Research On Crystallization Technology Of Fe-based Amorphous Alloys

The Fe-based amorphous soft-magnetic alloy is the end of 1980's to discovers of high degree that a new and second steady soft-magnetic material, it can cause people with the cheap cost with the excellent magnetisming to pay attention to. A kind of material has been recognized as the best soft-magnetic material of combination property by the world at the present time, because it has perfect magnetics, such as μc, Bs, Hc. This kind of material is already extensive now to be used for common mode choke of high frequency circuit changer, high frequency dc-to-ac converter, zero order mutual-inductor and etc. At the same time this kind of material is also the best material for high fidelity magnetic head, high performance magnetic amplifier. The kind of alloy has the very big internal stress by the method of urgent cooling. So it must be treated by certain the heat treating craft as to improve its stability and high frequency magnetism performance. But different craft can cause different crystal mode, and crystal grains often grow up, plastic nature of material reduce, brittleness increase. This article studied the influence of different heating temperature, different rate of heating, different time of heat preservation, relaxation annealing and element to the process of alloy crystallization by XRD, DSC and SEM.The experiment results show that thermodynamics parameter of alloy cause distinct change by using different substitute element. The thermal parameters of amorphous alloy Fe₇₄Al₄Ga₂P₁₂B₄Si₄, Fe₇₃Nb₁Al₄Ga₂P₁₂B₄Si₄ and Fe₇₃Ni₁Al₄Ga₂P₁₂B₄Si₄ are 31.6K, 28.9Kand 26.9K. The thermal parameters of amorphous alloy disappeared by using Cu substituting for Fe. The reason may be the thermal parameters overlaped. And with different element, the crystallized structure of the alloy are widely different. The crystallization of original sample looks like chrysanthemum, and the grain size becomes bigger, and the crystallization time becomes shorter. The grain size distinctly reduces after Cu substituting for Fe, and the Cu compound presents meshwork shape and the time of crystallization becomes longer. The grain presented needle shape, with Ni substituting for Fe, grain becomes smaller and the time of crystallization becomes shorter. The grain presents mushroom shape, with Nb substituting for Fe, grain becomes smaller and the time of crystallization becomes shorter. The crystallization can scan by using SEM. The process of crystallization of the alloy...