Magnesium AZ91C-T4, Cast,E FOUR

Product Datasheet: Magnesium Alloy AZ91C-T4 (Cast), UNS M11910** **1. Overview** Magnesium Alloy AZ91C-T4 is a cast magnesium-aluminum-zinc alloy supplied in the solution heat-treated condition. The **"T4"** temper designation indicates that the castings have undergone **Solution Heat Treatment followed by natural aging** at room temperature. This process involves heating the cast components to an elevated temperature to dissolve the alloying elements into the solid solution of the magnesium matrix, then rapidly quenching to retain this supersaturated state. While newer high-purity variants like AZ91E have largely superseded AZ91C for critical applications requiring maximum corrosion resistance, AZ91C-T4 remains relevant for specific applications where its combination of mechanical properties and castability is advantageous. **2. Key Advantages** * **Enhanced Ductility and Toughness:** The T4 treatment significantly improves elongation and impact resistance compared to the as-cast (F) condition * **Good Strength-to-Weight Ratio:** Provides favorable specific strength while being approximately 35% lighter than aluminum * **Excellent Castability:** Demonstrates superior fluidity for producing complex sand and permanent mold castings * **Stress Relief:** The solution heat treatment effectively relieves internal casting stresses * **Good Machinability:** Can be machined at high speeds with excellent surface finish **3. Chemical Composition (Weight % per ASTM B80)** | 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 (Fe, Ni, Cu), which may affect corrosion resistance in aggressive environments.* **4. Physical & Mechanical Properties (Typical for Sand Cast T4 Temper)** | 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** | 240 - 275 MPa | 35 - 40 ksi | | **Tensile Yield Strength (0.2%)** | 110 - 140 MPa | 16 - 20 ksi | | **Elongation (in 50mm)** | 8 - 12 % | 8 - 12 % | | **Compressive Yield Strength** | 110 - 140 MPa | 16 - 20 ksi | | **Hardness (Brinell)** | 55 - 65 HB | 55 - 65 HB | | **Modulus of Elasticity** | 45 GPa | 6.5 × 10⁶ psi | | **Fatigue Strength** | 85 - 100 MPa | 12.3 - 14.5 ksi | **5. International Standards** * **ASTM International:** * **ASTM B80:** Standard Specification for Magnesium-Alloy Sand Castings * **SAE International:** * **SAE AMS 4435:** Magnesium Alloy Sand Castings 9Al-0.7Zn (AZ91) * **Unified Numbering System (UNS):** * **UNS M11910** * **ISO Standards:** * **ISO 16220:** Magnesium and magnesium alloys - Cast products **6. Product Applications** AZ91C-T4 is utilized in applications requiring improved ductility and toughness over the as-cast condition: * **Aerospace Components:** * Non-critical structural brackets and supports * Instrument housings and covers * Interior cabin components * **Automotive Parts:** * Transmission cases and housings * Engine accessory brackets * Intake manifolds * **Industrial Equipment:** * Power tool housings * Machinery components subject to vibration * Material handling equipment parts **7. Technical Considerations** * **Heat Treatment Cycle:** Typical T4 treatment involves solutionizing at 410-425°C (770-795°F) for 10-24 hours followed by rapid quenching in hot water or air * **Corrosion Performance:** Requires protective coatings for service in corrosive environments due to higher impurity content * **Aging Characteristics:** Naturally ages at room temperature following solution treatment * **Weldability:** Generally not recommended due to hot cracking susceptibility in heat-affected zone **8. Comparison with Other Tempers** * **vs. F (As-Cast):** T4 provides significantly improved ductility and impact strength * **vs. T6 (Aged):** T4 offers better ductility but lower yield strength and hardness * **vs. AZ91E:** AZ91C has similar mechanical properties but inferior corrosion resistance --- **Disclaimer:** This information is for reference purposes only. Properties may vary based on casting method, section size, and foundry practices. AZ91C is considered a legacy alloy; for new designs requiring optimal corrosion resistance, specify high-purity AZ91E. Always consult certified test data for critical 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 3312 gallon liquid totes Special package is available on request.