Elektron AZ31B Magnesium Extrusion Alloy, UNS M11311，AMS 4375; AMS 4376; AMS 4377; AMS 4382; ASTM B90,E FOUR

### **Elektron AZ31B Magnesium Extrusion Alloy (UNS M11311)** **Product Overview** Elektron AZ31B is a versatile magnesium-aluminum-zinc wrought alloy that represents one of the most widely used and commercially important magnesium extrusion alloys. Known for its excellent combination of strength, ductility, formability, and corrosion resistance, AZ31B serves as the workhorse alloy for magnesium extrusions across multiple industries. The alloy offers a favorable strength-to-weight ratio, good weldability, and reliable performance in various environmental conditions, making it particularly suitable for structural applications where weight reduction is critical. This alloy is commonly supplied in extruded forms such as rods, bars, profiles, tubes, and structural shapes, and is available in various tempers including F (as-fabricated) and H24 (strain-hardened and partially annealed). --- #### **1. Chemical Composition** The composition of AZ31B is balanced to provide optimal mechanical properties and corrosion resistance. | Element | Composition (% by Weight) | | :---------------- | :-------------------------------- | | **Aluminum (Al)** | 2.5 - 3.5 % | | **Zinc (Zn)** | 0.6 - 1.4 % | | **Manganese (Mn)** | 0.20 - 0.50 % | | **Copper (Cu)** | ≤ 0.05 % | | **Iron (Fe)** | ≤ 0.05 % | | **Nickel (Ni)** | ≤ 0.005 % | | **Silicon (Si)** | ≤ 0.10 % | | **Calcium (Ca)** | ≤ 0.04 % | | **Other Impurities** | ≤ 0.30 % (each) | | **Magnesium (Mg)** | Balance | *Note:* The **aluminum** content provides solid solution strengthening, while **zinc** enhances strength and improves the alloy's response to strain hardening. **Manganese** plays a crucial role in improving corrosion resistance by combining with iron impurities to form harmless intermetallic compounds. --- #### **2. Physical & Mechanical Properties** AZ31B exhibits a well-balanced property profile that makes it suitable for a wide range of applications. **Physical Properties:** * **Density:** 1.77 g/cm³ (0.064 lb/in³) * **Melting Range:** 605 - 630 °C (1121 - 1166 °F) * **Coefficient of Thermal Expansion:** 26.0 μm/m·°C (20-200°C) * **Thermal Conductivity:** 96 W/m·K * **Modulus of Elasticity:** 45 GPa (6.5 × 10³ ksi) **Typical Mechanical Properties (H24 Temper - Extruded):** * **Ultimate Tensile Strength (UTS):** 235 - 260 MPa (34 - 38 ksi) * **Tensile Yield Strength (TYS):** 145 - 165 MPa (21 - 24 ksi) * **Elongation:** 8 - 15% * **Compressive Yield Strength:** 95 - 115 MPa (14 - 17 ksi) * **Shear Strength:** 130 - 150 MPa (19 - 22 ksi) * **Fatigue Strength:** 110 - 130 MPa (16 - 19 ksi) **Elevated Temperature Performance:** * **Maintains useful mechanical properties up to 100°C (212°F)** * **Good formability at elevated temperatures (200-300°C)** * **Gradual strength reduction above 100°C** --- #### **3. International Standards & Specifications** AZ31B is comprehensively covered by multiple international standards, particularly in aerospace specifications. * **Unified Numbering System (UNS):** **UNS M11311** * **Aerospace Material Specification (AMS):** * **AMS 4375** (Extruded Bars, Rods, and Shapes) * **AMS 4376** (Extruded Bars and Shapes, Solution Heat Treated) * **AMS 4377** (Sheet and Plate) * **AMS 4382** (Extruded Structural Shapes) * **ASTM International:** **ASTM B90** (Standard Specification for Magnesium-Alloy Sheet and Plate) * **SAE International:** **SAE J465** * **Federal Standard:** **QQ-M-44** * **European Standards:** **EN 1753 Mg-Al3Zn1** --- #### **4. Product Applications** AZ31B finds extensive use across aerospace, automotive, electronics, and general industrial sectors. * **Aerospace & Defense:** * **Aircraft Fuselage Components** * **Interior Aircraft Parts** * **Helicopter Transmission Housings** * **Missile Body Sections** * **Electronic Equipment Enclosures** * **Automotive & Transportation:** * **Seat Frames** * **Steering Wheel Components** * **Instrument Panel Structures** * **Bicycle Frames and Components** * **Electronics & Consumer Goods:** * **Laptop Computer Housings** * **Camera Bodies** * **Portable Power Tool Casings** * **Sports Equipment** * **Industrial Applications:** * **Material Handling Equipment** * **Work Platform Components** * **Portable Scaffolding Systems** --- #### **5. Manufacturing Characteristics** **Extrusion Performance:** * Excellent extrudability with good surface finish * Capable of producing complex thin-walled profiles * Suitable for high-speed extrusion processes **Secondary Processing:** * **Good weldability** using TIG and MIG processes * **Excellent formability** at elevated temperatures * **Good machinability** with proper techniques * Responsive to various surface treatments and coatings --- **Summary** **Elektron AZ31B (UNS M11311)** stands as the fundamental magnesium extrusion alloy that has enabled widespread adoption of magnesium in structural applications. Its balanced **aluminum-zinc-manganese** composition provides an optimal combination of **medium strength**, **good ductility**, and **excellent corrosion resistance** for a wrought magnesium alloy. The comprehensive coverage by multiple **AMS standards (4375, 4376, 4377, 4382)** and **ASTM B90** certifies its reliability for critical aerospace and industrial applications. While newer alloys offer higher strength or better elevated temperature performance, AZ31B remains the most versatile and widely specified magnesium extrusion alloy, valued for its consistent performance, excellent manufacturability, and proven track record across diverse industries seeking weight reduction solutions.

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 3403 gallon liquid totes Special package is available on request.