1J85 Permalloy (81Ni-Fe High Permeability Soft Magnetic Alloy) - Supplier of Strip, Bar & Wire | Shanghai Hangbo Alloy Group
Date: 2026年7月28日 Categories: News Views: 347
By Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier | ISO 9001:2015 Certified | Est. 2012
Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp (Lisa): +86 13611656360
Quick Answer: What Is 1J85?
1J85 (81Ni-Fe / 81 Permalloy) is a premium nickel-iron soft magnetic alloy with approximately 81% nickel and 5% molybdenum that achieves extreme magnetic permeability (typically >=300,000 mu-m) and ultra-low coercivity (<=1.6 A/m), making it ideal for magnetic shielding in aerospace sensors, high-fidelity audio transformers, and precision current transformer cores. Shanghai Hangbo Alloy Group supplies 1J85 in precision cold-rolled strip, round bar, and wire with certified GB/T 14985 magnetic properties.
Industry Pain Point: Instrument calibration labs often struggle with ambient magnetic noise (50/60 Hz power-line interference) corrupting micro-volt measurements. A single-layer 1J85 magnetic shield can provide 40-60 dB of low-frequency field attenuation -- 10x better than standard 1J50 steel shielding -- without the massive weight and cost of multi-layer Mu-metal rooms.
Key Properties at a Glance
| Property | Value |
|---|---|
| Grade | 1J85 (GB) / 81 Permalloy |
| Density | 8.75 g/cm3 |
| Curie Temperature | ~460C |
| Saturation Flux Density Bs | ~0.78 T |
| Max Permeability um | >=125 mH/m (standard); 300,000-500,000 typical |
| Initial Permeability ui | >=30 mH/m |
| Coercivity Hc | <=1.6 A/m (0.02 Oe) |
| Electrical Resistivity | ~0.56 micro-ohm-m |
| Key Standards | GB/T 14985, ASTM A753 Type 4 |
Product Overview
1J85 represents the evolution of the 79 Permalloy family: by increasing nickel content to ~81% and adding a precise 5% molybdenum content, it pushes the magnetocrystalline anisotropy (K1) and magnetostriction (lambda) simultaneously to near zero. This "magic intersection" in the Ni-Fe-Mo ternary system is where domain walls move freely under the weakest magnetic fields.
The resulting magnetic permeability is extreme. While 1J50 (50% Ni) is suitable for general shielding and 1J79 (79% Ni) suits high-sensitivity sensors, 1J85 is for "extreme sensitivity" -- the alloy of choice for detecting the Earth's magnetic field variations (geomagnetic sensing), for the input transformers of high-end moving-coil phono cartridges, and for shielding SQUID magnetometers.
Key distinguishing features of 1J85:
- Ultra-High Max Permeability: 1J85's mu-max can reach 500,000+ in optimally annealed labs, far surpassing 1J50 and slightly edging out 1J79.
- Ultra-Low Loss: The coercivity is extremely low (<=1.6 A/m), meaning the alloy loses very little energy when magnetically cycled, making it ideal for high-efficiency transformers.
- Mo Stabilization: The 5% molybdenum increases electrical resistivity to ~0.56 micro-ohm-m, reducing eddy current losses at AC frequencies compared to binary Ni-Fe alloys.
Shanghai Hangbo Alloy Group supplies 1J85 in the "as-rolled" (work-hardened) condition, allowing customers to stamp laminations before performing the critical final hydrogen anneal that unlocks the magnetic properties.
