Effect of hold time periods at high temperature on fatigue life in aluminum alloy 2024 t4

Abstract EN

In some applications, the aluminum alloy 2024 T4 may be subjected to an interaction of fatigue and creep effects at high temperature.

This paper investigates the effect of this interaction by studying the effect of constant amplitude fatigue (CAF) and creep separately, and then fatigue-creep interaction is introduced by testing the alloy under constant amplitude with some holding time periods through the test at high temperature (150 oC).

The results showed that the life time of the alloy decreases due to fatigue-creep interaction as compared to creep alone in about 77%, and in about 80% as compared with fatigue alone.

This is a result of accumulated fatigue damage superimposed on creep damage.

Creep allows more free spaces for fatigue cracks paths that accelerate failure.

A theoretical model to calculate the time to failure due to fatigue-creep interaction has been proposed.

This theoretical interaction model predicts very close time to failure values to the experimental results.