2A66铝锂合金板材各向异性研究

采用布氏硬度与拉伸性能测试以及OM,SEM和TEM分析,研究2A66铝锂合金板材力学性能的各向异性随时效时间变化的规律和合金时效状态下的显微组织,并探讨影响各向异性的主要因素。结果表明:165℃峰值时效前,随时效时间的延长,2A66铝锂合金力学性能的各向异性程度逐渐下降,过时效后合金的各向异性有所增强,伸长率的各向异性大于强度各向异性。峰时效(64h)时合金的σ_b,σ_(0.2),δ的IPA值均达到了最低值,分别为3.0%,3.0%,12.2%,此时合金也获得了较好的强塑性结合,轴向σ_b,σ_(0.2),δ分别为526.5,448.9MPa,10.1%。不同热处理状态下,2A66铝锂合金平面各向异性的总体表现为:纵向(0°)和横向(90°)的强度最高,45°方向最低;45°方向试样的伸长率最高,纵向和横向最低。

Anisotropy of 2A66 Al-Li Alloy Sheet

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.