Preparation Of Amorphous And Nanocrystalline Soft Magnetic Material And Its Properties

An experimental melt spinning equipment with the copper roller 450mm in diameter, 150mm in width and ±15μm in radial vibration, which has circulating cooling and good airproof and 35.37m/s in the max wheel speed has been fabricated. In the process of designning, processing and installing, the precision of this equipment has been improved. The amorphous ribbons have been prepared with rapid solidification technology in experimental condition. Also it will be used to industrialization. The properties of Fe78Si9B13 , Fe73.5Cu1Nb3Si13.5B9, Fe74Cu1Mo2Nb1Si13B9, Co66Fe4NiB14S15 and Fe16Ni60Cr4B16Si4 alloys have been investigated mostly by means of differential thermal analysis(DTA),X-ray diffraction meter(XRD), Vabrating sample magnetometer(VSM), scanning electron microscope(SEM) et al. techniques. The optimal comprehensive properties have been obstained by the proper heat treatment process.It would be found that amorphous alloys would be crystallization at different degree with the temperature increase of heat treatment. The two phases structure of amorphous and nanocrystalline could be obstained by Fe-based amorphous alloys of some elements within best temperature rage. The average grain size was in the range of 8~16nm. Especially, Amorphous soft magnetic alloys which were thermodynamical metastable state would take place atom recognition in the process of annealed treatment resulted in the brittleness. The excellent coopertation of tenacity and magnetism was achieved by adjusting the heat treatment technologies. In this paper, the optimal comprehensive properties of alloys could be obstained by FeygSi9B13, Fe73.5Cu1Nb3Si13.5B9, Fe74Cu1Mo2Nb1Si13B9 alloys after 1h anneald at 753K, 813K, 773K respectively. At the same time, the addition of Cu, Nb, Mo elements could be benefit to improve crystallization temperature and stabilize amorphous structure. The addition of Cu atoms had significant effect on the nucleation process of a Fe-Si phase. The Nb atoms would preferently intetact with the B atoms and form relatively stable clustetrs. Thus, the clusters might influence on the thermal stabilities, the precipitation of the Fe2B, and the growth of the a Fe-Si nanocrystallities.Comparing with the crystallization of above alloys indicated that the soft magnetic properties of Fe735Cu1Nb3Si135B9 alloy was as well as Co66Fe4NiB14Si15 alloy after 1h annealed at 833K. Yet the average grain size of Co66Fe4NiB14Si15 alloy was larger, its resistance to corrosion was less than Fe73.5Cu1Nb3Si13.5B9 alloy. The average grain size of Fe16Ni6oCr4B16Si4 alloy accessed to lμm after Ih annealed at 773K, And its soft magnetic properties was between Co66Fe4NiB14Si15 alloy and Fe78Si9B13 alloy. The crystalline phases of Fe735Cu1Nb3Si13.5B9 alloys was stabilized, The Fe735Cu1Nb3Si135B9 alloy with 8-11nm crystalline grain was good thermal stability and time stability, Thus this kind of alloy would be an extensive application.