Abstract: The progress of fatigue research for Al-Li alloys is summarized. The behavior of long and short fatigue cracks, the crack initiation of smooth and notched specimens, the cyclic strain response, the overload effect, the fatigue behavior at cryogenic temperatures and corrosion fatigue of Al-Li alloys are discussed. The comparison of behavior between Al-Li alloys and traditional Al alloys 2000 and 7000-series, the influence of heat treatment, the microstructure and chemical composition on fatigue behavior for Al-Li alloys are presented. The mechanism of crack tip shielding is interpreted in detail. The superior growth resistance of long fatigue cracks for Al-Li alloys is considered to be derived primarily from the crack tip shielding. Because the shielding effect is very sensitive to extrinsic condition, so Al-Li alloys show higher short crack effect, higher anisotropy, larger stress ratio effect and more sensitive overload effect.

Key words: Al-Li alloys, fatigue, performace effect