Characterization of High Cycle Fatigue Behavior of a New Generation Aluminum Lithium Alloy (Preprint)
MISSOURI UNIV OF SCIENCE AND TECHNOLOGY ROLLA
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The high cycle fatigue life characteristics of an Al-Li alloy was studied as a function of microstructure. For the parent microstructure, fatigue life decreased with an increase in the grain size. No such effect was however noted at high stresses. This decrease in fatigue life was correlated with the lower crack initiation life arising due to small crack effect. Under multiaxial stress conditions, the alloy exhibited intergranular type of cracking. The cross-linking of intergranular cracks in T8 condition caused a further deterioration in fatigue life. Additionally, planar type of slip movements in T3 condition in stage-I crack propagation was observed. The slip planarity depended on both the sample texture and the nature of precipitates. Fractographic and textural evidences for this are presented.
- Metallurgy and Metallography