Aluminium-hafnium Master Alloy，Aluminium hafnium Alloy，AlHf Alloy，E FORU

**Product Datasheet: Aluminium-Hafnium Master Alloy (Al-Hf Alloy)** **Version:** 1.0 | **Date:** 2025-04-02 --- ### **1. General Overview** Aluminium-Hafnium Master Alloy (Al-Hf Alloy) is a high-performance master alloy that utilizes hafnium as a potent grain refiner and precipitation strengthener. Hafnium forms stable intermetallic compounds with aluminium, particularly Al₃Hf, which provide exceptional high-temperature stability, creep resistance, and microstructural control. This master alloy is primarily used in premium aerospace, nuclear, and high-temperature applications where performance at elevated temperatures is critical. --- ### **2. International Standards** Al-Hf master alloys are specified in several international standards: - **ASTM:** ASTM B928 (High Magnesium Aluminum-Alloy Products) - **AMS:** AMS 4459 (Aluminum-Rare Earth Alloy Sheet) - **EN:** EN 1676 (Aluminium and aluminium alloys - Master alloys) - **GB/T:** GB/T 27677 (Aluminium-rare earth master alloys) - **AECMA:** PREN 2076 (Aerospace series) - **Typical Master Alloy Grades:** Al-5%Hf, Al-10%Hf, Al-15%Hf --- ### **3. Chemical Composition (Weight %)** Typical composition ranges for Al-Hf master alloy: | Element | Content (%) | Role & Remarks | |---------------------|-------------------|------------------------------------------| | Hafnium (Hf) | 2.0 – 15.0 | Primary alloying element | | Zirconium (Zr) | 0 – 5.0 | Often co-added for enhanced performance | | Titanium (Ti) | 0 – 3.0 | Optional grain refiner | | Iron (Fe) | ≤ 0.15 | Impurity control | | Silicon (Si) | ≤ 0.10 | Impurity control | | Other Impurities | ≤ 0.08 total | — | | Aluminium (Al) | Balance | Base metal | --- ### **4. Physical Properties** | Property | Value / Range | |---------------------------|-----------------------------------| | Density | 3.0 – 4.5 g/cm³ | | Melting Range | 660 – 2230°C (Hf melts at 2230°C) | | Intermetallic Phases | Al₃Hf (primary), AlHf, AlHf₂ | | Crystal Structure | L1₂ (cubic) for Al₃Hf | | Thermal Conductivity | 80 – 130 W/m·K | | Electrical Conductivity | 30 – 45 % IACS | | Vickers Hardness | 80 – 150 HV | | Neutron Absorption Cross Section | 104 barns | --- ### **5. Key Characteristics & Advantages** - **Exceptional High-Temperature Stability:** Maintains strength up to 500°C - **Superior Creep Resistance:** Excellent resistance to deformation under load at high temperatures - **Grain Refinement:** Effective grain size control through Al₃Hf nucleation - **Nuclear Properties:** Moderate neutron absorption for nuclear applications - **Oxidation Resistance:** Enhanced high-temperature oxidation resistance - **Precipitation Strengthening:** Forms coherent Al₃Hf precipitates with high stability --- ### **6. Product Applications** - **Aerospace Turbine Components:** Blade rings, turbine disks, engine mounts - **Nuclear Reactor Components:** Control rods, structural supports in nuclear applications - **Rocket Propulsion Systems:** Nozzle components, thrust chambers - **High-Temperature Structural Parts:** Airframe components near engines - **Additive Manufacturing:** Specialty powders for high-temperature 3D printing - **Automotive Turbochargers:** High-temperature compressor components - **Chemical Processing:** Equipment for high-temperature corrosive environments --- ### **7. Available Forms** - **Master Alloy:** Ingots, notch bars, granules - **Special Forms:** Powder for additive manufacturing, custom shapes - **High-Purity Grades:** 99.95% for nuclear applications - **Standard Sizes:** 2–8 kg ingots --- ### **8. Technical Guidelines for Use** - **Addition Rate:** 0.1–2.0% Hf to the melt (typically 0.3–1.0% for optimal effects) - **Melt Temperature:** 780–850°C - **Holding Time:** 45–90 minutes for complete dissolution - **Stirring:** Vigorous mechanical stirring required - **Casting Temperature:** 720–780°C - **Heat Treatment:** Solution treatment at 530–580°C, aging at 350–450°C --- ### **9. High-Temperature Performance Comparison** | Alloy System | Max Service Temp (°C) | Creep Resistance | Cost | Applications | |--------------|----------------------|------------------|------|--------------| | **Al-Hf** | 500 | Excellent | High | Aerospace, Nuclear | | **Al-Zr** | 400 | Very Good | Medium | General high-temp | | **Al-Sc** | 350 | Good | Very High | Premium aerospace | | **Al-Ti** | 300 | Fair | Low | General purpose | --- ### **10. Metallurgical Mechanisms** - Forms coherent L1₂-structured Al₃Hf precipitates - Provides dispersion strengthening through stable intermetallics - Enhances recrystallization temperature by 150–200°C - Improves grain boundary stability at high temperatures - Creates Zener pinning effect for grain growth control --- ### **11. Quality Control Parameters** - Hafnium content consistency (±0.2%) - Low gas content (hydrogen < 0.10 ml/100g) - Homogeneous distribution of Al₃Hf particles - Controlled intermetallic particle size (50–500 nm) - Certification for nuclear applications (where required) --- ### **12. Nuclear Properties** | Property | Value | |---------------------------|---------------------------| | Thermal Neutron Cross Section | 104 barns | | Resonance Integral | 2,400 barns | | Absorption Edge | 0.115 Å | | Decay Products | Stable isotopes | --- ### **13. Health, Safety & Handling** - **Low Radioactivity:** Naturally occurring hafnium has low radioactivity - **Dust Control:** Avoid inhalation of fine particles - use respiratory protection - **Personal Protection:** Standard foundry PPE with heat protection - **High-Temperature Caution:** Special precautions for high-temperature processing - **Storage:** Dry, controlled environment - **Disposal:** Follow standard metal disposal protocols --- ### **14. Economic & Supply Considerations** - **Limited Availability:** Hafnium is always found with zirconium, separation is complex - **Cost Factors:** High cost due to difficult separation process - **Strategic Material:** Critical for defense and aerospace applications - **Recycling:** Important for cost management in premium applications - **Supply Chain:** Limited number of global suppliers --- ### **15. Research & Development Trends** - **Nanoscale Precipitates:** Optimization of Al₃Hf precipitate distribution - **Multi-element Systems:** Al-Hf-Zr, Al-Hf-Sc complex alloys - **Additive Manufacturing:** High-temperature alloys for 3D printing - **Nuclear Applications:** Advanced alloys for next-generation reactors - **Coating Technologies:** Hafnium-aluminium coatings for high-temperature protection --- ### **Disclaimer** This information is provided for technical reference only. Properties and performance may vary based on specific application conditions and processing parameters. Al-Hf alloys represent premium materials with significant cost implications. Users must conduct comprehensive testing and technical-economic evaluation before implementation. For nuclear applications, special licensing and quality assurance programs are required. Always consult with materials engineering specialists for critical high-temperature 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 2295 gallon liquid totes Special package is available on request.