Executive Standards
| Product Form | Standard | Notes |
|---|---|---|
| Cold-Rolled Strip | GB/T 14985 | Thickness 0.02-2.5 mm; width to 400 mm |
| Cold-Drawn Wire | GB/T 14985 | Diameter 0.1-10 mm |
| Hot-Rolled Bar | GB/T 14985 | Diameter 10-200 mm |
| Plate | GB/T 32286.1 | Thickness 1.0-50 mm |
| International Equiv. | ASTM A753 Type 4 | 80Ni-5Mo-Fe |
Chemical Composition (wt.% per GB/T 14985)
| Element | Min | Max | Role |
|---|---|---|---|
| Nickel (Ni) | 80.5 | 81.5 | Minimizes magnetocrystalline anisotropy |
| Molybdenum (Mo) | 4.80 | 5.20 | Shifts zero-magnetostriction point; increases resistivity |
| Manganese (Mn) | 0.30 | 0.60 | Deoxidizer |
| Silicon (Si) | 0.15 | 0.30 | Deoxidizer |
| Carbon (C) | - | 0.030 | Must be ultra-low for clean grain boundaries |
| Iron (Fe) | Balance | - | Matrix |
Magnetic Properties (H2 Annealed, per GB/T 14985)
| Parameter | Standard (Min/Max) | Typical Optimal | Unit |
|---|---|---|---|
| Initial Permeability ui | >=30.0 | 50-90 | mH/m |
| Max Permeability um | >=125 | 300-500 | mH/m |
| Saturation Bs | ~0.78 | 0.75-0.82 | T |
| Coercivity Hc | <=1.6 | 0.8-1.2 | A/m |
Physical Properties
| Property | Value | Unit |
|---|---|---|
| Density | 8.75 | g/cm3 |
| Curie Temp | 460 | C |
| Elec. Resistivity | 0.56 | micro-ohm-m |
| Thermal Expansion | 12.5 | micro-m/m-C |
| Tensile Strength (Annealed) | 550-680 | MPa |
Heat Treatment: Hydrogen Annealing
Temperature: 1150-1200C (2100-2190F), soak 3-6 hours.
Atmosphere: Dry Hydrogen (Dew Point <=-60C) or Ultra-High Vacuum.
Cooling: Fast cool (>400C/h) to 600C, then controlled slow cool (100C/h) through the magnetic ordering zone to 400C.
Shock Warning: Once annealed, the material is extremely sensitive to mechanical shock. Any bending, dropping, or clamping will introduce internal stress and destroy the high permeability. All shaping must be done before the final anneal.
Industry Applications
| Industry | Component | Why 1J85? |
|---|---|---|
| Aerospace | Squid/Fluxgate magnetometer cores | Detects ultra-weak planetary/biological magnetic fields |
| High-End Audio | Moving-coil (MC) step-up transformer cores | Enhances micro-dynamics due to extremely narrow hysteresis |
| Medical | MEG shielding, MRI gradient coil shields | Attenuates urban magnetic noise for brain/cardiac diagnostics |
| Scientific | Electron microscope objective lens shields | Stabilizes electron beam path against ambient 50/60 Hz fields |
Quality Assurance (7-Stage)
- Carbon Check: VIM melt carbon <=0.015% internal.
- Purity: Sulfur and Oxygen monitored via ICP-MS.
- Hot Rolling: IR pyrometry, 4:1 reduction minimum.
- Cold Rolling: Precise dimensional tolerance +/- 0.002 mm for ribbon.
- H2 Anneal: Dew point monitored continuously (-60C minimum).
- Magnetic Testing: Epstein frame per GB/T 3658 on each lot.
- Packaging: Vacuum-sealed with VCI paper for corrosion protection.
Frequently Asked Questions
Q1: What is 1J85 used for?
Aerospace magnetometers, high-end audio step-up transformers, medical EEG/MEG room shielding, and electron microscope objective lens shields.
Q2: Is 1J85 better than 1J79?
1J85 has a slightly higher nickel content (81% vs 79%) and optimized Mo content, which can push maximum permeability to 500,000+ in ideal conditions. 1J79 is more cost-effective and easier to acquire; 1J85 is the premium option for maximum sensitivity.
Q3: Can I machine 1J85 after annealing?
Never. Drilling or machining 1J85 after the final H2 anneal introduces dislocations that destroy the magnetic properties. All machining must be done in the as-rolled (soft, 30 HRC) state.
