AlSr10 (Modificador)
Strontium eutectic-silicon modifier we commercialize to transform acicular silicon into a fine fibrous structure, improving the ductility of Al-Si alloys.
AlSr10 is a modifying master alloy that delivers strontium (Sr) to the aluminum melt to modify the eutectic-silicon morphology in Al-Si alloys. Unmodified, eutectic silicon solidifies as coarse acicular plates that act as stress concentrators and reduce ductility; strontium transforms it into a fine, rounded fibrous structure, markedly improving elongation, toughness, and finish. Versus sodium (Na), strontium offers a more durable effect (lower fade) and lower hydrogen pickup. **We commercialize and distribute this master alloy; we do NOT manufacture it**, because dispersing strontium homogeneously and reproducibly at scale is highly specialized. We supply it in rod or waffle form.
International Nomenclature
| Standard | Designation |
|---|---|
| Designación | AlSr10 (Al-10Sr) |
| Formato | Varilla (rod) · waffle |
Chemical Composition
| Element | Symbol | Percentage |
|---|---|---|
| Aluminum | Al | Balance |
| Strontium | Sr | 9.0–11.0% |
| Silicon | Si | ≤0.30% |
| Iron | Fe | ≤0.30% |
| Calcium | Ca | ≤0.10% |
Physical Properties
| Property | Value |
|---|---|
| Density | ~2.65 g/cm³ |
| Form | Varilla (rod) · waffle |
| Active Element | Sr (modificador) |
Key Characteristics
- Eutectic-silicon modifier in Al-Si alloys via strontium addition
- Transforms acicular silicon into a fine fibrous structure, improving ductility
- More durable effect (lower fade) and lower hydrogen pickup than sodium (Na)
- Typical addition 0.1–0.3% (1–3 kg/t) for a residual Sr of 0.01–0.03%
- Commercialized and distributed by TP in rod and waffle form — not manufactured
Industries & Applications
Foundry
Modification of Al-Si alloys (A356, A380, etc.) for greater ductility and toughness
Automotive
Property improvement in Al-Si wheels and structural components
Aerospace
Modification of safety-critical castings
Special Notes
**TP commercializes and distributes this master alloy; it does not manufacture it.** Dispersing strontium homogeneously and reproducibly at production scale is a highly specialized process, the domain of dedicated master-alloy producers. The typical addition is 0.1–0.3% (1–3 kg per tonne of melt), leaving a residual strontium of 0.01–0.03% — sufficient for complete eutectic-silicon modification. We supply it in rod or waffle form from specialized producers, ready for controlled addition.
Frequently Asked Questions
What is AlSr10 and what is it used for?
AlSr10 is a modifying master alloy that delivers strontium (Sr) to the aluminum melt to modify the eutectic-silicon morphology in Al-Si alloys. Its purpose is to transform coarse acicular silicon into a fine fibrous structure, improving the ductility, toughness, and finish of Al-Si castings such as A356 and A380. It is used in foundry, automotive (wheels and structural components), and aerospace (safety-critical castings).
Does TP manufacture AlSr10 or only commercialize it?
TP commercializes and distributes this master alloy; it does not manufacture it. Dispersing strontium homogeneously and reproducibly at production scale is a highly specialized process, the domain of dedicated master-alloy producers. We supply it in rod or waffle form, ready for controlled addition.
What is the composition of AlSr10 and what is its active element?
The active element is strontium (Sr), present at 9.0–11.0%, with aluminum as the balance. It also contains controlled impurity levels: silicon ≤0.30%, iron ≤0.30%, and calcium ≤0.10%. Its density is approximately 2.65 g/cm³.
What AlSr10 addition rate should be used and what residual strontium does it leave?
The typical addition is 0.1–0.3% (1–3 kg per tonne of melt), which leaves a residual strontium of 0.01–0.03% — sufficient for complete eutectic-silicon modification. Supplied in rod or waffle form, it is ready for controlled addition to the aluminum melt.
Why use strontium (AlSr10) instead of sodium (Na) for modification?
Versus sodium, strontium offers a more durable effect — that is, lower fade over the melt holding time. In addition, strontium results in lower hydrogen pickup, which reduces the risk of porosity in the casting. Both factors make strontium a more stable and reproducible modifier.
How does AlSr10 improve the properties of Al-Si alloys?
Unmodified, eutectic silicon solidifies as coarse acicular plates that act as stress concentrators and reduce ductility. The strontium in AlSr10 transforms that morphology into a fine, rounded fibrous structure, which markedly improves the elongation, toughness, and finish of the part. This is why it is applied to Al-Si alloys such as A356 and A380 that require greater ductility.
Need AlSr10 (Modificador)?
We manufacture this alloy in ingots, donuts, and bars to your exact specifications.