Mechanical alloying of Fe-B

Abstract

Fe-B alloys in both a nanostructural state and a disordered amorphous-like state have been produced using a novel ball-mill method. Mossbauer measurements at room temperature and 4.2 K on materials of nominal starting compositions Fe80B20 to Fe40B60 combined with X-ray diffraction and differential scanning calorimetry, revealed that samples with low B-content (<or approximately=34 at.% B) were formed mainly in a nanostructural state while samples with high B-content (>or approximately=50 at.% B) formed primarily in an amorphous-like state. The detectable B content of the mechanically alloyed samples was found to be lower than the nominal composition for all samples. The presence of unreacted B was confirmed by annealing experiments in which the expected fractions of phases alpha -Fe, Fe2B and FeB were obtained as crystallization products. In the samples, which partially exhibit a nanostructural state, B seems to be present only in the disordered interfacial regions.