Q4: What is the saturation flux?
~0.78 T (7,800 G). It is NOT a power alloy. If your application requires high flux handling, use 1J50 instead.
Q5: What heat treatment is required?
Hydrogen annealing at 1150-1200C with an ultra-dry atmosphere (dew point <= -60C).
Q6: Is it expensive?
Yes, containing ~81% high-purity nickel and 5% molybdenum. Cost is typically $30-55/kg EXW. Email sales@hangboalloy.com for a quote.
Q7: Is it available as thin ribbon?
Yes, Shanghai Hangbo supplies strip down to 0.02 mm thickness for toroidal core winding.
Q8: Does it rust?
Yes, the ~13% iron content is susceptible to humidity. Packed in vacuum-sealed bags.
Q9: Can I order internationally?
Yes, shipped FOB/CIF/DAP to 40+ countries. Full GB/T 14985 / EN 10204 3.1 certification provided.
Q10: What is the difference between 1J85 and Mu-metal?
They are functionally similar. "Mu-metal" is the Western trade name for the 80Ni-5Mo family, while 1J85 is the Chinese national standard (GB) equivalent with precisely defined chemistry.
Contact Shanghai Hangbo Alloy Group
| Channel | Details |
|---|---|
| Company | Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier |
| Website | www.nickel-alloy.com |
| sales@hangboalloy.com | |
| WhatsApp (Lisa) | +86 13611656360 |
| Address | Room 1508, No. 288 Shiyi Road, Baoshan District, Shanghai 200940, China |
Shanghai Hangbo Alloy Group - Complete Product Range
We supply the following alloy grades across all standard product forms.
| Family | Available Grades |
|---|---|
| Pure Nickel | NI200 (N02200), NI201 (N02201), N4, N5, N6 |
| Monel (Ni-Cu) | Monel 400, Monel 401, Monel 404, Monel K-500, Monel R-405 |
| Inconel (Ni-Cr) | Inconel 600, 601, 617, 625, 690, 718, X-750, 725 |
| Incoloy (Fe-Ni-Cr) | Incoloy 800, 800H, 800HT, 825, 925, 926, A-286, 25-6HN |
| Hastelloy (Ni-Mo-Cr) | Hastelloy C-276, C-22, C-2000, C-4, G-30, G-35, X, B-2, B-3, N |
| Nimonic (Ni-Cr-Co) | Nimonic 75, 80A, 90, 95, 105, 115, 263 |
| Haynes (High-Temp) | Haynes 25, 188, 230, 242, 282, 556 |
| Precision Alloys | 1J22 (Hiperco 50), 1J46, 1J50, 1J79, 1J85, 3J21, 4J32, 4J36 (Invar), 4J45 |
| High-Strength Alloys | 18Ni250 (Maraging 250), 18Ni300, AerMet 100, PH13-8Mo |
| Specialty Alloys | Alloy 20, Alloy 59, 254SMO, RA330, Inconel 686, 602CA, 713C, K403 |
Product Forms
| Product Form | Typical Size Range |
|---|---|
| Round Bars & Rods | Diameter 6 - 500 mm |
| Seamless Tubes & Pipes | OD 6 - 610 mm, WT 0.5 - 30 mm |
| Plates & Sheets | Thickness 0.1 - 100 mm |
| Forgings | Discs, Rings, Blocks, Tube Sheets |
| Welded Pipes | OD up to 1219 mm |
| Fittings & Flanges | Elbows, Tees, Reducers, Weld Neck, Slip-On |
| Wire & Welding Wire | Diameter 0.05 - 10 mm |
| Strip & Coil | Thickness 0.02 - 4.0 mm |
SGS / Bureau Veritas / TÜV Rheinland third-party inspection available on request.
Contact: sales@hangboalloy.com | WhatsApp (Lisa): +86 13611656360 | www.nickel-alloy.com
