Elektron W18 Magnesium Alloy， AZ91,E FOUR

### **Elektron W18 / AZ91 Magnesium Alloy** **Product Overview** Elektron W18, commercially designated as AZ91, is the most widely used and commercially important magnesium casting alloy globally. Belonging to the Mg-Al-Zn system, AZ91 offers an exceptional balance of castability, mechanical properties, and corrosion resistance, making it the benchmark for general-purpose magnesium die castings. The alloy combines excellent strength-to-weight ratio with good manufacturing characteristics, establishing itself as the primary choice for high-volume production across automotive, electronics, and consumer goods industries. This alloy is typically supplied as high-pressure die castings, sand castings, and permanent mold castings, with the high-purity version (AZ91E) providing enhanced corrosion resistance for demanding applications. --- #### **1. Chemical Composition** AZ91 features an optimized aluminum-zinc composition with controlled impurity levels. | Element | Composition (% by Weight) | | :---------------- | :-------------------------------- | | **Aluminum (Al)** | 8.3 - 9.7 % | | **Zinc (Zn)** | 0.35 - 1.0 % | | **Manganese (Mn)** | 0.13 - 0.50 % | | **Silicon (Si)** | ≤ 0.20 % | | **Copper (Cu)** | ≤ 0.10 % | | **Iron (Fe)** | ≤ 0.005 % | | **Nickel (Ni)** | ≤ 0.002 % | | **Other Impurities** | ≤ 0.02 % (each) | | **Magnesium (Mg)** | Balance | *Note:* The **aluminum** content provides excellent castability and strength through the formation of Mg₁₇Al₁₂ precipitates. **Zinc** enhances strength and fluidity, while **manganese** improves corrosion resistance by combining with iron impurities. High-purity versions feature stricter controls on iron, copper, and nickel content. --- #### **2. Physical & Mechanical Properties** AZ91 offers a well-balanced property profile suitable for a wide range of applications. **Physical Properties:** * **Density:** 1.81 g/cm³ (0.065 lb/in³) * **Melting Range:** 470 - 595 °C (878 - 1103 °F) * **Coefficient of Thermal Expansion:** 26.0 μm/m·°C (20-200°C) * **Thermal Conductivity:** 51 W/m·K * **Specific Heat Capacity:** 1050 J/kg·K **Typical Mechanical Properties (As-Die Cast):** * **Ultimate Tensile Strength (UTS):** 230 - 250 MPa (33 - 36 ksi) * **Tensile Yield Strength (TYS):** 150 - 170 MPa (22 - 25 ksi) * **Elongation:** 3 - 7% * **Compressive Yield Strength:** 150 - 170 MPa (22 - 25 ksi) * **Shear Strength:** 130 - 140 MPa (19 - 20 ksi) * **Hardness:** 65 - 75 HBW * **Modulus of Elasticity:** 45 GPa (6.5 × 10³ ksi) **Elevated Temperature Performance:** * **Useful mechanical properties up to 120°C (248°F)** * **Good creep resistance below 100°C** * **Gradual strength reduction above 120°C** * **Adequate performance for most automotive and consumer applications** --- #### **3. International Standards & Specifications** AZ91 is recognized by all major international standards organizations. * **ASTM International:** **ASTM B94** (Standard Specification for Magnesium-Alloy Die Castings) * **ISO Standards:** **ISO 16220** (Magnesium and magnesium alloys - Castings) * **SAE International:** **SAE J465** * **UNS Designation:** **UNS M11917** * **German Standards:** **DIN MgAl9Zn1** * **Japanese Standards:** **JIS H 5303** * **Chinese Standards:** **GB/T 19078** * **Proprietary Designation:** **Elektron AZ91** / **W18** (Luxfer MEL Technologies) --- #### **4. Product Applications** AZ91 finds extensive use across multiple industries due to its versatile properties. * **Automotive Industry:** * **Transmission Housings and Components** * **Intake Manifolds and Throttle Bodies** * **Steering Wheel Cores and Columns** * **Seat Frames and Adjusters** * **Bracket and Mounting Systems** * **Electronics & Consumer Goods:** * **Laptop Computer Housings and Chassis** * **Digital Camera Bodies and Frames** * **Power Tool Housings and Components** * **Portable Electronic Device Enclosures** * **Aerospace & Defense:** * **Aircraft Instrument Housings** * **Avionics Equipment Casings** * **Military Communication Equipment** * **Industrial Applications:** * **Power Tool Components** * **Material Handling Equipment Parts** * **Textile Machinery Components** * **Office Equipment Housings** --- #### **5. Manufacturing Characteristics** **Die Casting Performance:** * Excellent fluidity for thin-walled castings (down to 1.0 mm) * Good hot tearing resistance * Low solidification shrinkage * Excellent dimensional stability * Fast cycling times in high-pressure die casting **Secondary Processing:** * Excellent machinability with high surface quality * Good response to various surface treatments * Compatibility with conversion coatings and painting systems * Good weldability using TIG and MIG processes * Suitable for various finishing operations --- **Summary** **Elektron W18 / AZ91 Magnesium Alloy** stands as the industry standard for magnesium die castings, offering an unparalleled combination of **mechanical properties**, **exceptional castability**, and **cost-effectiveness**. Its well-balanced **aluminum-zinc-manganese** system provides good strength-to-weight ratio, reliable performance, and adequate corrosion resistance for most applications. The alloy's compliance with major international standards including **ASTM B94**, **ISO 16220**, and various automotive specifications ensures consistent quality and reliability across global supply chains. As the most specified magnesium die casting alloy worldwide, AZ91 continues to drive the adoption of magnesium components across automotive, electronics, and industrial sectors, providing engineers with a proven, reliable material solution for weight reduction and performance enhancement in high-volume production applications. Its versatility and well-understood behavior make it the first choice for introducing magnesium components into new applications.

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 3419 gallon liquid totes Special package is available on request.