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The liquid phase composite — rolling technology is used to prepare foamable preforms with different content of wCu and closed-pore aluminum foams. The effect of wCu, on the pore structure of the aluminum foams was studied. The results show that with the increase of wCu, the uniformity lot' the pore structure increases, and the pore size and the number of large pores produced by pore merging decrease, while the collapsing and aging characteristics of the foam are enhanced. After comparing the expansion curves of preforms with different wCu, it is found that when the wCu, increases, the maximum expansion rate of the preform firstly increases and then decreases and the foaming time to reach the maximum expansion rate is greatly shortened. The microstructure analysis shows that CuAl2O4 and CuAl2 can be formed after adding Cu into A1Si9 alloy. CuAl2O4 increases the viscosity of the melt, reduces the effect of gravity drainage and capillary action, and improves the stability of the foam. CuAl2 melts prior to A1Si9 alloy, forming a molten pool on the grain boundary, and the bubbles nucleate and grow in advance, so that the foaming process is completed ahead of schedule. [ABSTRACT FROM AUTHOR]

Closed-cell aluminum foam with different amounts of Mg and carbon fiber were prepared by the method of molten body transitional foaming process， and the effect of Mg element on foaming process and pore structure of aluminum foams was discussed. The main results are as follows: when the addition of Mg element increases， the expansion rate of foam increases significantly and the range of the pore size distribution becomes broader， associated with the increasing number of small stomata. The microstructures of the inner and surface of the pore wall show that the pore wall can be smoother， thinner and more stable after adding Mg， because the surface tension of molten aluminum is reduced， the wettability between aluminum and oxide particles is improved and the gas release during the foaming process increases. As a result of Mg addition， it is achieved that the porosity of aluminum foam can be more than 90%. [ABSTRACT FROM AUTHOR]