Magnet core

Abstract

A magnet core has a linear B-H loop, a high modulability with alternating current and direct current, a relative permeability of more than 500 but less than 15,000, and a saturation magnetostriction lambdas of less than 15 ppm, and is made of a ferromagnetic alloy, at least 50 percent of which consist of fine crystalline parts having an average particle size of 100 nm or less (nanocrystalline alloy) and which is characterized by formula FeaCobNicCudMeSifBgXh, wherein M represents at least one of the elements V, Nb, Ta, Ti, Mo, W, Zr, Cr, Mn, and Hf, a, b, c, d, e, f, g are indicated in atomic percent, X represents the elements P, Ge, C and commercially available impurities, and a, b, c, d, e, f, g, h satisfy the following conditions: 0<=b<=40; 2<c<20; 0.5<=d<=2; 1<=e<=6; 6.5<=f<=18; 5<=g<=14; h<5 atomic percent; 5<=b+c<=45, and a+b+c+d+e+f=100.

What is claimed is: 
     
         1 . A magnet core with a linear B-H loop and a high modulability in alternating current and direct current,
 comprising a relative permeability μ that is greater than 500 and less than 15,000, a saturation magnetostriction λ s  whose amount is less than 15 ppm and consisting of a ferromagnetic alloy in which at least 50% of the alloy consists of fine crystalline particles with an average particle size of 100 nm or less and is characterized by the formula Fe a Co b Ni c Cu d M e Si f B g X h  in which M is at least one of the elements from the group consisting of V, Nb, Ta, Ti, Mo, W, Zr, Cr, Mn and Hf,   a, b, c, d, e, f, g are stated in atom %,   X denotes elements P, Ge, C as well as commercial dopants and a, b, c, d, e, f, g, h satisfy the following conditions:   0≤b≤40;   2<c<20;   0.5≤d≤2;   1≤e≤6;   6.5≤f≤18;   5≤g≤14;   h<5 atom %   with 5≤b+c≤45, in which a+b+c+d+e+f=100.   
     
     
         2 . A magnet core according to  claim 1 , wherein
 a, b, c, d, e, f, g, h satisfy the following conditions:   0≤b≤20;   2<c<15;   0.5≤d≤2;   1≤e≤6;   6.5≤f≤18;   5≤g≤14;   h<5 atom %   with 5≤b+c≤30, in which a+b+c+d+e+f=100.   
     
     
         3 . A magnet core according to  claim 1 , wherein
 a, b, c, d, e, f, g, h satisfy the following conditions:   0≤b≤10;   2<c<15;   0.5≤d≤2;   1≤e≤6;   6.5≤f≤18;   5≤g≤14;   h<5 atom %   with 5≤b+c≤20, in which a+b+c+d+e+f=100.   
     
     
         4 . A magnet core according to  claim 1 , wherein
 a, b, c, d, e, f, g, h satisfy the following conditions:   0.7≤d≤1.5;   2≤e≤4;   8≤f≤16;   6≤g≤12; with   h<2.   
     
     
         5 . A magnet core according to  claim 1 , wherein a Co content is less than or equal to a Ni content. 
     
     
         6 . A magnet core according to  claim 1 , wherein the magnet core is in the form of an annular band core wound from a band with a thickness of less than 50 μm. 
     
     
         7 . A magnet core according to  claim 1 , wherein the amount of a coercitivity field intensity H c  is less than 1 A/cm. 
     
     
         8 . A magnet core according to  claim 1 , wherein a remanence ratio is less than 0.1. 
     
     
         9 . A magnet core according to  claim 1  having a relative permeability μ greater than 1000 and less than 10,000. 
     
     
         10 . A magnet core according to  claim 1  having a relative permeability μ greater than 1500 and less than 6000. 
     
     
         11 . A magnet core according to  claim 1 , wherein a saturation magnetostriction λ s  is less than 10 ppm. 
     
     
         12 . A magnet core according to  claim 1 , wherein at least 50% of the alloy is accompanied by fine crystalline particles with an average particle size of 50 nm or less. 
     
