The effect of Ti addition on alloying and formation of nanocrystalline structure in Fe–Al system

In this work, the effect of Ti addition on alloying and formation of nanocrystalline structure in Fe–Al system was studied by utilizing mechanical alloying (MA) process. Structural and morphological evolutions of powder particles were studied by X-ray diffractometry, microhardness measurements, and scanning electron microscopy. In both Fe75Al25 and Fe50Al25Ti25 systems MA led to the formation of Fe-based solid solution which transformed to the corresponding intermetallic compounds after longer milling times. The results indicated that the Ti addition in Fe–Al system affects the phase transition during mechanical alloying, the final crystallite size, the mean powder particle size, the hardness value and ordering of DO3 structure after annealing. The crystallite size of Fe3Al and (Fe,Ti)3Al phases after 100 h of milling time were 35 and 12 nm, respectively. The Fe3Al intermetallic compound exhibited the hardness value of 700 Hv which is significantly smaller than 1050 Hv obtained for (Fe,Ti)3Al intermetallic compound.