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A study was conducted to determine how the fatigue life of a 319 aluminum alloy (W319) was affected by pore size. To perform this study, two sets of microstructurally similar castings with differing levels of microporosity were created. Following room temperature fatigue testing, the pores that initiated fatigue cracks were identified and quantified. The results indicate that doubling the average initiating pore diameter yielded an approximate 30% decrease in run-out stress in the W319-T7 aluminum alloy.

The automotive use of cast aluminum has greatly increased during the past decade, especially for engine blocks and cylinder heads. One physical property that is important in elevated-temperature applications is long-term dimensional stability of the cast aluminum component. Certain cast aluminum alloys (like 319) can undergo dimensional changes when exposed to engine operating temperatures over long periods of time; when these changes occur, the shape of the casting is distorted and the performance of the component may be diminished. Thus, a study was conducted to measure dimensional growth changes in a cast 319-type aluminum alloy as a function of heat-treatment, exposure temperature, and exposure time at the given temperature. The results show that all three factors have a significant effect upon the dimensional stability.