Aluminum Strontium Master Alloy

Aluminum Strontium Master Alloy is a binary master alloy with aluminum (Al) as the matrix and strontium (Sr) as the alloying element. Available in Sr5, Sr10, Sr15, and Sr20 grades with strontium contents of 5%, 10%, 15%, and 20% respectively, covering a wide range to meet different modification treatment requirements. Supplied in four forms: stick, coil, waffle ingot, and CCB — sticks and coils suit online automatic addition on continuous casting lines; waffle ingots suit manual batch addition; CCB accommodates automated feeding and flexible cutting. The recommended feed rate is 1%–2%; its core function is long-lasting modification of AlSi alloys with Si content below 13% (Modification of AlSi alloy, Si＜13%).

[Key Advantages]
· Four grades—Sr5, Sr10, Sr15, and Sr20—cover a wide strontium content range for flexible selection based on silicon content, modification requirements, and single addition amounts.
· Strontium effectively modifies eutectic silicon in Al-Si alloys, transforming coarse acicular eutectic silicon into fine fibrous or spherical silicon, fundamentally improving microstructure and significantly enhancing elongation, toughness, and fatigue performance.
· Strontium modification is long-lasting: compared to sodium modification, the effect persists longer and is retained after remelting, making it more suitable for processes requiring multiple pours or extended holding times.
· Stick and coil forms support online precise addition for consistent modification in continuous production; waffle ingot and CCB forms flexibly accommodate batch smelting and multi-variety production.
· Recommended feed rate 1%–2% allows precise control; stable composition ensures reliable and consistent modification effects.

[Product Uses]
· Core application: long-lasting modification of AlSi alloys with Si＜13%; recommended feed rate 1%–2% — widely used in hypoeutectic and eutectic Al-Si casting alloys (e.g., A356, ZL101, ADC12) smelting batching.
· In automotive aluminum castings (wheels, engine blocks, pistons), aerospace cast aluminum structural parts, and high-end electronic heat sink alloys, strontium modification significantly improves casting elongation, toughness, and fatigue life.
· In continuous casting and semi-solid casting processes, stick or coil forms enable online precise addition for uniform modifier distribution; in batch smelting, waffle ingot or CCB form is added at 1%–2% for convenient operation and stable long-lasting modification.
· Suitable for modification treatment of recycled aluminum casting alloys, replenishing strontium to restore modification effects diminished by multiple remelting cycles, improving quality consistency and mechanical properties of recycled aluminum castings.