Aluminium-silicon Master Alloy，Aluminium silicon Alloy，AlSi Alloy，E FORU

**Product Datasheet: Aluminium-Silicon Master Alloy (Al-Si Alloy)** **Version:** 1.0 | **Date:** 2025-04-02 --- ### **1. General Overview** Aluminium-Silicon Master Alloy (Al-Si Alloy) is the most fundamental and widely used master alloy system in the aluminium casting industry. Silicon significantly improves casting characteristics, fluidity, and hot tear resistance while reducing shrinkage porosity. This master alloy forms the basis for the extensively used 4xxx series alloys and is essential for producing hypoeutectic, eutectic, and hypereutectic aluminium-silicon casting alloys with optimized mechanical properties and manufacturing characteristics. --- ### **2. International Standards** Al-Si master alloys are governed by numerous international standards: - **ASTM:** ASTM B179 (Standard Specification for Aluminum Alloys in Ingot and Molten Forms) - **ISO:** ISO 209-1 (Wrought aluminium and aluminium alloys) - **EN:** EN 1676 (Aluminium and aluminium alloys - Master alloys) - **AA:** Aluminum Association designations for 4xxx series alloys - **JIS:** JIS H 2118 (Aluminium alloy master alloys) - **GB/T:** GB/T 8734 (Aluminium alloy master alloys) - **Typical Master Alloy Grades:** Al-10%Si, Al-12%Si, Al-20%Si, Al-30%Si, Al-50%Si --- ### **3. Chemical Composition (Weight %)** Typical composition ranges for Al-Si master alloy: | Element | Content (%) | Role & Remarks | |---------------------|-------------------|------------------------------------------| | Silicon (Si) | 5.0 – 50.0 | Primary alloying element | | Iron (Fe) | ≤ 0.40 | Controlled impurity | | Copper (Cu) | ≤ 0.10 | Impurity control | | Manganese (Mn) | ≤ 0.10 | Impurity control | | Magnesium (Mg) | 0 – 1.0 | Optional addition for heat treatment | | Titanium (Ti) | 0 – 0.20 | Optional grain refiner | | Other Impurities | ≤ 0.20 total | — | | Aluminium (Al) | Balance | Base metal | --- ### **4. Physical Properties** | Property | Value / Range | |---------------------------|-----------------------------------| | Density | 2.55 – 2.70 g/cm³ | | Melting Range | 577 – 660°C (Eutectic at 577°C) | | Eutectic Composition | 12.6% Si | | Thermal Conductivity | 120 – 180 W/m·K | | Electrical Conductivity | 35 – 55 % IACS | | Vickers Hardness | 40 – 100 HV | | Coefficient of Thermal Expansion | 19–23 × 10⁻⁶/K | --- ### **5. Key Characteristics & Advantages** - **Excellent Castability:** Superior fluidity and mold filling characteristics - **Reduced Hot Tearing:** Minimizes casting defects in complex geometries - **Good Corrosion Resistance:** Excellent resistance to various environments - **Machinability:** Good machining characteristics, particularly in modified conditions - **Wear Resistance:** Hard silicon particles provide enhanced abrasion resistance - **Pressure Tightness:** Reduced shrinkage porosity for pressure-tight castings --- ### **6. Product Applications** - **Engine Components:** Cylinder heads, engine blocks, pistons - **Architectural Castings:** Decorative elements, structural components - **Automotive Parts:** Transmission cases, brake components, wheels - **Electrical Rotors:** Rotor castings for electric motors - **Marine Applications:** Pump housings, marine hardware - **Consumer Goods:** Cookware, furniture components, machinery parts - **Aerospace:** Non-structural aircraft components --- ### **7. Available Forms** - **Master Alloy:** Ingots, notch bars, waffle plates - **Wrought Products:** Sheet, plate, wire (for brazing alloys) - **Special Forms:** Powder, granules for specific applications - **Standard Sizes:** 5–25 kg ingots --- ### **8. Technical Guidelines for Use** - **Addition Rate:** 2.0–12.0% Si to the melt (depending on target alloy) - **Melt Temperature:** 700–750°C - **Holding Time:** 20–40 minutes for homogenization - **Stirring:** Moderate mechanical stirring recommended - **Modification:** Sodium, strontium, or antimony additions for eutectic modification - **Grain Refinement:** Titanium-boron additions for grain size control --- ### **9. Classification by Silicon Content** | Alloy Type | Si Content (%) | Key Characteristics | Typical Applications | |------------|----------------|-------------------|---------------------| | **Hypoeutectic** | 5–10 | Good strength, ductility | General engineering castings | | **Eutectic** | 11–13 | Excellent castability | Automotive components | | **Hypereutectic** | 14–20 | High wear resistance | Engine blocks, pistons | | **High Silicon** | 21–50 | Low thermal expansion | Electronic packaging | --- ### **10. Mechanical Properties by Silicon Content** | Si Content (%) | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Typical Alloy | |----------------|---------------------|---------------------|----------------|---------------| | **5–7** | 160–220 | 100–140 | 8–15 | 356.0 | | **7–9** | 180–240 | 120–160 | 6–12 | A356.0 | | **9–12** | 200–260 | 140–180 | 4–10 | 413.0 | | **12–18** | 220–280 | 160–200 | 2–6 | 390.0 | --- ### **11. Modification and Refinement** | Modification Type | Addition Element | Effect on Microstructure | Resulting Properties | |-------------------|-----------------|--------------------------|---------------------| | **Eutectic Modification** | Sr, Na, Sb | Fibrous silicon instead of acicular | Improved ductility | | **Grain Refinement** | Ti, B | Fine equiaxed grains | Enhanced strength | | **Phosphorus Addition** | P | Refined primary silicon | Improved wear resistance | --- ### **12. Quality Control Parameters** - Silicon content consistency (±0.3%) - Controlled iron content and intermetallic formation - Hydrogen content < 0.15 ml/100g - Modification efficiency verification - Mechanical properties certification --- ### **13. Health, Safety & Handling** - **Standard Handling:** Generally safe with standard precautions - **Dust Control:** Silicon dust may require respiratory protection - **Personal Protection:** Standard foundry PPE required - **Ventilation:** Adequate fume extraction recommended - **Storage:** Dry conditions to prevent moisture absorption - **Disposal:** Follow standard metal disposal protocols --- ### **14. Economic & Supply Considerations** - **Cost-Effective:** Silicon is abundant and inexpensive - **Supply Security:** Excellent global availability - **Processing Efficiency:** High recovery rates in alloying - **Recycling:** Excellent recyclability with established collection systems --- ### **15. Research & Development Trends** - **High-Purity Alloys:** Development of low-iron variants for special applications - **Nanocomposites:** Al-Si composites with enhanced properties - **Additive Manufacturing:** Optimized powders for 3D printing applications - **Eco-friendly Modification:** Development of environmentally friendly modifiers - **Hypereutectic Alloys:** Improved primary silicon control for wear applications --- ### **Disclaimer** This information is provided for technical reference only. Properties and performance may vary based on specific application conditions, processing parameters, modification treatments, and heat treatment practices. The optimal silicon content and modification approach should be determined for each specific application. Users are advised to conduct thorough testing to verify suitability for their intended use. Always follow good foundry practices and safety guidelines, particularly when using modification treatments that may involve reactive elements.

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 2309 gallon liquid totes Special package is available on request.