Effect of grain structure and precipitate on tensile properties and low-cycle fatigue behaviors of 2A55 Al-Cu-Li alloy

The tensile properties and cycle fatigue behaviors of 2A55 Al-Cu-Li alloy plates were assessed along the rolling direction (RD) and transverse direction (TD). The stronger anisotropy in elongation attributes to the grain boundary and crystallographic texture, and decreases as the formation of precipitation-free zones. The cyclic hardening is caused by the interaction between dislocations and dislocations or non-shearable precipitates. The non-shearable T-1 precipitates could be bypassed via dislocation cross-slip and then more multiple slip planes are activated, which causes more shearable precipitates could be cut, leading to the cyclic softening at higher strain amplitude.