Mu-Metal,Hy-Mu 80 Bar(Round bar, Flat bar),,E FORU

British Specs:，American Specs:MIL-N-14411 C ASTM A753，German Specs:

### **Mu-Metal / Hy-Mu 80 - Round Bar & Flat Bar Product Overview** **Mu-Metal**, commercially known as **Hy-Mu 80**, is a nickel-iron soft magnetic alloy renowned for its extremely high magnetic permeability and low coercivity. The **Round Bar** and **Flat Bar** forms provide versatile stock material for machining components requiring superior magnetic shielding properties and excellent soft magnetic characteristics. * **Common Names:** Mu-Metal Bar, Hy-Mu 80 Bar, High Permeability Alloy 80 Bar --- #### **1. Chemical Composition** Precisely controlled chemistry ensures optimal magnetic properties in bar products. | Element | Percentage (%) | Role in the Alloy | |:---|:---|:---| | **Nickel (Ni)** | 77.0 - 81.0 | Primary element for high permeability | | **Iron (Fe)** | Balance | Base magnetic element | | **Molybdenum (Mo)** | 4.50 - 5.50 | Enhances permeability and reduces coercivity | | **Copper (Cu)** | 0.10 - 0.30 | Improves corrosion resistance | | **Chromium (Cr)** | 0.10 - 0.30 | Enhances workability | | **Manganese (Mn)** | 0.30 - 0.60 | Deoxidizer and sulfur control | | **Silicon (Si)** | 0.10 - 0.30 | Improves magnetic properties | | **Carbon (C)** | 0.02 max | Minimized for optimal magnetic softness | --- #### **2. Physical Properties** Exceptional magnetic properties optimized for bar applications. | Property | Value / Condition | Notes | |:---|:---|:---| | **Density** | 8.75 g/cm³ (0.316 lb/in³) | | | **Melting Point** | ~1450 °C (2640 °F) | | | **Curie Temperature** | 410 - 430 °C (770 - 806 °F) | | | **Electrical Resistivity** | 0.58 μΩ·m at 20°C | | | **Thermal Conductivity** | 17 W/m·K at 20°C | | | **Thermal Expansion Coefficient** | 12.5 μm/m·°C (20-300°C) | | | **Specific Heat** | 0.46 J/g·°C at 20°C | | --- #### **3. Magnetic Properties** **Exceptional Magnetic Characteristics:** * **Initial Permeability (μi):** 30,000 - 50,000 (at 0.002T) * **Maximum Permeability (μmax):** 100,000 - 300,000 * **Saturation Induction (Bs):** 0.70 - 0.82 T (7,000 - 8,200 G) * **Coercive Force (Hc):** 0.8 - 1.6 A/m (0.01 - 0.02 Oe) * **Residual Induction (Br):** 0.20 - 0.40 T * **Hysteresis Loss:** Extremely low --- #### **4. Mechanical Properties (Annealed Condition)** **Round Bar Properties:** * **Tensile Strength:** 480-550 MPa (70-80 ksi) * **Yield Strength (0.2% Offset):** 250-320 MPa (36-46 ksi) * **Elongation:** 35-45% in 2 inches * **Reduction of Area:** 50-65% * **Hardness:** 65-80 HRB * **Modulus of Elasticity:** 150 GPa (21.8 × 10⁶ psi) **Flat Bar Properties:** * **Tensile Strength:** 470-540 MPa (68-78 ksi) * **Yield Strength:** 240-310 MPa (35-45 ksi) * **Elongation:** 30-40% in 2 inches * **Hardness:** 63-78 HRB --- #### **5. Product Specifications & Applications** **Round Bar Specifications:** * **Diameter Range:** 3.0 mm to 300 mm * **Diameter Tolerance:** ±0.1 mm (<25 mm), ±0.2% (>25 mm) * **Straightness:** ≤1 mm per meter * **Surface Finish:** 3.2 μm Ra standard, 1.6 μm Ra available **Flat Bar Specifications:** * **Thickness Range:** 3.0 mm to 100 mm * **Width Range:** 10 mm to 300 mm * **Thickness Tolerance:** ±0.15 mm (<10 mm), ±1.5% (>10 mm) * **Width Tolerance:** ±0.5 mm (<50 mm), ±1.0% (>50 mm) **Primary Applications:** **Round Bar Applications:** * **Magnetic Core Rods:** Precision cores for instruments and sensors * **Shielding Components:** Magnetic shielding rods and posts * **Sensor Elements:** Hall effect sensor components and flux concentrators * **Transformer Cores:** Specialized transformer