Strontium Modifier – Al–Sr Master Alloy (10%)
The Al–Sr Master Alloy is a concentrated alloy containing 10% Strontium (Sr) with the balance being Aluminum (Al). It is primarily supplied in rod, ingot, or waffle form for addition to molten aluminum casting alloys, particularly those containing Silicon (Si) (e.g., A356, A380).
Its essential role is as a Modifier, where it chemically changes the morphology (shape) of the brittle, acicular (needle-like) Silicon phase into a fine, fibrous, or rounded structure. This transformation dramatically improves the alloy’s ductility, fracture toughness, and machinability.
Main Function and Mechanism
Strontium is the most effective and widely used element for the long-lasting modification of the eutectic silicon phase in aluminum alloys.
| COMPONENT | CHEMICAL SYMBOL | PRIMARY FUNCTION |
|---|---|---|
| Strontium | Sr | Modifier; changes Si crystal growth; promotes fibrous structure. |
| Aluminum | Al | Carrier metal; forms the bulk of the alloy. |
| CLASSIFICATION | DELIVERY METHOD | PRIMARY APPLICATION FOCUS |
|---|---|---|
| Modifier/Refiner | Rod, Waffle Ingot | Hypoeutectic and Eutectic Al–Si casting alloys for automotive and aerospace. |
Key Performance Metrics
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
|---|---|---|
| Ductility | DRAMATICALLY IMPROVED | Eliminates sharp crack initiation points caused by needle-like Si phases. |
| Modification Longevity | HIGH | Effect persists longer than Na modifiers. |
| Machinability | IMPROVED | Rounded Si phases reduce tool wear. |
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The Modification Mechanism
In Al–Si casting alloys, the eutectic phase is composed of Aluminum and Silicon. Without modification, the Silicon precipitates as large, brittle, acicular (needle-like or plate-like) crystals.
The addition of Strontium (Sr) changes the way the Si crystals grow:
Mechanism: Strontium segregates to the Al/Si interface, poisoning the growth points of the Si crystal, suppressing plates and forcing Si to grow as fine, rounded, or fibrous particles.
Result: This modified microstructure eliminates stress concentration points, boosting alloy elongation (ductility) by 200% or more. -
Delivery and Form
Rod: The Al–Sr alloy is often cast into a continuous rod for automated feeding.
Ingots/Waffles: Used for bulk additions. -
Technical Guidance
Target Residual: The needed Sr content is 0.008% to 0.025%, based on the Si content of the alloy.
Fade Time: The Sr effect fades over time as Sr oxidizes or is lost; holding time must be monitored.
Hydrogen Control: Sr modification slightly increases susceptibility to hydrogen porosity; thorough degassing is required before Sr addition.
✨ Customization Services
We offer product customization services, allowing you to tailor the appearance, dimensions, or specific markings of items like refractory shapes or bricks. This includes options for incorporating specific geometric requirements to ensure seamless integration into your process systems.
🔬 Sampling for Testing & Validation
Free product samples are available for thorough testing and validation. This allows you to confirm the quality, compatibility, and performance of our materials—such as specific bricks, castables, or raw materials—before committing to a full order.
💡 Expertise in Refractory Solutions
Leverage our deep expertise to receive detailed, application-specific refractory solutions. We move beyond just selling products by providing comprehensive plans that encompass material selection, installation guidance, and performance optimization to maximize the lifespan and efficiency of your high-temperature processes.
Rabatec products are exclusively manufactured in facilities that have achieved rigorous ISO certifications across Quality (ISO 9001), Environmental Management, and Occupational Health & Safety. This commitment ensures every product, from refractory bricks to specialized equipment, meets the highest global benchmarks for performance, sustainability, and workplace safety.
📦 Logistics Excellence: Shipping, Packaging, and Marking
Minimizing Risk: We manage all logistics to minimize handling touchpoints and transit shock. Our carriers are pre-vetted for their experience in transporting heavy, fragile, and sensitive industrial materials.
Traceability: Every shipment includes comprehensive documentation and tracking information, providing end-to-end visibility and ensuring precise delivery coordination for your site.
