Effects of microstructure on tensile properties of AA2050-T84 Al−Li alloy  

显微组织对AA2050-T84铝锂合金拉伸性能的影响

作　　者：Ding-ding LU Jin-feng LI Hong NING Peng-cheng MA Yong-lai CHEN Xu-hu ZHANG Kai ZHANG Jian-mei LI Rui-feng ZHANG 陆丁丁;李劲风;宁红;马鹏程;陈永来;张绪虎;张恺;李建梅;张瑞丰(中南大学材料科学与工程学院,长沙410083;航天材料及工艺研究所,北京100076;Monash Centre for Additive Manufacturing,Monash University,Clayton 3800,Australia;宁夏大学化学化工学院,银川750021)

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]Aerospace Research Institute of Materials and Processing Technology,Beijing 100076,China [3]Monash Centre for Additive Manufacturing,Monash University,Clayton 3800,Australia [4]School of Chemistry and Chemical Engineering,Ningxia University,Yinchuan 750021,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第5期1189-1204,共16页中国有色金属学报（英文版）

基　　金：the National Natural Science Foundation of China(No.51961034);the Key Research and Development Program of Ningxia(No.2018BEB04037),China.

摘　　要：The effect of microstructure evolution on the tensile properties of 2050 Al-Li alloy thick plate aged at 150 ℃ with 80 mm in thickness(t) was studied from a microstructural perspective. Scanning electron microscope, optical microscope, transmission electron microscope and X-ray diffractometer were used to explore the surface(t/6), interlayer(t/3) and center(t/2) thickness layer of this alloy. Results show that the secondary phases on grain boundaries, precipitates and textures vary depending on the thickness location. The precipitation strengthening has a stronger influence on the alloy along the rolling direction than the transverse direction from the under-aged to the peak-aging condition;however, its effect on the anisotropy is insignificant. The higher Taylor factor(M) value caused by stronger β fiber rolling textures and the intergranular phases is the main reason that leads to the highest strength at the t/2 position along the rolling direction. The M-value has a limited change at different thickness layers along the transverse direction, which causes the same tensile strength.从显微角度研究80 mm厚(t)2050铝锂合金板材在150℃时效后显微组织对其拉伸性能的影响。采用扫描电子显微镜、光学显微镜、透射电子显微镜和X射线衍射仪对合金表层(t/6)、中间层(t/3)和中心层(t/2)进行观察。结果表明,合金晶界第二相、析出相和织构随厚度位置的变化而出现差异。在欠时效到峰时效过程中,该合金沿轧制方向的析出相强化效果高于沿垂直轧制方向,但对合金各向异性影响不显著。β织构导致的较高泰勒因子值以及晶间第二相是合金在t/2层沿轧制方向获得最高强度的主要原因。合金沿垂直轧制方向的泰勒因子值差别较小,这导致合金在不同厚度层有相同抗拉强度。

关 键 词：2050 Al−Li alloy tensile properties ANISOTROPY PRECIPITATE texture 

分 类 号：TG146.21[一般工业技术—材料科学与工程]