AZ92A (AMS 4395) Magnesium Alloy,E FOUR

### **AZ92A Magnesium Alloy (AMS 4395)** **Product Overview** AZ92A is a high-strength magnesium-aluminum-zinc casting alloy that represents one of the strongest commercially available magnesium alloys in the standard Mg-Al-Zn system. As specified in AMS 4395, this alloy offers superior mechanical properties, excellent castability, and good corrosion resistance, making it particularly suitable for aerospace and defense applications where high strength-to-weight ratio and structural reliability are paramount. The alloy's optimized aluminum and zinc content provides enhanced strength characteristics through the formation of stable intermetallic phases. This alloy is typically supplied as sand castings, permanent mold castings, and investment castings, with properties that can be further enhanced through T4 (solution heat treated), T5 (artificially aged), or T6 (solution heat treated and aged) heat treatments. --- #### **1. Chemical Composition** AZ92A features an enhanced aluminum-zinc composition for maximum strength in cast components. | Element | Composition (% by Weight) | | :---------------- | :-------------------------------- | | **Aluminum (Al)** | 8.5 - 9.5 % | | **Zinc (Zn)** | 1.6 - 2.4 % | | **Manganese (Mn)** | 0.10 - 0.30 % | | **Silicon (Si)** | ≤ 0.20 % | | **Copper (Cu)** | ≤ 0.05 % | | **Iron (Fe)** | ≤ 0.005 % | | **Nickel (Ni)** | ≤ 0.002 % | | **Other Impurities** | ≤ 0.02 % (each) | | **Magnesium (Mg)** | Balance | *Note:* The higher **aluminum** content compared to AZ91 increases the volume fraction of the hard Mg₁₇Al₁₂ intermetallic phase, resulting in improved strength and hardness. The elevated **zinc** content provides additional solid solution strengthening, while strict limits on **iron**, **copper**, and **nickel** ensure good corrosion resistance. --- #### **2. Physical & Mechanical Properties** AZ92A exhibits the highest strength and hardness among standard Mg-Al-Zn casting alloys. **Physical Properties:** * **Density:** 1.82 g/cm³ (0.066 lb/in³) * **Melting Range:** 470 - 595 °C (878 - 1103 °F) * **Coefficient of Thermal Expansion:** 26.2 μm/m·°C (20-200°C) * **Thermal Conductivity:** 54 W/m·K * **Specific Heat Capacity:** 1050 J/kg·K **Typical Mechanical Properties (As-Cast):** * **Ultimate Tensile Strength (UTS):** 230 - 280 MPa (33 - 41 ksi) * **Tensile Yield Strength (TYS):** 150 - 180 MPa (22 - 26 ksi) * **Elongation:** 1 - 3% * **Compressive Yield Strength:** 150 - 180 MPa (22 - 26 ksi) * **Shear Strength:** 140 - 160 MPa (20 - 23 ksi) * **Fatigue Strength:** 110 - 130 MPa (16 - 19 ksi) * **Hardness:** 75 - 85 HBW * **Modulus of Elasticity:** 45 GPa (6.5 × 10³ ksi) **Elevated Temperature Performance:** * **Maintains strength up to approximately 120°C (248°F)** * **Good wear resistance at room temperature** * **Limited creep resistance above 120°C** * **Gradual strength reduction above 150°C** --- #### **3. International Standards & Specifications** AZ92A is recognized by several major international standards organizations. * **Aerospace Material Specification:** **AMS 4395** (Primary governing specification) * **ASTM International:** **ASTM B80** (Standard Specification for Magnesium-Alloy Sand Castings) * **ASTM International:** **ASTM B93** (Standard Specification for Magnesium-Alloy Die Castings) * **SAE International:** **SAE J465** * **UNS Designation:** **UNS M11920** * **Federal Standard:** **QQ-M-56** * **ISO Standards:** **ISO 16220** --- #### **4. Product Applications** AZ92A is primarily used in applications requiring the highest strength among standard magnesium casting alloys. * **Aerospace & Defense:** * **Aircraft Gearbox Housings** * **Engine Accessory Housings** * **Missile Components and Housings** * **Aircraft Structural Brackets** * **Helicopter Transmission Components** * **Military Applications:** * **Weapon System Components** * **Military Vehicle Parts** * **Communication Equipment Housings** * **Portable Military Equipment** * **High-Performance Automotive:** * **Racing Transmission Cases** * **High-Performance Engine Components** * **Competition Vehicle Structural Parts** * **Specialty Bracket and Mounting Systems** * **Industrial Applications:** * **High-Stress Machinery Components** * **Power Tool Housings** * **Material Handling Equipment** * **Specialized Industrial Machinery Parts** --- #### **5. Manufacturing Characteristics** **Casting Performance:** * Good castability with adequate fluidity * Higher tendency for microporosity compared to lower aluminum alloys * Suitable for both sand and permanent mold casting * Requires proper gating and risering design * Good dimensional stability **Secondary Processing:** * Good machinability, though harder than AZ91 * Produces good surface finish * Responsive to heat treatment (T4, T5, T6) * Good response to surface treatments and coatings * Weldable with proper procedures --- **Summary** **AZ92A Magnesium Alloy (AMS 4395)** represents the high-strength variant in the Mg-Al-Zn alloy system, offering superior mechanical properties for demanding aerospace and defense applications. The enhanced **aluminum and zinc content** provides maximum strength and hardness characteristics through increased volume of strengthening phases, making it suitable for applications where mechanical loading is the primary design consideration. While the alloy exhibits reduced ductility compared to lower-aluminum alloys, its compliance with **AMS 4395** ensures reliable performance in critical aerospace components. AZ92A continues to serve important roles in aircraft, missile, and high-performance applications where its exceptional strength-to-weight ratio and proven reliability provide significant advantages over other materials. The alloy's certification to aerospace standards makes it a trusted choice for engineers designing weight-critical structural components that must withstand demanding service conditions.

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 3437 gallon liquid totes Special package is available on request.