Abstract: The liquid phase composite-rolling technology is used to prepare foamable preforms with different content of w_○Cu and closed-pore aluminum foams. The effect of w_○Cu on the pore structure of the aluminum foams was studied. The results show that with the increase of w_○Cu， the uniformity of 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 w_○Cu， it is found that when the w_○Cu 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 CuAl₂can be formed after adding Cu into AlSi₉ 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 AlSi₉ 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.

Key words: aluminum foam; liquid phase composite-rolling technology; Cu content; pore structure; expansion rate