航空用铝合金超微结构实验表征

为了使铝合金更好的服役于航空领域,就有必要对其微观结构进行实验表征,从而可以在铝合金微观结构和宏观性能之间搭建桥梁,最终优化铝合金的综合性能。本文介绍了航空用2xxx,6xxx和7xxx系铝合金发展历程以及时效析出过程中的微观结构演变,如Al-Cu合金GP区、Al-Cu-Mg合金GPB区等重要物相的结构特征,以及AlCu-Mg合金S相析出行为等都已得到了透彻的研究;阐述了透射电镜、扫描透射电镜、三维原子探针等技术的结合在Al-Cu-Mg-Ag合金Ω相、Al-Mg-Si-Cu合金β″相的晶体结构及界面结构以及铝合金晶间腐蚀机理等研究上的应用;本小组实现了复杂选区电子衍射谱的快速模拟及标定,并基于会聚束电子衍射实现了对析出相体积分数的精确测量;最后指出,高分辨透射电镜原位加热研究及透射电镜原位力学测试等新技术手段的应用,对深层次研究铝合金相变规律、变形行为具有跨时代意义。

Experimental Characterization of Ultrastructure of Aviation Aluminum Alloys

In order to improve the comprehensive performance of aluminium alloys for the aviation application, it is necessary to experi-mentally characterize the microstructure, and thus to build a bridge between the microstructure and macro-performance of aluminum al-loys. This paper introduces the brief developing course of 2xxx, 6xxx and 7xxx aluminum alloys and their microstructure evolution dur-ing artificial aging . The structural characteristics of significant phases like GP zones in Al-Cu alloys and GPB zones in Al-Cu-Mg al-loys, and the precipitation behavior of S phase in Al-Cu-Mg alloys, etc, are thoroughly studied. The application of Transmission Elec-tron Microscopy, Scanning-Transmission Electron Microscopy, 3-Dimentional Atom Probe in the investigations of structure, morpholo-gy, composition, interface structures, intergranular corrosion resistance and so on has been reviewed, especially theΩphase in Al-Cu-Mg-Ag alloys andβ″phase in Al-Mg-Si-Cu alloys. Our group has finished the works such as the simulation and characterization of com-plex selected area electron diffraction patterns in Al alloys, as well as the measuring of the precipitates’ volume fraction with high accu-racy which is based on the convergent beam electron diffraction.