Anisotropy of 2A66 Al-Li Alloy Sheet

Abstract

The anisotropy and microstructures during aging treatment for 2A66 Al-Li alloy were studied by Brinell hardness, tensile testing, optical microscope(OM), scanning electron microscope(SEM) and transmission electron microscope (TEM). The main factors which influence the anisotropy of mechanical properties were discussed. The results indicate that, before 165℃ peak-aged, the anisotropy of the mechanical properties of the 2A66 Al-Li alloy decreases gradually with the extension of aging time. When the alloy is over-aged, the anisotropy of the alloy increases; the anisotropy of ductility is more serious than that of strength. The IPA values of σb, σ0.2 and δ of the alloy reach the lowest value at 3.0%, 3.0% and 12.2% respectively at the time of peak aging (64h), and the alloy is also obtained with good plasticity and axial tensile properties. σb, σ0.2 and δ of the alloy are 526.5, 448.9MPa, 10.1% respectively. Under different heat treatment conditions, the general behavior of the anisotropy of 2A66 Al-Li alloy is as follows: longitudinal (0°) and transverse (90°) have the highest strength, 45° direction is the lowest strength; 45° direction specimen has the highest elongation, vertical and horizontal direction has the minimum elongation.

Keywords

• 2A66 Al-Li alloy
• mechanical property
• anisotropy
• aging treatment
• microstructure