Nanocrystalline τ2 phase obtained by mechanical alloying of Al60Fe15Si15Ti10 powder mixture followed by consolidation

In the present work an elemental powder mixture of Al60Fe15Si15Ti10 (at.%) was mechanically alloyed in a high-energy ball mill. A part of the milling product was examined in a calorimeter, while another portion was subjected to consolidation by hot-pressing at 1000 °C for 180 s under a pressure of 7.7 GPa. The results obtained show that a nanocrystalline cubic phase with the lattice parameter a0 = 11.645 Å, isomorphous with the τ2 (Al2FeTi) phase, is formed during mechanical alloying process. Heating of the milling product in the calorimeter up to 720 °C causes limited growth of grains, however the τ2 phase remains nanocrystalline with the mean crystallite size of 28 nm. Grain growth takes place during consolidation of the milling product as well, although the τ2 phase remains nanocrystalline with the mean crystallite size of 34 nm. The microhardness of the bulk nanocrystalline sample is 1013 HV0.2 and its open porosity is 0.3%. The results obtained show that the quality of compaction with preserving nanometric grain size of the τ2 phase is satisfactory and its microhardness is relatively high.