core components * **Research Apparatus:** Components for physics research equipment **Flat Bar Applications:** * **Magnetic Base Plates:** Foundation plates for sensitive instruments * **Shielding Panels:** Flat magnetic shielding elements * **Structural Components:** Support elements requiring magnetic properties * **Fixture Bases:** Magnetic fixturing and tooling plates * **Calibration Standards:** Reference standards for magnetic measurements --- #### **6. International Standards** Comprehensive international specifications for bar products. | Standard Type | Standard Number | Title / Specification | |:---|:---|:---| | **ASTM** | **ASTM A753** | Standard Specification for Nickel-Iron Soft Magnetic Alloys | | **MIL-SPEC** | **MIL-N-14411C** | Composition 1, Grade 1 | | **AMS** | **AMS 7702** | Aerospace Material Specification | | **ASTM** | ASTM B48 | Standard Specification for Rod and Bar | | **IEC** | IEC 60404-8-6 | Metallic Magnetic Materials | | **DIN** | DIN 17745 | Nickel-Iron Alloys with Special Magnetic Properties | --- #### **7. Manufacturing & Processing** **Machining Characteristics:** * **Machinability Rating:** 25% (compared to 12114 steel) * **Recommended Tools:** Sharp carbide tools with positive rake angles * **Cutting Speeds:** 20-35 m/min for turning, 15-25 m/min for milling * **Feed Rates:** 0.08-0.25 mm/rev for turning, 0.05-0.15 mm/tooth for milling * **Coolant Requirements:** Essential for optimal tool life **Critical Heat Treatment:** * **Final Annealing:** 1100-1150°C in pure dry hydrogen atmosphere * **Stress Relief:** 400-500°C after machining operations * **Cooling Rate:** Controlled cooling >100°C/hour through 600-400°C range * **Atmosphere Control:** Essential for optimal magnetic properties **Special Handling Requirements:** * **Stress Avoidance:** Minimize mechanical stress after final anneal * **Proper Support:** Adequate support to prevent bending during storage * **Clean Handling:** Avoid contamination that could affect magnetic properties --- #### **8. Quality Assurance** * **Chemical Certification:** Mill certificate with heat analysis * **Dimensional Verification:** Statistical process control for size and straightness * **Magnetic Testing:** Permeability and coercive force measurement * **Mechanical Testing:** Tensile and hardness testing per ASTM standards * **Surface Quality:** Visual inspection and surface roughness measurement * **Traceability:** Full material traceability from melt to final product --- **Summary** **Mu-Metal (Hy-Mu 80) Round Bar and Flat Bar** provide essential stock materials for manufacturing precision components requiring the highest levels of magnetic permeability and shielding effectiveness. Their exceptional soft magnetic properties, combined with good machinability in the properly heat-treated condition, make them indispensable for sensitive instrumentation, aerospace systems, research equipment, and specialized industrial applications. The availability in both round and flat bar forms offers design flexibility for various component geometries while maintaining the superior magnetic characteristics that define Mu-Metal. Compliance with **ASTM A753** and other international standards ensures consistent material performance and reliability in applications where maximum permeability and minimum coercivity are essential. Proper processing and stress management are critical to preserve the exceptional magnetic properties throughout the manufacturing cycle.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 2536 gallon liquid totes Special package is available on request.