The 7075 aluminum alloy was an important structural material in the field of aeronautics and astronautics. With the development of this field, the requirements for its comprehensive properties were increasing. A novel casting method, the impact jet solid-liquid compound casting, was adopted to fabricate the 3A21/7075 aluminum alloy cladding material. Retrogression and reaging (RRA) treatment was further applied to the 3A21/7075 aluminum alloy cladding material in order to investigate the influence of RRA on microstructure and microhardness of the 3A21/7075 aluminum alloy cladding material. Then, the electron backscattered diffraction (EBSD) technique and the transmission electron microscope (TEM) together with the energy dispersive spectrometer (EDS) and the hardness test were utilized to analyze the influence of RRA treatment on microstructure and hardness of the 3A21/7075 aluminum alloy cladding material. The research results showed the 3A21/7075 aluminum alloy cladding material had better deformability. The amount of fine and dispersed phases precipitated in grains was in favor of improving the comprehensive mechanical properties of the 3A21/7075 aluminum alloy cladding material. This research might provide data and a theoretical approach for the engineering application of the 3A21/7075 aluminum alloy cladding material.

中文翻译：

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回归和时效处理对3A21 / 7075铝合金熔覆材料组织和显微硬度的影响

7075铝合金是航空航天领域的重要结构材料。随着该领域的发展，对其综合性能的要求越来越高。采用一种新颖的铸造方法，即冲击射流固液复合铸造法来制造3A21 / 7075铝合金覆层材料。为了研究RRA对3A21 / 7075铝合金熔覆材料的组织和显微硬度的影响，还对3A21 / 7075铝合金熔覆材料进行了回归和时效处理（RRA）处理。然后，利用电子背散射衍射（EBSD）技术，透射电子显微镜（TEM），能量色散谱仪（EDS）和硬度测试，分析了RRA处理对3A21 / 7075铝合金熔覆层组织和硬度的影响。材料。研究结果表明3A21 / 7075铝合金包覆材料具有较好的变形性能。在晶粒中沉淀的细相和分散相的数量有利于改善3A21 / 7075铝合金熔覆材料的综合机械性能。该研究可为3A21 / 7075铝合金熔覆材料的工程应用提供数据和理论方法。研究结果表明3A21 / 7075铝合金包覆材料具有较好的变形性能。在晶粒中沉淀的细相和分散相的数量有利于改善3A21 / 7075铝合金熔覆材料的综合机械性能。该研究可为3A21 / 7075铝合金熔覆材料的工程应用提供数据和理论方法。研究结果表明3A21 / 7075铝合金包覆材料具有较好的变形性能。在晶粒中沉淀的细相和分散相的数量有利于改善3A21 / 7075铝合金熔覆材料的综合机械性能。该研究可为3A21 / 7075铝合金熔覆材料的工程应用提供数据和理论方法。