Magnesium AZ91C-T6, Cast，UNS M1180,E FOUR

*Product Datasheet: Magnesium Alloy AZ91C-T6 (Cast), UNS M11910** **1. Overview** Magnesium Alloy AZ91C is a high-strength, corrosion-resistant magnesium-aluminum-zinc alloy primarily produced via sand casting and permanent mold casting. The **"T6"** temper designation indicates that the castings have undergone a full heat treatment comprising **Solution Heat Treatment, Quenching, and Artificial Aging**. This T6 thermal treatment significantly enhances the alloy's mechanical properties—particularly its ultimate tensile strength and yield strength—by dissolving soluble elements and then precipitating them as fine, strengthening intermetallic phases. While newer, higher-purity variants like AZ91E have become more common for critical applications, AZ91C remains a historically important and widely specified alloy for high-integrity cast components. **2. Key Advantages** * **Excellent Strength-to-Weight Ratio:** Offers high specific strength, being about 35% lighter than aluminum and 75% lighter than steel. * **Good Castability:** Exhibits excellent fluidity, low shrinkage, and is well-suited for producing complex and thin-walled sand and permanent mold castings. * **Good Corrosion Resistance:** Provides respectable resistance to atmospheric corrosion, though it is generally inferior to modern high-purity grades like AZ91E due to higher impurity limits. * **Good Machinability:** Can be machined at very high speeds with an excellent surface finish and low cutting force requirements. * **Good Damping Capacity:** Effectively absorbs vibrational energy and reduces noise. **3. Chemical Composition (Weight % per ASTM B80)** The composition is controlled to balance castability, strength, and corrosion resistance. | Element | Content (%) | Element | Content (%) | | :--- | :--- | :--- | :--- | | **Aluminum (Al)** | 8.3 - 9.2 | **Zinc (Zn)** | 0.45 - 0.9 | | **Manganese (Mn)** | 0.13 - 0.50 | **Silicon (Si)** | ≤ 0.30 | | **Copper (Cu)** | ≤ 0.25 | **Iron (Fe)** | ≤ 0.05 | | **Nickel (Ni)** | ≤ 0.03 | **Other Impurities** | ≤ 0.30 | | **Magnesium (Mg)** | Balance | | | *Note: Compared to high-purity grade AZ91E, AZ91C has higher allowable limits for impurities like Iron (Fe), Nickel (Ni), and Copper (Cu). These higher impurity levels can form active cathodic sites, which may reduce the alloy's overall corrosion resistance, particularly in saltwater environments.* **4. Physical & Mechanical Properties (Typical for Sand Cast T6 Temper)** The following values are representative and can vary based on the casting method, section size, and foundry practice. | Property | Metric Unit | Imperial Unit | | :--- | :--- | :--- | | **Density** | 1.81 g/cm³ | 0.065 lb/in³ | | **Melting Range** | ~ 470 - 595 °C | ~ 878 - 1103 °F | | **Ultimate Tensile Strength (UTS)** | 275 - 310 MPa | 40 - 45 ksi | | **Tensile Yield Strength (0.2% Offset)** | 150 - 165 MPa | 22 - 24 ksi | | **Elongation (in 50 mm / 2 in)** | 3 - 6 % | 3 - 6 % | | **Compressive Yield Strength** | 150 - 165 MPa | 22 - 24 ksi | | **Shear Strength** | ~ 145 MPa | ~ 21 ksi | | **Hardness (Brinell)** | 70 - 80 HB | 70 - 80 HB | | **Modulus of Elasticity** | 45 GPa | 6.5 x 10⁶ psi | | **Fatigue Strength (Rotating Beam, 5x10⁸ cycles)** | ~ 100 MPa | ~ 14.5 ksi | **5. International Standards** Magnesium AZ91C-T6 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 AZ91C castings. * **SAE International:** * **SAE AMS 4435 (Historical):** While often associated with AZ91A/E, the standard historically covered AZ91-type alloys for sand castings. For AZ91C, ASTM B80 is the definitive source. * **Unified Numbering System (UNS):** * **UNS M11910** * **Aerospace Material Specifications:** * Many proprietary internal specifications from aerospace manufacturers (e.g., Boeing BACS, etc.) may reference AZ91C for specific, legacy components. **6. Product Applications** AZ91C-T6 is used in applications requiring a robust, lightweight casting with good structural integrity. Its use is often in legacy systems or environments where its corrosion performance is deemed sufficient. * **Aerospace (Legacy Systems):** * Gearbox housings and transmission cases. * Aircraft canopy frames and actuator support brackets. * Internal airframe components and accessory mounts. * **Defense:** * Housings for portable electronic equipment and communication devices. * Components for ground support equipment. * **Industrial & Commercial:** * Housing for power tools (e.g., drills, saws) and industrial machinery. * Parts for textile and printing machines. * Brackets and frames for electronic enclosures where weight savings and EMI shielding are beneficial. **7. Handling & Considerations** * **Corrosion Protection:** For any service in humid or saline environments, a robust protective coating system is **essential**. This typically includes a chemical conversion coating (e.g., chromate or chrome-free) followed by a primer and paint. * **High-Temperature Use:** The mechanical properties of AZ91C decrease significantly at temperatures above approximately 120°C (250°F). It is not suitable for prolonged high-temperature service. * **Note on Modern Usage:** For new designs, especially those requiring superior corrosion resistance, the high-purity variant **AZ91E** is strongly recommended. AZ91E has much lower limits for Fe, Ni, and Cu, resulting in corrosion resistance an order of magnitude better than AZ91C. --- **Disclaimer:** The information provided herein is for reference purposes only. Material properties can vary based on the specific casting process, section size, and foundry. AZ91C is considered a legacy alloy in many contexts. For critical applications, consultation with a materials engineer and the component manufacturer for certified test data is essential. The use of high-purity alloy AZ91E should be evaluated for new designs.

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 3311 gallon liquid totes Special package is available on request.