Study on the Compression Stress-strain Behavior of Porous Al and Porous Al/Al₂O₃ Composite

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.