Magnesium AZ81A-T4, Cast,E FOUR

Product Datasheet: Magnesium Alloy AZ81A-T4 (Cast), UNS M11810** **Overview** Magnesium Alloy AZ81A is a versatile, corrosion-resistant magnesium-aluminum-zinc alloy primarily produced via sand casting and permanent mold casting processes. The **-T4** temper designation indicates that the cast component has been **solution heat-treated and naturally aged**. This process involves heating the casting to a high temperature to dissolve alloying elements into the magnesium matrix, followed by quenching and then aging at room temperature. This treatment significantly enhances tensile strength and ductility compared to the as-cast (F) condition. AZ81A-T4 offers an excellent balance of strength, castability, and corrosion resistance, making it a popular choice for a wide range of structural applications where weight reduction is critical. **Key Advantages** * **Good Strength-to-Weight Ratio:** Provides substantial weight savings over aluminum and steel, being approximately 35% lighter than aluminum and 75% lighter than steel. * **Improved Ductility and Toughness:** The T4 heat treatment increases elongation, resulting in components that can better absorb impact and deformation. * **Excellent Castability:** It flows well into molds, making it suitable for producing complex and thin-walled castings. * **Good Corrosion Resistance:** Among the magnesium-aluminum series, AZ81A offers respectable corrosion resistance, especially in the T4 condition, which creates a more homogeneous microstructure. * **Good Machinability:** Can be machined at very high speeds with excellent surface finish and low tool pressure. **Chemical Composition (Weight % per ASTM B80)** The composition is tightly controlled to ensure optimal performance and corrosion resistance. | Element | Content (%) | Element | Content (%) | | :--- | :--- | :--- | :--- | | **Aluminum (Al)** | 7.0 - 8.1 | **Zinc (Zn)** | 0.40 - 1.0 | | **Manganese (Mn)** | 0.13 - 0.50 | **Silicon (Si)** | ≤ 0.30 | | **Copper (Cu)** | ≤ 0.10 | **Iron (Fe)** | ≤ 0.005 | | **Nickel (Ni)** | ≤ 0.01 | **Other Impurities** | ≤ 0.30 | | **Magnesium (Mg)** | Balance | | | *Note: The very low limits on impurities like Iron (Fe), Nickel (Ni), and Copper (Cu) are crucial for achieving the alloy's enhanced corrosion resistance.* **Physical & Mechanical Properties (Typical for Sand Cast T4 Condition)** The following values are representative and can vary based on the casting method, section size, and foundry practice. | Property | Metric Unit | Imperial Unit | | :--- | :--- | :--- | | **Density** | 1.80 g/cm³ | 0.065 lb/in³ | | **Melting Range** | ~ 525 - 610 °C | ~ 977 - 1130 °F | | **Ultimate Tensile Strength (UTS)** | 240 - 275 MPa | 35 - 40 ksi | | **Tensile Yield Strength (0.2% Offset)** | 75 - 105 MPa | 11 - 15 ksi | | **Elongation (in 50 mm / 2 in)** | 12 - 18 % | 12 - 18 % | | **Compressive Yield Strength** | 75 - 105 MPa | 11 - 15 ksi | | **Shear Strength** | ~ 125 MPa | ~ 18 ksi | | **Hardness (Brinell)** | 50 - 60 HB | 50 - 60 HB | | **Modulus of Elasticity** | 45 GPa | 6.5 x 10⁶ psi | | **Fatigue Strength (Rotating Beam, 5x10⁸ cycles)** | ~ 90 MPa | ~ 13 ksi | **International Standards** Magnesium AZ81A-T4 castings are covered by the following international standards: * **ASTM International:** * **ASTM B80:** Standard Specification for Magnesium-Alloy Sand Castings. This is the primary standard governing the composition and properties of AZ81A castings. * **ASTM B93/B93M:** Standard Specification for Magnesium Alloys in Ingot Form for Sand Castings, Permanent Mold Castings, and Die Castings. * **SAE International:** * **SAE AMS 4435:** Covers Magnesium Alloy Sand Castings (AZ81A-T4). * **Unified Numbering System (UNS):** * **UNS M11810** * **European Standards (Similar Designations):** * **EN 1753:** Mg-Al8Zn (Designation for a similar alloy family). **Product Applications** The combination of castability, good mechanical properties, and light weight makes AZ81A-T4 suitable for a variety of applications across several industries. * **Aerospace:** * Aircraft canopy frames, transmission housings, and accessory gearbox cases. * Internal brackets and support structures for avionics. * **Defense:** * Lightweight chassis and housings for portable communication and radar equipment. * Components for guided weapons and optical sighting systems. * **Industrial & Commercial:** * Housing and parts for power tools, reducing operator fatigue. * Components for textile and printing machinery. * Brackets and frames for electronic enclosures requiring EMI/RFI shielding. * **Transportation:** * Automotive components such as clutch housings, bracket assemblies, and intake manifolds (for non-high-heat applications). **Handling & Considerations** * **Corrosion Protection:** While AZ81A has good inherent corrosion resistance, for harsh environments (e.g., marine, road salt), a protective coating system (e.g., chemical conversion coating, anodizing, paint, or powder coat) is recommended. * **High-Temperature Use:** The strength of AZ81A decreases significantly at temperatures above approximately 120°C (250°F). It is not recommended for prolonged high-temperature service. * **Comparison to AZ91:** AZ81A has a slightly lower aluminum content than the more common AZ91D die-casting alloy. This results in slightly lower strength but significantly improved ductility and toughness, especially in the T4 temper. --- **Disclaimer:** The information provided herein is for reference purposes only. Material properties can vary based on the specific casting process, section size, and foundry. For critical applications, consult the relevant material standards (e.g., ASTM B80) and the component manufacturer for certified test data.

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 3309 gallon liquid totes Special package is available on request.