Review of Passive Electromagnetic Devices for Vibration Damping and Isolation

Table 1

Magnetic properties of different engineering materials.

Material type	Coercivity, bHc (kA/m)	Remanence, Br (T)	Relative permeability	Saturation, bsat (T)
Ferrite magnet	150–250	0.35–0.4	1.2–1.9	0.35–0.4
Alnico magnet	30–151	0.7–1.11	1.2–1.9	0.7–1.2
Neodymium-iron magnet	675–1090	0.87–1.5	1.05	0.87–1.5
Samarium-cobalt magnet	493–790	0.83–1.15	1.05	3000
Iron	0.006–0.080	0.01–0.06	150–2000	1.6–2.15
Nickel	0.056–2.01	0.01–0.15	100–600	0.4–0.6
Cobalt	0.80–71.62	0.02–0.2	70–250	0.7–0.9
Co-Fe alloy (49% Co)	0.07–0.09	0.1–0.3	8000–15000	2.2–2.4
Ni-Fe alloy (75% Ni)	0.001–0.002	0.05–0.2	60000–250000	0.6–0.8
Ni-Fe alloy (50% Ni)	0.005–0.010	0.03–0.15	7000–100000	1.5
Electrical steel	0.032–0.072	0.5–0.8	3000–4000	1.6–2
Stainless steel 304/316	1–3	0.001–0.002	1.003–1.012	0.025–0.03
Stainless steel 430	0.5	0.8	750	1.4
Copper OFCH	—	—	0.99	—
Aluminium 7075	—	—	1.004	—
Titanium grade 5	—	—	1.0001	—
PTFE Teflon	—	—	1	—
Polyimide	—	—	1	—
Nylon	—	—	1	—