Figure 18.30 shows the B-versus-H curve for a steel alloy.(a) What is the saturation flux...

Material

Composition (wt%)

Initial Relative Permeability µi

Saturation Flux Density Bs [tesla (gauss)]

Hysteresis Loss/Cycle J/m3 (erg/cm3)]

Resistivity ρ (Ω m)

Commercial iron ingot

99.95 Fe

150

2.14 (21,400)

270 (2,700)

1.0 × 10–7

Silicon–iron (oriented)

97 Fe, 3 Si

1,400

2.01 (20,100)

40 (400)

4.7 × 10–7

45 Permalloy

55 Fe, 45 Ni

2,500

1.60 (16,000)

120 (1,200)

4.5 × 10–7

Supermalloy

79 Ni, 15 Fe, 5 Mo, 0.5 Mn

75,000

0.80 (8,000)

—

6.0 × 10–7

Ferroxcube A

48 MnFe2O4, 52 ZnFe2O4

1,400

0.33 (3,300)

~40 (~400)

2,000

Ferroxcube B

36 NiFe2O4, 64 ZnFe2O4

650

0.36 (3,600)

~35 (~350)

107

Material

Composition (wt%)

Remanence Br [tesla (gauss)]

Coercivity Hc [amp-turn/m (Oe)]

(BH)max[kJ/m3 (MGOe)]

Curie Temperature Tc [°C(°F)]

Resistivity ρ (Ω m)

Tungsten steel

92.8 Fe, 6 W,

0.5 Cr, 0.7 C

0.95

9,500)

5,900

(74)

2.6

(0.33)

760

(1,400)

3.0 × 10−7

Cunife

20 Fe, 20 Ni,

60 Cu

0.54

(5,400)

44,000

(550)

12

(1.5)

410

(770)

1.8 × 10−7

Sintered alnico 8

34 Fe,7 Al,

15 Ni, 35 Co,

4 Cu, 5 Ti

0.76

(7,600)

125,000

(1,550)

36

(4.5)

860

(1,580)

—

Sintered ferrite 3

BaO–6Fe2O3

0.32

(3,200)

240,000

(3,000)

20

(2.5)

450

(840)

~104

Cobalt rare earth 1

BaO–6Fe2O3

0.92

(9,200)

720,000

(9,000)

170

(21)

725

(1,340)

5.0 × 10−7

Sintered neodymium– iron–boron

Nd2Fe14B

1.16

(11,600)

848,000

(10,600)

255

(32)

310

(590)

1.6 × 10−6