Multiscale Investigation Of The Crystallization Mechanisms And Solute Redistribution During Annealing Of A Fe64b24y4nb6al0.4 Metallic Glass

The mechanisms and the sequence of crystallization of a Fe64B24Y4Nb6Al0.4 metallic glass were investigated experimentally. To this end, the microstructure of the metallic glass after interrupted isothermal treatments at a temperature between glass transition and primary crystallization was studied by complementary techniques, namely atom probe tomography, transmission electron microscopy and X-ray diffractometry. During the early stages of crystallization of the glass, some nanometric (Fe,Nb)B crystals nucleate first by rejecting Y at their interface, which hinders their growth. The Fe62B14Y3 dendritic phase starts growing in a second step. Longer annealings lead to the development of chemical gradients in the amorphous matrix surrounding Fe62B14Y3 crystals, which favors the nucleation of additional nanometric (Fe,Nb)(2.4)B crystals. (C) 2021 Elsevier B.V. All rights reserved.