HARDNESS MEASUREMENTS OF NANOPHASE AL AL-OXIDE CONSOLIDATED COMPOSITES/

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