     
         13 . A magnet core according to  claim 1 , wherein the magnet core is configured as a closed toroidal core, oval core or rectangular core without air gap. 
     
     
         14 . A magnet core according to  claim 1 , wherein the magnet core is fixed in a trough. 
     
     
         15 . A magnet core according to  claim 14 , wherein for fixation of the core a soft elastic reaction adhesive and/or a soft plastic nonreactive paste is provided. 
     
     
         16 . A method for production of a magnet core comprising a relative permeability μ that is greater than 500 and less than 15,000, a saturation magnetostriction λ s  whose amount is less than 15 ppm and consisting of a ferromagnetic alloy in which at least 50% of the alloy consists of fine crystalline particles with an average particle size of 100 nm or less and is characterized by the formula Fe a Co b Ni c Cu d M e Si f B g X h  in which M is at least one of the elements from the group consisting of V, Nb, Ta, Ti, Mo, W, Zr, Cr, Mn and Hf,
 a, b, c, d, e, f, g are stated in atom %, 
 X denotes the elements P, Ge, C as well as commercial dopants and a, b, c, d, e, f, g, h satisfy the following conditions: 
 0≤b≤40; 
 2<c<20; 
 0.5≤d≤2; 
 1≤e≤6; 
 6.5≤f≤18; 
 5≤g≤14; 
 h<5 atom % 
 with 5≤b+c≤45, in which a+b+c+d+e+f=100, the method comprising the step of performing a heat treatment in a magnetic transverse field of the magnet core. 
 
     
     
         17 . A method according to  claim 16 , wherein a heat treatment is also performed in a magnetic longitudinal field. 
     
     
         18 . A method according to  claim 16 , wherein a heat treatment is performed in the transverse field before a heat treatment in a longitudinal field. 
     
     
         19 . A method according to  claim 16 , wherein a heat treatment is performed in the transverse field after heat treatment in a longitudinal field. 
     
     
         20 . A current transformer for alternating power with a magnet core comprising a relative permeability μ that is greater than 500 and less than 15,000, a saturation magnetostriction λ s  whose amount is less than 15 ppm and consisting of a ferromagnetic alloy in which at least 50% of the alloy consists of fine crystalline particles with an average particle size of 100 nm or less and is characterized by the formula Fe a Co b Ni c Cu d M e Si f B g X h  in which M is at least one of the elements from the group consisting of V, Nb, Ta, Ti, Mo, W, Zr, Cr, Mn and Hf,
 a, b, c, d, e, f, g are stated in atom %, 
 X denotes the elements P, Ge, C as well as commercial dopants and a, b, c, d, e, f, g, h satisfy the following conditions: 
 0≤b≤40; 
 2<c<20; 
 0.5≤d≤2; 
 1≤e≤6; 
 6.5≤f≤18; 
 5≤g≤14; 
 h<5 atom % 
 with 5≤b+c≤45, in which a+b+c+d+e+f=100, 
 wherein the current transformer, in addition to the magnetic core as transformer core, has a primary winding and at least one secondary winding, wherein the secondary winding is low-resistance terminated by a load resistance and/or measurement electronics. 
 
     
     
         21 . A current transformer according to  claim 20  having a phase error of a maximum 7.5° C. in a circuit with a load resistance and/or measurement electronics according to a respective specification and dimension. 
     
     
         22 . A current transformer according to  claim 21  having a phase error of a maximum 5° C. in a circuit with a load resistance and/or measurement electronics according to a respective specification and dimension. 
     
     
         23 . A current-compensated inductor with a magnet core according to  claim 1 , wherein the inductor has at least two windings in addition to the magnet core. 
     
     
         24 . A current-compensated inductor according to  claim 23 , wherein the inductor has an insertion attenuation of at least 20 dB in the frequency range from 150 kHz to 1 MHz even during flow of a discharge current of at least 10% of the nominal current. 
     
     
         25 . A current-compensated inductor according to  claim 24 , wherein the inductor has an insertion attenuation of at lest 20 dB in the frequency range from 150 kHz to 1 MHz even during flow of a discharge current of at least 20% of the nominal current.