用粉末烧结法制备出了开孔型多孔铝及以Al2O3为增强相的铝基多孔复合材料,材料相对密度及孔径分别在0.25~0.40和100~400 μm范围内变化.对这两种多孔材料的压缩行为进行了研究.结果表明:Al/Al2O3复合材料有着比多孔铝更为有利的响应特征和更高的流动应力,该复合材料的压缩应力-应变曲线较为平坦,在与多孔铝相对密度相近时,屈服强度提高40%以上;经T6热处理,Al/Al2O3复合材料的屈服强度可进一步提高35%左右;此外,该复合材料的压缩行为具有明显的孔径依赖性,随孔径增大,流动应力升高,这主要与烧结过程中孔表面残留的气体有关.

An open cell porous Al and Al/Al2O3 composite were fabricated by powder sintering technique.The relative density and pore size of resulted specimens can be changed in the ranges of 0.25-0.40 and 100-400 μm,respectively.The compression experiments were conducted and the results show that the porous Al/Al2O3 composite has a more beneficial response feature and higher flow stress than the porous Al.The former shows a relatively smooth plateau and when the relative densities of the two porous materials are approximately the same,the porous composite shows a 40% elevation relative to the porous Al,which can be further enhanced by T6 heat treatment that leads to around 35% increase.In addition,the stress-strain behavir of the porous composite shows significant pore size dependence,i.e.the flow stress increases with increasing the pore size,which is believed to be related to trapped gas in the pore surface during the sintering.