Al13Fe4-Al Composites with Nanocrystalline Matrix Manufactured by Hot-Pressing of Milled Powders

The paper describes composites with the matrix containing a nanocrystalline intermetallic Al13Fe4 phase and microcrystalline aluminium. Mechanically alloyed Al80Fe20 powder, containing a metastable nanocrystalline Al5Fe2 phase, was mixed with 20, 30, and 40 vol.% of Al powder and consolidated at 750 degrees C under the pressure of 7.7 GPa. During the consolidation, the metastable Al5Fe2 phase transformed into a nanocrystalline Al13Fe4 phase. In the bulk samples, Al13Fe4 areas were wrapped around by networking Al regions. The hardness of the Al13Fe4-Al composites was in the range of 4.52-5.50 GPa. The compressive strength of the Al13Fe4-30%Al and Al13Fe4-40%Al composites was 805 and 812 MPa, respectively, and it was considerably higher than that of the Al13Fe4-20%Al composite (538 MPa), which failed in the elastic region. The Al13Fe4-30%Al and Al13Fe4-40%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.

Automated summary

The paper describes a composite material with a matrix containing a nanocrystalline intermetallic phase Al13Fe4 and microcrystalline aluminium. The material was synthesized at a high temperature and pressure, and a phase transformation of the nanocrystalline phase was observed. The resulting composite material has high hardness and compressive strength, while also exhibiting some plasticity.