both reinforced and unreinforced 8009Al alloys were analyzed. The threshold stress obtained by the extrapolation technique exhibits a strong temperature dependence. The calculated values of the apparent stress exponent and apparent activation energy were in good agreement with those obtained from the experimentally determined ε̇T, σ relationships.