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1J77 (Soft magnetic alloy)
1J77 is a nickel-iron magnetic alloy, with about 80% nickel and 20%
iron content. Invented in 1914 by physicist Gustav Elmen at Bell
Telephone Laboratories, it is notable for its very high magnetic
permeability, which makes it useful as a magnetic core material in
electrical and electronic equipment, and also in magnetic shielding
to block magnetic fields. Commercial permalloy alloys typically
have relative permeability of around 100,000, compared to several
thousand for ordinary steel.
In addition to high permeability, its other magnetic properties are
low coercivity, near zero magnetostriction, and significant
anisotropic magnetoresistance. The low magnetostriction is critical
for industrial applications, allowing it to be used in thin films
where variable stresses would otherwise cause a ruinously large
variation in magnetic properties. Permalloy's electrical
resistivity can vary as much as 5% depending on the strength and
the direction of an applied magnetic field. Permalloys typically
have the face centered cubic crystal structure with a lattice
constant of approximately 0.355 nm in the vicinity of a nickel
concentration of 80%. A disadvantage of permalloy is that it is not
very ductile or workable, so applications requiring elaborate
shapes, such as magnetic shields, are made of other high
permeability alloys such as mu metal. Permalloy is used in
transformer laminations and magnetic recording heads.
1J77 widely used in radio-electronic industry, precision
instruments, remote control and automatic control system.
Normal composition%
Ni | 75.5~78 | Fe | Bal. | Mn | 0.3~0.6 | Si | 0.15~0.3 |
Mo | 3.9~4.5 | Cu | 4.8~6.0 | ||||
C | ≤0.03 | P | ≤0.02 | S | ≤0.02 |
Typical Mechanical properties
Yield strength | Tensile Strength | Elongation |
Mpa | Mpa | % |
980 | 980 | 2~40 |
Typical Physical properties
Density (g/cm3) | 8.6 |
Electrical resistivity at 20ºC(Om*mm2/m) | 0.55 |
Coefficient of linear expansion(20ºC~200ºC)X10-6/ºC | 10.3~11.5 |
Saturation magnetostriction coefficient λθ/ 10-6 | 2.4 |
Curie point Tc/ ºC | 350 |
The magnetic properties of alloys with high permeability in weak fields | |||||||
1J77 | Initial permeability | Maximum permeability | Coercivity | Saturation magnetic induction intensity | |||
Сold-rolled strip/ sheet. Thickness, mm | μ0.08/ (mH/m) | μm/ (mH/m) | Hc/ (A/m) | BS/ T | |||
≥ | ≤ | ||||||
0.01 mm | 17.5 | 87.5 | 5.6 | 0.75 | |||
0.1~0.19 mm | 25.0 | 162.5 | 2.4 | ||||
0.2~0.34 mm | 28.0 | 225.0 | 1.6 | ||||
0.35~1.0 mm | 30.0 | 250.0 | 1.6 | ||||
1.1~2.5 mm | 27.5 | 225.0 | 1.6 | ||||
2.6~3.0 mm | 26.3 | 187.5 | 2.0 | ||||
cold drawn wire | |||||||
0.1 mm | 6.3 | 50 | 6.4 | ||||
Bar | |||||||
8-100 mm | 25 | 100 | 3.2 |
Mode of heat treatment 1J77 | |
Annealing media | Vacuum with a residual pressure not higher than 0.1Pa, hydrogen with a dew point of not higher than minus 40 ºC. |
The heating temperature and rate | 1100~1150ºC |
Holding time | 3~6 |
Cooling rate | With 100 ~ 200 ºC/ h cooled to 600 ºC, rapidly cooled to 300ºC |
Style of supply
Alloys Name | Type | Dimension | ||
1J77 | Wire | D= 0.1~8mm | ||
1J77 | Strip | W= 8~390mm | T= 0.3mm | |
1J77 | Foil | W= 10~100mm | T= 0.01~0.1 | |
1J77 | Bar | Dia= 8~100mm | L= 50~1000 |
FAQ
1. What's the minimum quantity customer can order?
If we have your size in stock, we can provide any quantity you
want.
If we do not have, for spool wire, we can produce 1 spool, about
2-3kg. For coil wire, 25kg.
2. How can you pay for small sample amount?
We have Western union account, wire transfer for sample amount also
ok.
3. Customer do not have express account. How will us arrange the
delivery for sample order?
Just need to provide your address information, we will check the
express cost, you can arrange the express cost together with sample
value.
4. What's our payment terms?
We can accept LC T/T payment terms, it also depending on delivery
and total amount. Let's talk more in details after getting your
detailed requirements.
5. Do you provide free samples?
If you want several meters and we have stock of your size, we can
provide, customer need to bear the International express cost.
6. What's our working time?
We will give you reply through email/phone Online contact tool
within 24 hours. No matter working day or holidays.