Magnesium AZ31B T1 Wrought Alloy (UNS M11311)， UNS M11311， Mg-3Al-1Zn,E FOUR

Magnesium AZ31B (UNS M11311) Wrought Alloy Product Introduction** **Product Description:** Magnesium AZ31B is one of the most commercially popular and widely used wrought magnesium alloys. Designated as **UNS M11311**, it offers an excellent combination of strength, ductility, and corrosion resistance among standard magnesium alloys. The "T1" temper indicates that it has been cooled from an elevated-temperature shaping process and naturally aged to a substantially stable condition. Its common nomenclature, **Mg-3Al-1Zn**, directly reflects its primary alloying elements. AZ31B is renowned for its very low density, high specific strength, and good machinability, making it a prime candidate for lightweight structural applications. --- #### **1. Chemical Composition (Weight %)** The typical chemical composition of AZ31B alloy conforms to the following international standards: | Element | Minimum (%) | Maximum (%) | Key Function | | :--- | :--- | :--- | :--- | | **Aluminum (Al)** | 2.5 | 3.5 | Primary strengthener, improves castability and strength. | | **Zinc (Zn)** | 0.6 | 1.4 | Enhances strength and corrosion resistance. | | **Manganese (Mn)** | 0.2 | 1.0 | Improves corrosion resistance, particularly against saltwater. | | **Silicon (Si)** | - | 0.10 | Impurity control. | | **Copper (Cu)** | - | 0.05 | Impurity control (minimized for corrosion resistance). | | **Iron (Fe)** | - | 0.005 | Impurity control (strictly limited for corrosion resistance). | | **Nickel (Ni)** | - | 0.005 | Impurity control (strictly limited for corrosion resistance). | | **Other Elements** | - | 0.30 (total) | - | | **Magnesium (Mg)** | **Balance** | | | *Note: Strict control of Fe, Cu, and Ni impurities is critical for maintaining the alloy's corrosion performance.* --- #### **2. Physical Properties** | Property | Value / Description | Condition | | :--- | :--- | :--- | | **Density** | 1.77 g/cm³ (0.064 lb/in³) | At 20°C | | **Melting Point** | ~ 605 - 630 °C (1121 - 1166 °F) | - | | **Thermal Conductivity** | 76 - 96 W/m·K | At 25°C | | **Coefficient of Thermal Expansion** | 26.0 μm/m·°C | 20 - 100°C | | **Electrical Resistivity** | ~ 92 nΩ·m | At 20°C | | **Modulus of Elasticity** | 45 GPa (6.5 x 10⁶ psi) | - | | **Shear Modulus** | 17 GPa (2.4 x 10⁶ psi) | - | | **Poisson's Ratio** | 0.35 | - | --- #### **3. Mechanical Properties (Typical for T1 Temper - Sheet/Plate)** Mechanical properties vary with product form (sheet, plate, extrusion) and exact temper. | Property | Typical Value (Sheet) | | :--- | :--- | | **Tensile Strength** | 255 MPa (37 ksi) | | **Yield Strength (0.2% Offset)** | 150 MPa (22 ksi) | | **Elongation** | 12 - 21% | | **Compressive Yield Strength** | 110 MPa (16 ksi) | | **Hardness** | 55 HB | --- #### **4. International Standards** AZ31B is specified in numerous international standards across different product forms. | Standard Organization | Standard Designation for AZ31B | | :--- | :--- | | **ASTM International** | **ASTM B90** (Sheet and Plate)
**ASTM B107/B107M** (Extruded Rod, Bar, Shapes) | | **SAE International** | **SAE J465** | | **UNS (Unified Numbering System)** | **M11311** | | **ISO (International Org. for Standardization)** | **ISO 3116** (Wrought Magnesium and Magnesium Alloys) | | **AMS (Aerospace Material Spec.)** | **AMS 4375** (Sheet and Plate) | --- #### **5. Product Applications** The high strength-to-weight ratio and good formability of AZ31B make it suitable for a wide range of lightweight applications: * **Aerospace:** * Aircraft skin and body panels * Internal brackets and components * Covers and housings for avionics * **Automotive:** * Seat frames * Steering wheel cores * Transmission housings * Inner door frames * **Electronics:** * Laptop and tablet casings * Housing for cameras and projectors * Frames for portable electronic devices * **General Industry:** * Portable tools and equipment housings (e.g., chain saws, drills) * Material handling components * Sporting goods (e.g., baseball bats, climbing equipment) --- #### **6. Key Characteristics & Considerations** * **Advantages:** * **Extremely Lightweight:** Approximately 35% lighter than aluminum and 78% lighter than steel. * **High Specific Strength:** Excellent strength-to-weight ratio. * **Good Machinability:** Can be machined at high speeds with excellent surface finish. * **Good Damping Capacity:** Effectively absorbs vibration and noise. * **Good Formability (at elevated temps):** Can be hot formed into complex shapes. * **Considerations:** * **Corrosion:** Requires protective coatings or cladding for use in severe (e.g., salt-spray) environments, though its performance is good in normal atmospheres. * **Low Strength at High Temperatures:** Mechanical properties degrade significantly above ~120°C (250°F). * **Flammability:** Fine chips and powder can be flammable; proper machining practices are essential. In summary, **Magnesium AZ31B (UNS M11311)** is a versatile and high-performance wrought alloy that serves as a cornerstone material for weight-critical applications across the aerospace, automotive, and electronics industries.

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 3291 gallon liquid totes Special package is available on request.