The Relationship Between Initial Permeability And Temperature Of Fe-based And Co-based Nanocrystal Alloys

The relationship between initial permeability and temperature has been studied in this paper. In this way, we can get the role of magnetic exchange coupling in the nanocrystalline soft magnetic alloy magnetic properties.The detection means have been used such as DTA,DSC,XRD,Hopkinson to study the influence of annealing temperature onμi-T curves of soft magnetic materials series, including Co69-xFexNb6Si15B10 (x=10,14,18), Co75-xFexNb5Sii2B8 (x=11,15), Fe73.5Cu1Nb3Si15.5B7, and Fe73.5Cu1Nb3Si13.5B9. The influence of magnetic intensity onμi-T curves of soft magnetic materials series, including Fe73.5Cu1Nb3Si15.5B7 and Fe73.5Cu1Nb3Si13.5B9 has been studied also. So we can draw these conclusions as follows.Twice crystallization processes have been found in the experience process of the series of Co69-xFexNb6Si15B10 (x=10,14,18) and Fe73.5Cu1Nb3Si13.5B9 alloy. At the same time, three times crystallization processes have been found in the experience process of Fe73.5Cu1Nb3Si155B7 alloy. The sharp Hopkinson peak appeared in theμi-T curves when they were in quenched. The characteristics of Hopkinson peak, smooth peak, macrurous character and arise have been sequence presented on theμi-T curves of Co69-xFexNb6Si15Bio (x=10,14, 18) series, Co75-xFexNb5Si12B8 (x=11,15), Fe73.5Cu1Nb3Si15.5B7 alloy and Fe73.5Cu1Nb3Si13.5B9 alloy with the arising of the annealing temperature, but not all alloys had all of these characteristics.There were 3 steps during the crystallization process of nanocrystalline alloys:I [Am]→Ⅱ[Am+nano-crystal grain]→>Ⅲ[Am+ nano-crystal grain+compound].Theμi-T curves of Fe73.5Cu1Nb3Si15.5B7 and Fe73.5Cu1Nb3Si13.5B9 alloy were related with the magnetic intensity. The Hopkinsonoid peak always appeared in weak magnetic intensity, and then appeared the smooth peak while the magnetic intensity achieving some degrees of Fe73.5Cu1Nb3Si15.5B7 alloy that annealed from 390℃to 480℃and Fe73.5Cu1Nb3Si13.5B9 alloy from 420℃to 550℃. The reasons of this phenomenon appeared as follows. Magnetic exchange coupling was implemented depending on non-crystalline base, and the magnetic intensity can change the magnetic characteristic of non-crystalline base.