Research On Dynamic Behavior And Magnetic Properties Of Fe₉₀Zr₇B₃ Metallic Glass In Air

Fe-base amorphous alloy have got people's attention and been considered for use in many commercial components because of their excellent soft magical property, excellent strength, stiffness and better physical/chemical properties, as compared to traditional crystalline alloys.Fe-base amorphous alloy are of particular applications, such as micro-electronic cores and soft magnet tubes. In order to use Fe-base amorphous alloy for different temperature applications, a profound understanding of the oxidation behavior is essential. Fe₉₀Zr₇B₃ amorphous alloy have been used in industry for their excellent magnetic properties, it's necessary to understand the oxidation behavior at high temperature in different atmosphere. Some papers have already mentioned the oxidation of Fe-base amorphous alloy. We conducted a band of minor surface oxidation to simulate and discuss the actual use of the process of change brought about by oxidation.This article mainly introduced five aspects work. First of all, Fe₉₀Zr₇B₃ amorphous alloy was prepared by single-rolling method and its structure, glass-forming ability and thermal stability were also studied by use of X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry analyzer (TG). It showed the alloy was amorphous and the crystallization of the alloy was 512.8℃. Secondly, non-isothermal oxidation studies of Fe₉₀Zr₇B₃ amorphous alloy were carried out in air at different heating rates and its relative oxidation behavior was studied. The onset temperature of the alloy was 637.8℃and the alloy was very stable under 480℃. The activation energy of the Fe₉₀Zr₇B₃ amorphous ribbons was calculated by Kissinger plot. And the activation energy value of the alloy was 483 kJ/mol. Thirdly,the weight gains began at 600℃and finished at 1100℃. The tg curves of the alloy in air showed the oxidation of the alloy had three stages. And it may be related to the components of the alloy. It also showed the oxidation fracture of the alloy in the total oxidation stage. Fourthly, the structures of the alloy heat treatment for short time at different temperture were studied by X-ray diffraction. The TGA curves's difference between the the original sample and the sample heat treatment after a short-term oxidation were discussed. At last, the magnetic properties of the alloy were measured after heat treatment at different temperature for different times. Also, the heat treatment temperature was near or below the glass-forming temperature. The results showed the magnetic properties changed little at lower temperature and it related to the amorphous state of the alloy. The hysteresis loops of Fe₉₀Zr₇B₃ amorphous alloy heat treatment at 450℃for 15 min has changed. The changes of the alloy's magnetic properties with the oxidation temperature and oxidation time were discussed. The values of saturation magnetization were improved by oxidation, but the values of residual magnetization and coercivity of the alloy were enlarged at the same time.