Toroidal Core


NiFe (Nickel Iron) alloys Magnetic & Chemical Properties:

Magnetic & Chemical Properties
Properties Measurement Unit 80% NiFe7 Mumetal7
Permeability Permeability AC
Bs Tesla 0.751 0.761
Br Tesla 0.42 0.52
Hc 2(A.m)-1 Tesla 0.35 0.6
µ4 4 Tesla 550000 120000
µ max Tesla 570000 350000
Permeability AC
µ4z5 70000 50000
µz86 - -
µmax 95000 95000
Core loss (W/Kg-1) 0.015 0.015
Chemical Composition % Ni - 78%-81% 78%-81%
% Mo - 4.5%-6% 4.5%-6%
% Si - 0.05%-0.4% 0.05%-0.4%
% Mn - 0%-0.5% 0%-0.5%
% C - 0.01% 0.01%
% Fe - Balance Balance
Physical
Properties
Density (g.cm -3) 8.7 8.7
Specific Heat (J.Kg-1.˚C-1) 460 460
Thermal conductivity W.m-1.˚C-1 19 19
Mean CTE between -50 & +200˚C ˚C-1 12.10-6 12.10-6
Electrical resistivity µΩ.cm 60 60
Curie Point ᵒC 420 420
Coefficient of magnetostriction at Saturation ∆l / l - 1-3 x 10-6 1-3 x 10-6
Melting temperature ᵒC 1450 1450
Saturation Induction Tesla - -
Hardness Hv 325 325
In Cold worked
condition
UTS MPa 1050 1050
0.2% PS(Cold Worked) MPa 1030 1030
Elongation % min 3 min 3
In Annealed
condition
Hardness Hv 160 160
UTS MPa 650 650
0.2% PS MPa 280 280
Elongation % 35 35
Grain Size - 8 8

Key:

  1. Practical saturation measured for H = 800 A/m.
  2. Remanent induction Br and coercive field Hc measured from H = 80 A/m.
  3. Practical saturation Bs and Remanent induction Br measured for H = 800 A/m.
  4. Measured for H = 4 mA/cm (peak value).
  5. Sinusoidal excitation field H = 4 mA/cm (peak value).
  6. Impedance permeability for B = 0.8 T.
  7. Measurements made on 35X26X0.34 mm ring specimens after annealing in Pure
    & Dry Hydrogen for 4h at 1170°C followed by cooling at 200°C/h.
  8. Practical saturation measured for H=5000A/m.
  9. Core loss W/kg at 1.5T at 50Hz=3.90 max.
  10. Typical operating frequency - 50 hz to 400hz

Dimensions and tolerances:

Nominal Value (mm) Tolerance for inner
diameter(mm)
Tolerance for outer
diameter(mm)
≤60 +/-0.5 +/-1
≤80 +/-0.75 +/-1.25
≤100 +/-1 +/-1.5
≤200 +/-1.5 +/-2
≤320 +/-2 +/-2.5

Non - roundness is considered in the diameter tolerances

Sample Core-

  • Geometry
  • Outer Diameter - 160 mm+/-2mm
  • Inner Diameter - 110 mm+/-1mm
  • Height - 30 mm+0.2 /- 0.0 mm

Ind Pk(T) Permeability Loss/kg (Wt) H EffPk (A/cm) H RMS (A/cm) Ind RMS (T) Hc (A/cm) Br (T)
0.1 127150.24 0 0.0083 0.0059 0.0672 0.0019 0.02
0.2 144038.48 0 0.0134 0.0095 0.1378 0.0073 0.0868
0.3 158385.11 0 0.0188 0.0133 0.2102 0.0125 0.1708
0.4 164657.89 0 0.0242 0.0171 0.277 0.0166 0.2839
0.5 115868.36 0.0061 0.1674 0.1183 0.352 0.0204 0.3449
0.6 41492.51 0.015 0.3746 0.2649 0.4307 0.024 0.3815
0.636 14717.2 0.0183 0.4492 0.3176 0.4591 0.0253 0.3947