The effect of compaction temperature and pressure on the pores in nanostructured metal compacts prepared by magnetic pulsed compaction

The pore behavior of nano Al compacts prepared by magnetic pulsed compaction in a temperature range from 20°C to 300°C and under pressure of 0.7 and 1.6 GPa was studied by small angle neutron scattering (SANS) analysis. The size distribution and volume fraction of pores in the compact were determined by corrected scattering curves using a direct model fitting, under the assumption that the pores were spherical in shape. The densities obtained from the SANS analysis were well matched with those of direct measurement in the range of 76–95% of theoretical density. As the compaction temperature increased from 20°C to 300°C, the size of pores increased from 1.69 to 2.31 nm; however, the number of pores decreased from 169 to 71 (1/cmÅ2) in the case of 1.6 GPa compaction pressure. As a result, the density increased as the compaction temperature increased.