Nickel 79/Aluminum 21 Alloy,Ni21AI Alloy,Nickel Aluminum Alloy,E FORU

### **Nickel-Aluminum Alloy (Ni₇₉Al₂₁) - Gamma Prime (γ') Strengthening Phase Alloy** #### **Overview** **Nickel 79/Aluminum 21 Alloy (Ni₇₉Al₂₁)** represents a specialized nickel-aluminum composition that corresponds closely to the **Ni₃Al intermetallic compound**, known as the **gamma prime (γ') phase**. This phase is the primary strengthening component in most nickel-based superalloys. Unlike bulk structural intermetallics, this specific composition is primarily utilized as a master alloy for superalloy production or as a fundamental material for studying the γ' phase's intrinsic properties. The alloy exhibits an ordered L1₂ crystal structure, providing exceptional strength retention at high temperatures while maintaining good oxidation resistance. --- #### **Chemical Composition (Atomic % / Weight %)** | Element | Atomic % | Weight % (Approx.) | | :--- | :--- | :--- | | **Nickel (Ni)** | **75-80%** | **~86-90%** | | **Aluminum (Al)** | **20-25%** | **~10-14%** | | **Trace Elements** | **< 0.1%** | **< 0.1%** | *Note: This composition may include minor additions of boron (50-500 ppm) to improve grain boundary cohesion and ductility.* --- #### **Physical & Mechanical Properties** | Property | Value / Description | | :--- | :--- | | **Density** | **7.50-7.65 g/cm³** | | **Melting Point** | **~1385-1400 °C** (2525-2552 °F) | | **Crystal Structure** | Ordered L1₂ (Cu₃Au-type) | | **Thermal Conductivity** | **20-25 W/m·K** (at room temperature) | | **Specific Heat Capacity** | 420-480 J/kg·K | | **Coefficient of Thermal Expansion** | 12.5-13.5 × 10⁻⁶/°C (20-1000°C) | | **Elastic Modulus** | 180-210 GPa | | **Vickers Hardness** | 250-350 HV | | **Yield Strength (RT)** | 500-800 MPa | | **Yield Strength (800°C)** | **400-600 MPa** (exhibits positive temperature dependence) | | **Fracture Toughness** | 15-25 MPa·m¹/² | | **Oxidation Resistance** | Good - forms protective Al₂O₃ scale | --- #### **Key Characteristics & Applications** **Key Characteristics:** 1. **Positive Temperature Strength Dependence**: Unusual property where strength increases with temperature up to ~800°C 2. **Excellent High-Temperature Stability**: Maintains ordered structure up to melting point 3. **Good Environmental Resistance**: Moderate oxidation and hot corrosion resistance 4. **Anomalous Yield Strength Behavior**: Strength peaks at intermediate temperatures 5. **Boron-Doped Ductility**: Small boron additions can dramatically improve room-temperature ductility **Typical Applications:** - **Superalloy Production**: Master alloy for introducing γ' forming elements in superalloy manufacturing - **Research Material**: Model system for studying mechanical behavior of L1₂ ordered intermetallics - **Specialized Coatings**: High-temperature protective coatings for specific applications - **Advanced Composite Materials**: Reinforcement phase in composite systems - **Model System**: Fundamental studies of deformation mechanisms in ordered intermetallics --- #### **Manufacturing & Processing** | Method | Description | Applications | | :--- | :--- | :--- | | **Vacuum Induction Melting** | Standard melting under protective atmosphere | Master alloy production | | **Powder Metallurgy** | Gas atomization and consolidation | Research materials, specialized components | | **Directional Solidification** | Controlled solidification for single crystals | Fundamental property studies | | **Rapid Solidification** | Melt spinning for fine microstructures | Advanced material forms | --- #### **International Standards & Specifications** | Category | Designation | Description | | :--- | :--- | :--- | | **Research Classification** | **Ni₃Al-type** | Academic classification for gamma prime phase | | **ASTM** | **Research Grades** | Custom specifications for research materials | | **Aerospace** | **OEM Research Codes** | Proprietary designations for development programs | | **ISO** | **Not Standardized** | No commercial ISO standard for bulk material | *Note: Ni₇₉Al₂₁ is primarily a research and master alloy material rather than a commercially standardized structural alloy. Specifications are typically defined by research institutions or superalloy manufacturers for specific development purposes.* --- #### **Summary** **Nickel 79/Aluminum 21 Alloy (Ni₇₉Al₂₁)** represents the fundamental **gamma prime (γ') phase** that serves as the cornerstone of modern nickel-based superalloy technology. While rarely used as a bulk structural material itself, its exceptional properties - particularly the anomalous positive temperature dependence of strength - make it invaluable as a master alloy component and a model system for understanding high-temperature deformation mechanisms in ordered intermetallics. The extensive research on this composition has directly contributed to the development of advanced superalloys used in today's most demanding high-temperature applications, particularly in aerospace propulsion and power generation systems.

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 3215 gallon liquid totes Special package is available on request.