Cast Microstructure and Fatigue Behavior of a High Strength Aluminum Alloy (KO-1)

摘要

Microstructure and fatigue behavior were studied in sand-cast and end-chilled KO-1 high strength aluminum alloy. Secondary dendrite arm spacing and volume percent microporosity increase with distance from the chill, whereas colume percent interdendritic nonequilibrium secondary phase decreases. The fatigue life of the alloy at room temperature was measured in reversed bending on unnotched specimens at stress levels of 17,300 and 19,000 psi and was found to decrease with increasing distance from the chill.