Elektron EQ21 Magnesium Casting Alloy, UNS M18330,E FOUR

Elektron EQ21 Magnesium Casting Alloy (UNS M18330)** **Product Overview** Elektron EQ21 is a premium, high-performance magnesium casting alloy specifically engineered for exceptional strength and outstanding creep resistance at elevated temperatures (up to 300°C / 572°F). It belongs to the family of magnesium-rare earth (Mg-RE) alloys and is designed to meet the demanding requirements of the aerospace and high-performance motorsport industries. Unlike standard alloys like AZ91, EQ21 achieves its properties through a sophisticated combination of silver (Ag) and rare earth elements, which form stable strengthening precipitates. This alloy is suitable for use in sand castings, permanent mold castings, and investment castings for critical components operating under high thermal and mechanical stress. --- #### **1. Chemical Composition** The composition of Elektron EQ21 is carefully balanced to optimize high-temperature performance and castability. | Element | Composition (% by Weight) | | :--- | :--- | | **Silver (Ag)** | 1.3 - 2.5 % | | **Rare Earths (RE)*** | 1.5 - 3.0 % | | **Zirconium (Zr)** | 0.4 - 1.0 % | | **Thorium (Th)** | ≤ 0.3 % (Typically absent in modern versions) | | **Zinc (Zn)** | ≤ 0.3 % | | **Manganese (Mn)** | ≤ 0.3 % | | **Copper (Cu)** | ≤ 0.03 % | | **Iron (Fe)** | ≤ 0.03 % | | **Nickel (Ni)** | ≤ 0.003 % | | **Silicon (Si)** | ≤ 0.03 % | | **Other Impurities** | ≤ 0.30 % (each) | | **Magnesium (Mg)** | Balance | *Note:* The "Rare Earths" are typically a blend of Neodymium (Nd) and Gadolinium (Gd). Zirconium (Zr) acts as a powerful grain refiner. The presence of Silver (Ag) significantly enhances age-hardening response and strength. --- #### **2. Physical & Mechanical Properties** Elektron EQ21 exhibits a superior property profile, particularly at elevated temperatures, after a full T6 heat treatment (solution heat treatment and aging). **Physical Properties:** * **Density:** ~1.82 g/cm³ (0.065 lb/in³) - Maintains the classic lightweight advantage of magnesium. * **Melting Range:** ~ 545 - 640 °C (1013 - 1184 °F) **Typical Mechanical Properties (at Room Temperature, T6 Condition):** * **Ultimate Tensile Strength (UTS):** 240 - 260 MPa (35 - 38 ksi) * **Tensile Yield Strength (TYS):** 185 - 205 MPa (27 - 30 ksi) * **Elongation:** 2 - 5% * **Shear Strength:** ~ 125 MPa (18 ksi) **Elevated Temperature Performance (Key Advantage):** The primary strength of EQ21 is its retention of mechanical properties and resistance to creep under sustained load at high temperatures. * **Creep Resistance:** Excellent up to **300°C (572°F)**. * **Strength at 200°C (392°F):** Retains a significant portion of its room temperature yield strength. * **Strength at 250°C (482°F):** Maintains useful load-bearing capacity where most common magnesium alloys would fail. --- #### **3. International Standards & Specifications** Elektron EQ21 is covered by several key international and aerospace standards. * **Unified Numbering System (UNS):** **UNS M18330** * **Aerospace Material Specification (AMS):** **AMS 4429** (This is the primary specification for sand castings of this alloy) * **ASTM International:** **ASTM B80** (Referenced for sand casting specifications) * **Proprietary Designation:** **Elektron EQ21** is a registered trademark of Luxfer MEL Technologies, a leading developer and producer of advanced magnesium alloys. --- #### **4. Product Applications** Due to its high-temperature capability and specific strength, EQ21 is used in the most demanding applications, primarily in aerospace and racing. * **Aerospace & Gas Turbine Engines:** * **Engine Casings:** Intermediate and compressor casings for gas turbine engines. * **Transmission Housings:** Gearboxes and accessory drive housings within the engine core. * **Engine Accessories:** Mounts and brackets subjected to high heat. * **Defense:** * Components for missile systems, jet engine parts, and other military aerospace applications. * **High-Performance Motorsports:** * **Formula 1 & Motorsports:** Gearbox casings, turbocharger housings, and other powertrain components exposed to high temperatures. --- **Summary** **Elektron EQ21 (UNS M18330)** is a specialized, high-performance casting alloy that pushes the boundaries of magnesium's operational temperature range. Its sophisticated chemistry, leveraging silver and rare earth elements, provides a unique combination of lightweight properties and exceptional creep resistance up to 300°C. Governed by stringent standards like **AMS 4429**, it is the material of choice for critical components in aerospace propulsion systems and other extreme environments where weight savings at high temperatures are paramount.

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 3390 gallon liquid totes Special package is available on request.