Processing and pore structure of aluminium foam sandwich
Processing and pore structure of aluminium foam sandwich
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DOI：
10.1016/j.powtec.2015.01.066
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发表时间：
2015-05
影响因子：
5.2
通讯作者：
Yao-qi Wang;X. Ren;H. Hou;Yanling Zhang;Wen-Li Yan
中科院分区：
文献类型：
--
作者：
Yao-qi Wang;X. Ren;H. Hou;Yanling Zhang;Wen-Li Yan
采用改进的粉末压块熔炼法（粉末包轧制熔炼法）制备了泡沫铝夹层结构。利用阿基米德原理研究了还原过程对前驱体相对密度的影响。测定了前驱体的发泡行为和孔结构。结果表明，随着压下量的增加，前驱体的相对密度增加，前驱体的均匀性也得到改善。最佳压下量为80%，因为当压下量大于80%时，相对密度及其分布几乎不变。发泡过程可分为成孔、孔生长和孔破裂三个阶段。在阶段II期间，前体的膨胀因子达到最大值2.37。不同阶段孔壁的微观结构有所不同。在第二阶段和第三阶段，组织演变为枝晶组织和共晶相，这与铸造AlSi 12合金的变质组织相似。
Aluminium foam sandwich had been prepared by modified powder compact melting process (powder pack rolling melting process). During the process, the effect of reduction on relative density of the precursor was studied by Archimedes' principle. The foaming behaviour and pore microstructure of precursor were determined. It is found that with the reduction increasing, the relative density of the precursor increases and the uniformity of the precursor can also get improved. The optimized reduction is 80% because the relative density and its distribution hardly change when the reduction is larger than 80%. The foaming process can be divided into three stages, pore forming, pore growing and pore cracking. During the stage II, the expansion factor of the precursor reaches a maximum 2.37. The microstructure of pore wall varies at different stages. At the second stage and third stage, the microstructure evolves into dendritic structure and eutectic phase, which is similar to the modified microstructure of cast AlSi12alloy.