Crystallization kinetics of Pr8Fe86-xZrxB6 (x=0, 1, 2) amorphous alloys was studied by DTA and XRD methods. The experimental results showed that the crystalline phases of Pr8Fe86B6 alloy are composed of α-Fe phase, Pr2Fe23B3 and Pr2Fe14B, when crystallization temperature is below 900 ℃. The activation energy of α-Fe phase remains relatively constant about 306.09 kJ/mol, as the crystalline fraction of α-Fe phase is below 8 %. At the beginning of crystallization, the activation energy of Pr2Fe23B3 and Pr2Fe14B phases are 510.85 kJ/mol and 725.97 kJ/mol, respectively, and then the activation energy of three phases declines with increasing the crystalline fraction. The crystallization behavior of α-Fe and Pr2Fe14B essentially results in the formation of a α-Fe/Pr2Fe14B composite microstructure with a coarse grain size in annealed Pr8Fe86B6 alloy, which is attributed to a difficult nucleation and an easy growth for both the α-Fe and Pr2Fe14B in the alloy. Zr can be used to change the crystallization behavior of the α-Fe phase in Pr-Fe-B amorphous alloy, which is helpful to the formation of the α-Fe/Pr2Fe14B nanocomposite microstructure with a fine grain size for the α-Fe phase in the alloy.
LIU Jian-huaZHANG Peng-yueZHANG Jing-wuLI HuiZHANG Xiang-yi
