Nanocrystalline FeAl matrix composites reinforced with TiC obtained by hot-pressing consolidation of mechanically alloyed powders

Bulk FeAl matrix nanocomposites reinforced with 50%, 30% and 10% of TiC were produced by hot-pressing consolidation of mechanically alloyed nanocrystalline Fe(Al)–TiC composite powders containing different amounts of reinforcement. The powders were compacted at 1000 °C under a pressure of 7.7 GPa. Structural investigations of the consolidated materials revealed that transformation of the Fe(Al) solid solution into FeAl intermetallic had occurred during sintering and that both the matrix and the reinforcement remained nanocrystalline, with the mean crystallite size of about 20 nm. We infer that applying of a high pressure hinders grain growth at elevated temperature. The microhardness of the produced materials is relatively high, ranging between 1363 and 1608 HV0.2, depending on the amount of TiC. The density of the obtained bulk materials is very close to 100% of the “ideal” value and the open porosity is zero. These results as well as structural investigations show that the quality of compaction with preserving of the nanometric grain size of the composite constituents is satisfactory.