密闭型腔中泡沫铝发泡行为

Foaming behavior of aluminum foam in closed cavity

为了分析泡沫铝复合结构件的制备工艺,研究了纯铝基泡沫铝在密闭型腔中的发泡行为.采用粉末冶金法,通过模压、热挤压与拉拔工艺制成所需规格的预制体,然后置入密闭型腔中保温发泡制得泡沫铝.结果表明:随着保温时间的增加,预制体渐渐充满型腔,泡体成型性较好,但在后期阶段出现大通孔和实铝层现象等缺陷.当发泡温度为700℃且直径为8.5 mm的预制体在其三倍体积密闭型腔中发泡时,可以制得泡孔结构相对均匀且稳定的泡沫铝.

In order to analyze the preparation processes of aluminum foam composite structure,the foaming behavior of pure aluminum-based aluminum foam in closed cavity was studied.The pre-fabricated structures with required specifications were prepared by means of powder metallurgy method including mold pressing,hot extrusion and drawing processes at first,then they were placed in a closed cavity for heat preservation to form aluminum foam.The results show that the pre-fabricated structures gradually fill up the cavity for the bubbles showing good formability with the increase of holding time,but the defects such as large holes and solid aluminum layer appear in the later stage.When the foaming temperature is set at 700℃and the pre-fabricated structures with a diameter of 8.5 mm is foamed in the closed cavity with a volume three times that of pre-fabricated structures,the aluminum foam with relatively homogeneous and stable pore structure can be obtained.