Bulk Fe2B crystal fabricated by mechanical ball milling and plasma activated sintering

Bulk Fe2B crystals were fabricated with Fe and B mixed powders by mechanical ball milling and plasma activated sintering (PAS). The results indicate that, as milling time reaches 10 h and above, the diffraction peaks of B powders will vanish and new phases will not appear. With increasing milling time from 1 h to 40 h, the distribution of mixed powders gradually becomes uniform and compact; however, at milling time from 40 h to 50 h, the uniformity and relative density have no distinct change. At sintering temperature of 1173 K, the phase compositions of sintered samples are composed of Fe3B and α-Fe. At 1273 K and 1373 K, bulk Fe2B can be fabricated and the relative density of these two samples has no distinct difference, except the difference of Fe2B sizes. In additional, compared with grain size at 1173 K. the grain sizes at 1273 K and 1373 K sharply become much bigger. Furthermore, due to the Fe2B size at 1373 K larger than that at 1273 K, Fracture toughness of Fe2B at 1273 K distinctly decreases from 3.96 MPa m1/2 to 3.01 MPa m1/2.