Elektron W7 Magnesium Alloy， RZ5 (ZE41),E FOUR

### **Elektron W7 / RZ5 (ZE41) Magnesium Alloy** **Product Overview** Elektron W7, commercially designated as RZ5 or ZE41, is a medium-strength magnesium-zinc-rare earth-zirconium casting alloy that offers a good balance of room temperature properties and improved elevated temperature performance compared to standard magnesium-aluminum alloys. Developed as one of the early creep-resistant magnesium alloys, RZ5 provides reliable service up to approximately 150-175°C while maintaining good castability, corrosion resistance, and mechanical properties. The alloy has established itself as a proven material for aerospace applications where weight reduction and moderate temperature capability are required. This alloy is typically supplied as sand castings and investment castings, with properties optimized through T5 or T6 heat treatment. --- #### **1. Chemical Composition** RZ5 features a zinc-rare earth-zirconium system designed for balanced performance. | Element | Composition (% by Weight) | | :---------------- | :-------------------------------- | | **Zinc (Zn)** | 3.5 - 5.0 % | | **Rare Earths (RE)*** | 0.8 - 1.7 % | | **Zirconium (Zr)** | 0.4 - 1.0 % | | **Copper (Cu)** | ≤ 0.10 % | | **Iron (Fe)** | ≤ 0.03 % | | **Nickel (Ni)** | ≤ 0.003 % | | **Silicon (Si)** | ≤ 0.05 % | | **Other Impurities** | ≤ 0.30 % (each) | | **Magnesium (Mg)** | Balance | *Note:* The "Rare Earths" typically consist of cerium-based mischmetal. **Zinc** provides solid solution strengthening, while **rare earths** enhance elevated temperature performance through stable intermetallic formation. **Zirconium** serves as an effective grain refiner, improving both strength and ductility. --- #### **2. Physical & Mechanical Properties** RZ5 offers a balanced combination of mechanical properties with moderate elevated temperature capability. **Physical Properties:** * **Density:** 1.82 g/cm³ (0.066 lb/in³) * **Melting Range:** 550 - 640 °C (1022 - 1184 °F) * **Coefficient of Thermal Expansion:** 26.0 μm/m·°C (20-200°C) * **Thermal Conductivity:** 113 W/m·K **Typical Mechanical Properties (T6 Temper):** * **Ultimate Tensile Strength (UTS):** 215 - 235 MPa (31 - 34 ksi) * **Tensile Yield Strength (TYS):** 155 - 175 MPa (22 - 25 ksi) * **Elongation:** 3 - 6% * **Compressive Yield Strength:** 155 - 175 MPa (22 - 25 ksi) * **Shear Strength:** 115 - 135 MPa (17 - 20 ksi) * **Hardness:** 65 - 75 HBW * **Modulus of Elasticity:** 45 GPa (6.5 × 10³ ksi) **Elevated Temperature Performance:** * **Useful creep resistance up to 150-175°C (302-347°F)** * **Good strength retention at elevated temperatures** * **Stable microstructure under prolonged thermal exposure** * **Better high-temperature performance than AZ-series alloys** --- #### **3. International Standards & Specifications** RZ5 is recognized by multiple international standards organizations. * **ASTM International:** **ASTM B80 ZE41A-T5** (Standard Specification for Magnesium-Alloy Sand Castings) * **Aerospace Material Specification:** **AMS 4435** * **SAE International:** **SAE J465** * **UNS Designation:** **UNS M16410** * **British Standards:** **BS 2970 MAG-4** * **German Standards:** **DIN MgZn5RE1Zr** * **French Standards:** **AFNOR G-Z5Zr1RE** * **Proprietary Designation:** **Elektron W7 / RZ5** (Luxfer MEL Technologies) --- #### **4. Product Applications** RZ5 has been historically important in aerospace and continues to be used in specific applications. * **Aerospace & Defense:** * **Helicopter Transmission Housings** * **Gearbox Casings and Components** * **Engine Accessory Housings** * **Aircraft Wheel Housings** * **Missile Components and Structures** * **Industrial Applications:** * **High-Speed Machinery Components** * **Compressor Housings** * **Industrial Gearbox Casings** * **Specialized Equipment Housings** * **Racing & High-Performance:** * **Racing Engine Components** * **Motorsport Transmission Casings** * **High-Performance Automotive Parts** --- #### **5. Manufacturing Characteristics** **Casting Performance:** * Good castability with adequate fluidity * Requires proper zirconium grain refinement * Suitable for sand, permanent mold, and investment casting * Good dimensional stability * Moderate solidification shrinkage **Secondary Processing:** * Good machinability with proper techniques * Responsive to heat treatment * Requires appropriate corrosion protection * Suitable for various surface treatments * Good weldability with proper procedures --- **Summary** **Elektron W7 / RZ5 (ZE41) Magnesium Alloy** represents an important development in magnesium alloy technology, being one of the first commercially successful zinc-rare earth-zirconium casting alloys. Its balanced composition provides good **room temperature strength**, **moderate elevated temperature capability**, and **reliable performance** in demanding applications. While newer alloys like WE43 and QE22 offer superior high-temperature performance, RZ5 maintains relevance due to its established manufacturing history, cost-effectiveness, and proven reliability in aerospace applications. Compliance with standards such as **AMS 4435** and **ASTM B80** ensures its continued use in certified components, particularly in legacy systems and applications where its specific performance characteristics have been thoroughly validated through decades of successful service experience.

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 3413 gallon liquid totes Special package is available on request.