To solve thickness problem for high-strength aluminum alloy used as plastic mold materials and eliminate oxide film on the surface of aluminum alloy, a new compound casting, namely impact jet solid–liquid compound casting, was developed to fabricate 3A21/7075 aluminum alloy cladding material. Then, optical microscope (OM), electron-backscattered diffraction (EBSD) technique, and transmission electron microscope (TEM) together with energy-dispersive spectrometer (EDS) were used to analyze microstructure of 3A21/7075 aluminum alloy cladding material. The OM and EBSD results showed that the 3A21/7075 aluminum alloy cladding material was composed of 3A21 cladding layer, fusion zone (FZ), heat-affected zone, and 7075 matrix. The grain morphology on both sides of FZ had great differences. Moreover, the TEM and EDS results showed that the 3A21 cladding layer showed a bulk phase and lots of fine and dispersed granular phases, while the 7075 matrix appeared undetermined strip phases and amounts of fine and dispersed rod-like phases. Moreover, FZ existed a great deal of fine and dispersed granular phases and rod-like phases. The 3A21/7075 aluminum alloy cladding material could effectively solve the problems mentioned above and the in-depth analysis of microstructures of 3A21/7075 aluminum alloy cladding material was of great importance in terms of engineering value and academic significance.

为了解决用作塑料模具材料的高强度铝合金的厚度问题并消除铝合金表面的氧化膜，开发了一种新型复合铸件，即冲击射流固液复合铸件，以制造3A21 / 7075铝合金覆层材料。然后，使用光学显微镜（OM），电子反向散射衍射（EBSD）技术和透射电子显微镜（TEM）以及能量色散光谱仪（EDS）来分析3A21 / 7075铝合金熔覆材料的微观结构。OM和EBSD结果表明3A21 / 7075铝合金熔覆材料由3A21熔覆层，熔合区（FZ），热影响区和7075基体组成。FZ两侧的晶粒形态差异很大。而且，TEM和EDS结果表明，3A21熔覆层呈块状相，大量细小且分散的颗粒状相，而7075基体呈条状未确定，细小且分散的棒状相。而且，FZ存在大量细小且分散的颗粒相和棒状相。3A21 / 7075铝合金包覆材料可以有效地解决上述问题，深入分析3A21 / 7075铝合金包覆材料的微观结构在工程价值和学术意义上都具有重要意义。FZ存在大量细小且分散的颗粒相和棒状相。3A21 / 7075铝合金包覆材料可以有效地解决上述问题，深入分析3A21 / 7075铝合金包覆材料的微观结构在工程价值和学术意义上都具有重要意义。FZ存在大量细小且分散的颗粒相和棒状相。3A21 / 7075铝合金包覆材料可以有效地解决上述问题，深入分析3A21 / 7075铝合金包覆材料的微观结构在工程价值和学术意义上都具有重要意义。