Influence of milling conditions on the mechanical alloying of Fe-B powders

Amorphous and nanostructural Fe-B alloys made by mechanical alloying of ele mental Fe and amorphous B powders have been studied using X-ray diffraction , differential scanning calorimetry and Mossbauer spectroscopy. It has been shown that the milling conditions have a strong effect on the alloying. Th e single phase amorphous alloy, which is limited at nominal composition of Fe60B40, has been produced only by milling in Ar atmosphere and in other co mposition range the mixture of nanostructure Fe-like phase and Fe2B compoun d with a little amorphous phase are obtained. While by milling in air atmos phere the introduction of oxygen in air may suppress the formation of amorp hous phase, thus the compounds Fe2B may be synthesized with no trace of amo rphous phase. The crystallization temperatures of amorphous phase in the re sultant products are higher than those of a single amorphous alloy Fe60B40, and hardly independent of the milling conditions and the composition. In a ddition, it is revealed that detectable B content in the final products is lower than the nominal composition of all the initial samples, which indica tes that some B atoms may be located in the disordered interfacial regions of the nanostructural alloyed mixtures.