2050铝合金厚板的晶间腐蚀行为研究

Research on Intergranular Corrosion Behavior of 2050 Aluminum Alloy Thick Plate

90 mm厚的2050铝合金热轧厚板的微观组织在厚度方向上的不均匀性导致其厚度方向的晶间腐蚀性能存在差异。采用电子背散射衍射(EBSD)技术对不同层的晶粒特征进行表征;采用透射电镜(TEM)观察试样的形貌。对试样的晶间腐蚀进行分析。通过EBSD技术揭示了不同层的晶间腐蚀性能与其微观组织状态之间的联系。结果表明:从表层到中心层,合金的晶粒尺寸逐渐增大。试样不同层的亚晶界存在T1(Al2CuLi)相富集现象。从表层到中心层,合金晶间腐蚀性能下降。

The inhomogeneity of the microstructure of 90 mm-thick 2050 aluminum alloy thick plate in the thickness direction leads to the difference of intergranular corrosion performance in thickness direction.The electron backscatter diffraction(EBSD)technology was used to characterize the grain characteristics of different layers.The transmission electron microscopy(TEM)was used to observe the morphology.The intergranular corrosion of the samples was analyzed.The relationship between the intergranular corrosion performance and the microstructure of different layers was revealed by EBSD technology.The results show that from the surface layer to the center layer,the grain size of the alloy gradually increases.The T1(Al2CuLi)phase enrichment phenomenon appears in the sub-grain boundaries of samples in different layers.The intergranular corrosion performance of the alloy decreases from the surface layer to the central layer.