以3003M铝合金的化学成分为基础，通过正交试验研究了锰、硅、锌、铜，以及富铈混合稀土含量对铝合金室温力学性能和高温抗下垂性能的影响，优化了复合铝箔芯材铝合金的化学成分，并分析了铝合金在钎焊过程中的抗下垂机制。结果表明：铜元素对试验铝合金抗拉强度的影响最大，硅、锰、铜元素对高温抗下垂性能的影响较显著；性能最优铝合金中铜、锌、硅、锰，以及富铈混合稀土的质量分数分别为0.5%，2.5%，0.8%，1.2%，0，最优铝合金的抗拉强度比3003M铝合金的高约40 MPa，伸长率高约2个百分点，下垂距离缩短一半；在610℃钎焊过程中，优化铝合金出现二次再结晶现象，组织由弥散分布的析出相、一次再结晶晶粒和尺寸约1 mm的粗大长条晶粒组成。

The effects of content of Mn, Si, Zn, Cu and Ce-rich mixed rare earth on the room-temperature mechanical properties and high temperature sagging resistance of the aluminum alloy on the basis of chemical composition of 3003M aluminum alloy were studied by orthogonal test. The chemical composition of aluminum alloy core material for composite aluminum foil was optimized and the sagging resistance mechanism of the aluminum alloy during brazing was analyzed. The results show that Cu element had the greatest effect on the tensile strength of the tested aluminum alloy, while Si, Mn and Cu elements had significant effects on the sagging resistance. The mass fractions of Mn, Si, Zn, Cu and Ce-rich mixed rare earth of the aluminum alloy with the best properties were 0.5%, 2.5%, 0.8%, 1.2%, 0, respectively. The tensile strength of the optimal aluminum alloy was about 40 MPa higher than that of 3003M aluminum alloy, the elongation increased by about 2 percentage points, and sagging distance was shortened by half. During brazing at 610℃, the secondary recrystallization occurred in the optimal aluminum alloy, and the microstructure was composed of dispersed precipitated phase, primary recrystallization grains and coarse long grains with size of about 1 mm.