Protection is Paramount: Our packaging strictly follows industry standards to prevent damage, corner chipping, and moisture absorption—especially critical for materials like Basic Refractory Bricks and Refractory Mortars & Mixes.
Robust Palletization: Products are secured on fumigated, high-strength export pallets (e.g., 1100x950mm or similar sturdy dimensions) using heavy-duty strapping and durable protective wrapping (polyethylene sheeting, cardboard, etc.) to withstand long-distance travel and multiple loadings.
Moisture Control: Sensitive materials are protected with appropriate sealing and, where necessary, desiccants or moisture-vapor proof enclosures to maintain the product's integrity until installation.
Clear Identification: All outer packaging is clearly marked on multiple sides with large, legible text for immediate identification and safe handling.
Full Traceability: Markings include all essential data points: Product Name, Quality Grade, Batch Number, Quantity, Net/Gross Weight, Order Number, and the Final Destination/Construction Area. This ensures every pallet can be accounted for and correctly staged upon arrival.
Safety & Compliance: We adhere to all regulatory requirements for marking, labeling, and placarding—especially for any items classified as Dangerous Goods—to ensure full compliance with international and domestic transport regulations.
❓ Frequently Asked Questions (FAQ)
Question | Elaborated Answer |
Q: What is the Refractoriness Under Load (RUL) of your refractories? | A: Refractoriness Under Load (RUL) is a critical property that defines the maximum temperature our materials can withstand while under compressive stress before deforming (softening). Since we offer a wide range of materials—from Alumina-Silicate Bricks to high-performance Silicon Carbide Bricks—the RUL varies significantly. For specific product data, please refer to the product data sheet or submit a quote request for the material you are interested in. |
Q: Where are the Rabatec refractories and materials produced? | A: Our products are primarily sourced from specialized manufacturing plants in China. Crucially, these facilities have all undergone rigorous audits and achieved comprehensive ISO certifications (Quality, Environment, and Safety), ensuring that production adheres to the highest global standards for consistency and performance. |
Q: What refractory materials does the company offer? | A: We supply a comprehensive portfolio of advanced refractory solutions, including: Shaped Products: Alumina & Silica Bricks, Basic & Specialized Bricks (e.g., Magnesia), SiC & Structural Ceramics, and Precast Shapes. Monolithic Products: Refractory Castables, Mixes & Mortars. Insulation: Insulation Fibre and High-Performance Insulation Products. |
Q: How should I choose the appropriate refractory material for my application? | A: Selecting the correct refractory is paramount to process efficiency. The choice depends on three key factors: 1. Operating Environment: Maximum process temperature and thermal cycling (shock). 2. Chemical Attack: Type of slag, molten metal, or corrosive gas being handled (acidic, neutral, or basic). 3. Mechanical Stress: Abrasion, erosion, and static load requirements. We recommend utilizing our detailed refractory solutions service to consult with our engineers for an optimized, application-specific recommendation. |
Q: Which monolithic material should I choose when patching an existing lining? | A: For patching and minor repairs, the ideal monolithic material depends on the parent lining material, the patching depth, and the need for a rapid return to service. Common choices include: Refractory Mortars & Mixes (for minor joints/surfaces) or Plastic Refractories (for areas requiring physical compaction). Always choose a patch material chemically compatible with the existing lining to ensure proper bonding and service life. |
Q: Can I receive product samples before placing a major order? | A: Yes. We gladly provide product samples for your internal testing and validation purposes. This ensures you can confirm the quality, composition, and fit of the material—such as our Refractory Castables or Alumina-Silicate Bricks—in your specific operational environment before committing to a bulk purchase. |
Q: Do you provide certifications to verify material quality? | A: Absolutely. We provide product-related inspection certificates and quality assurance documentation upon request. This verifies that your order has passed all internal quality control checks and meets the required material specifications and industry standards. |
Q: What measures are taken for product protection during transport? | A: We ensure quick, reliable transport by using robust, industrial packaging that strictly follows industry standards. This includes high-strength palletization, heavy-duty strapping, and weather-resistant wrapping to protect fragile items like bricks and mixes from corner chipping, mechanical damage, and moisture during transit. |
