The Preparation And Soft Magnetic Properties Of FeCoNiSiB Amorphous Alloys

In this dissertation, alloy ingots were prepared by vacuum consumable type electric arc furnace under a high purity Argon atmosphere. FeCoNiSiB-based amorphous alloy ribbons were prepared by single roller melt-spinning method,crystal structures and soft magnetic properties of alloy ribbons had been investigated and measured by x-ray diffraction (XRD), differential scanning calorimeter (DSC), Vibrating sample magnetometer (VSM) and Soft magnetic dc analyzer. Effects of Si, Ni and B alloying additions on the structure and properties of FeCoNiSiB alloys by micro alloying technology were studied. This article is specified in the following aspects:1) The effect of of Si alloying additions in the Fe4oNi38Mo4B(18.x)Six on the structure and properties of as-quenched and annealed alloys was studied. The results showed that as the Si element content added, the coercivity(Hc) showed a decreasing trend firstly and increased again, Fe4oNi38Mo4B14Si4 amorphous has a lower Hc of 5.8 A/m.2) It was found that Fe4oNi38Mo4B14Si4 ribbon has the highest Ms about 112.6 emu/g at annealed at 405 ℃ for 10 min and the lowest Hc about 7.0A/m at annealed at 345 ℃ for lOmin.3) The effect of of B alloying additions in the (Feo.39Co0.15Ni0.46)94-yBySi6 on the structure and properties of as-quenched alloys was studied. The results showed that the initial temperatures of primary crystallization of as-quenched alloys ribbons were improved with increase of B atom content, but the range between initial temperatures of primary and secondary crystallization of the amorphous ribbons decrease. (Feo.39Co0.15Ni0.46)80B14Si6 amorphous alloy has the highest Ms of 94.6 emu/g and (Feo.39Coo.15Ni0.46)82B12Si6 amorphous alloy has the lowest Hc of l0.lA/m.4) It was found that (Feo.39Coo.15Ni0.46)8oB14Si6 ribbon has the highest Ms about 99.2 emu/g at annealed at 465℃ for l0min and the lowest Hc about 5.9 A/m at annealed at 425℃ for 10 min.5) The effect of of Si alloying additions in the (Feo.39Coo.5Ni0.11)8oB2o-zSiz on the structure and properties of as-quenched alloys was studied. The results showed that as the Si element content added, the initial temperatures of primary and secondary crystallization of as-quenched alloys ribbons showed a increasing trend firstly and decreased again. It was found that (Fe0.39Co0.5Nio.11)80B12Si8 amorphous alloy has the highest Ms of 147.7 emu/g and (Feo.39Coo.5Ni0.11)8oB18Si2 amorphous alloy has the lowest Hc of 12.2A/m.6) It was found that (Fe0.39Co0.5Ni0.11)80B12Si8 ribbon has the highest Ms about 132.8 emu/g at annealed at 370 ℃ for l0min and the lowest Hc about 12.4 A/m at annealed at 430℃ for lOmin.