Characteristics

Composition

Sm2Co17

SmCo5

NdFeB

Physical characteristics

Curie temperature

℃

800 to 850

700 to 750

310 to 350

(K)

(1073 to 1123)

(973 to 1023)

583 to 623

Thermal expansion coefficient

C//

1℃

6×10-6

6×10-6

（3-4）×10-6

(1K)

(6×10-6)

(6×10-6)

（3-4）×10-6

C⊥

1℃

13×10-6

13×10-6

（1-3）×10-6

(1K)

(13×10-6)

(13×10-6)

（1-3）×10-6

Thermal conductivity

Kcal/mhr℃

10

11

6.6-8.3

(W/mK)

(12)

(13)

8-10

Specific heat

Cal/g℃

8×10-2

9×10-2

1.2×10-1

(J/kgK)

(335)

(377)

(504)

Specific resistivity

Ω-cm

8.6×10-5

5.3×10-5

（1.4-1.6）×10-4

Mechanical characteristics

Deflection strength

Kg/mm2

15

18

25

(N/m2)

(1.5×108)

(1.8×108)

(2.5×108)

Compressive trength

Kg/mm2

82

102

100-110

(N/m2)

(8×108)

(10×108)

（1-1.1）×109

Tensile strength

Kg/mm2

3.6

4.1

8-9

(N/m2)

(3.5×107)

(4×107)

（8-9）×107

Young’s modulus

Kg/mm2

1.2×104

1.6×104

（1.5-2）×104

(N/m2)

(1.2×1011)

(1.6×1011)

（1.5-2）×1011

Vickers hardness

Hv

500 to 600

450 to 500

500 to 600