Al(13)Fe(4)-Al Composites with Nanocrystalline Matrix Manufactured by Hot-Pressing of Milled Powders

The paper describes composites with the matrix containing a nanocrystalline intermetallic Al(13)Fe(4) phase and microcrystalline aluminium. Mechanically alloyed Al(80)Fe(20) powder, containing a metastable nanocrystalline Al(5)Fe(2) phase, was mixed with 20, 30, and 40 vol.% of Al powder and consolidated at 750 °C under the pressure of 7.7 GPa. During the consolidation, the metastable Al(5)Fe(2) phase transformed into a nanocrystalline Al(13)Fe(4) phase. In the bulk samples, Al(13)Fe(4) areas were wrapped around by networking Al regions. The hardness of the Al(13)Fe(4)-Al composites was in the range of 4.52–5.50 GPa. The compressive strength of the Al(13)Fe(4)-30%Al and Al(13)Fe(4)-40%Al composites was 805 and 812 MPa, respectively, and it was considerably higher than that of the Al(13)Fe(4)-20%Al composite (538 MPa), which failed in the elastic region. The Al(13)Fe(4)-30%Al and Al(13)Fe(4)-40%Al composites, in contrast, showed some plasticity: namely, 1.5% and 9.1%, respectively. The density of the produced composites is in the range of 3.27–3.48 g/cm(3) and decreases with the increase in the Al content.