NiFe (Nickel Iron) Soft Magnetic Alloys and Their Properties

Magnetic & Chemical Properties:

Magnetic & Chemical Properties
No. Properties Measurement Unit 80% NiFe7 Mumetal7 48% NiFe8 Si Steel
1 DC Magnetic Properties Bs Tesla 0.751 0.761 1.53 1.7310
Br Tesla 0.42 0.52 1.13 -
B at 100 A/m Tesla - - 1.2 -
Hc 2 A/m 0.35 0.6 2.8 -
µ4 4 - 550000 120000 - -
µ max - 570000 350000 190000 -
2 60Hz AC Magnetic Properties µ4z5 - 70000 50000 10400 >2500
µz86 - - - 54000 -
µ max - 95000 95000 - -
Core loss W/Kg 0.015 0.015 0.4 3.911
3 Chemical Composition Ni % 78-81 78-81 47-48 Nil
Mo % 4.5-6 4.5-6 Nil Nil
Si % 0.05-0.4 0.05-0.4 0.1 1.6 - 2.1
Mn % 0-0.5 0-0.5 0.50 0.5
C % 0.01 0.01 0.005 0.01
Fe % Balance Balance Balance Balance

Physical Properties:

Physical Properties
No. Properties Measurement Unit 80% NiFe7 Mumetal7 48% NiFe8 Si Steel
4 Physical Properties Density g.cm² 8.7 8.7 8.2 7.75
specific Heat J.Kg-1.˚C-1 460 460 500 -
Thermal conductivity W.m-1.˚C-1 19 19 13 -
Mean CTE between -50 & +200˚C ˚C-1 12.10-6 12.10-6 8 -
Electrical resistivity µΩ.cm 60 60 45 -
Curie Point ᵒC 420 420 450 -
Coefficient of magnetostriction at Saturation ∆l / l - 1-3 x 10-6 1-3 x 10-6 24 x 10-6 -
Melting temperature ᵒC 1450 1450 1425 -
Saturation Induction Tesla - - 1.6 -
Hardness(Cold Worked) Hv 325 325 250 155
UTS(Cold Worked) MPa 1050 1050 850 380
0.2% PS(Cold Worked) MPa 1030 1030 820 250
Elongation(Cold Worked) % 3 3 3 min 30
Hardness(Annealed) Hv 160 160 140 -
UTS(Annealed) MPa 650 650 500 -
0.2% PS(Annealed) MPa 280 280 250 -
Elongation(Annealed) % 35 35 40 -
Grain Size(Annealed) - 8 8 9 -
Hardness(Finished Part) Hv 110 110 100 -
UTS(Finished Part) MPa 530 530 450 -
0.2% PS(Finished Part) MPa 160 160 200 -
Elongation(Finished Part) % 45 45 40 -
Grain Size(Finished Part) - 0-3 0-3 0 -

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. Measurements made on 36X25X0.34 mm ring specimens after annealing in Pure
    & Dry Hydrogen for 4h at 1150°C.
  9. Measurements made on 36x25x0.34 mm ring specimens after annealing in pure
    & dry Hydrogen for 2h at 1150 ºC.
  10. Practical saturation measured for H=5000A/m.
  11. Core loss W/kg at 1.5T at 50Hz=3.90 max.