Hardness measurements of nanophase Al/Al-oxide consolidated composites

Materials with grain sizes less than 100 nm, called nanophase materials, typically exhibit large changes in their physical properties. This work reports hardness measurements for composites made by consolidation of nanoscale aluminum particles which have been exposed to air. The results presented here point to a low density high strength material with significant porosity. A general trend of increasing hardness with decreasing grain size is also indicated. Some of the smaller grained samples show an increase in hardness with an accompanying decrease in mass density with increasing consolidation pressure. (C) 1997 Acta Metallurgica Inc.