2397铝锂合金显微组织、拉伸性能和断裂韧性研究  

Microstructure, Tensile Property and Fracture Toughness of 2397 Al-Li Alloy

作　　者：范春平[1] 郑子樵[1] 贾敏[1] 钟继发[1] 程彬[1] 李红萍[2] 吴秋萍[2] 

机构地区：[1]中南大学有色金属材料科学与工程教育部重点实验室,湖南长沙410083 [2]上海飞机设计研究院,上海200232

出　　处：《稀有金属材料与工程》2015年第1期91-96,共6页Rare Metal Materials and Engineering

摘　　要：通过金相显微镜、透射电镜和扫描电镜观察以及X射线织构测量、拉伸试验和平面应变断裂韧性测试,研究了130 mm厚2397-T87铝锂合金不同厚度层及不同取向的微观组织、拉伸性能和断裂韧性。结果表明:厚度方向织构分布不均匀,表层织构以高斯织构为主,中心织构则主要由β取向轧制织构和少量立方织构组成,亚表层T/8处织构较弱,且从中心到亚表层,β取向织构和立方织构含量降低,剪切织构含量增加,T/8处剪切织构含量最大。L方向不同厚度层拉伸性能具有不均匀性,亚表层的抗拉强度(σb)和屈服强度(σ0.2)小于中心,LT方向拉伸性能差异相对较小;同一厚度处,合金强度和断裂韧性具有各向异性,σb、σ0.2的变化规律为:L方向﹥LT方向﹥SL方向,L-T取向的断裂韧性最好,T-L取向次之,S-L取向最差。The microstructure, tensile property and fracture toughness of 2397-T87 Al-Li alloy plate were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, tensile and plane-strain fracture toughness tests. The results show that a pronounced texture variation through the plate thickness is found. Near the surface, Goss texture is dominating. While in the center of the plate, typical β fiber texture and a scattering of cube texture are observed. And the subsurface layer exhibits a very weak texture. From the center to the subsurface, the fraction of β fiber texture and cube texture decreases; in contrast, the fraction of shear type texture reaches the maximum in subsurface layer. The tensile properties in different layers along the thickness direction are inhomogeneous. The strength near the surface is lower than that in the center. And the through-thickness strength properties variation in the rolling direction is more remarkable than that in the long transverse direction. In the same thickness layer, the fracture toughness and the strength are anisotropic. The strength in the rolling direction is higher than that in the long transverse direction and the short transverse direction, and the strength in the short transverse direction is the lowest. The fracture toughness in L-T orientation is the highest, followed by that in T-L orientation, and the fracture toughness in S-L orientation is the lowest.

关 键 词：2397铝锂合金 织构 拉伸性能 断裂韧性 

分 类 号：TG146.21[一般工业技术—材料科学与工程]