| The cyclic creep behavior of Al-Zn alpha solid solution alloys (20, 30, 35, 40 & 60 at.% Zn) under repeated tension loading at 633°K is investigated. The experimental results are showing that the creep rate under repeated loading is lower than that of static loading at the same temperature. The stress exponent value for both cyclic and static creep is observed to be about 3 except for the 60 at.% Zn composition. These results indicate that the fundamental microcreep mechanism of the static and cyclic creep is probably same for the Al-Zn system. The most important experimental observation in this study is that the UTS at the elevated temperature influences on the cyclic creep strength of Al-Zn solid solution alloys. The larger the UTS, the higher creep strength of the Al-Zn alloys, and the UTS and cyclic creep strength have a correlation of σ_c∝σ_u^½ for the same value of ε˙/D. From this relation, the empirical cyclic creep equation can he obtained as follow, ε˙=KD(σ_c/σ_u^½)ⁿ |
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