What Is The Optimal Combination Of Magnesium And Strontium Inoculant Levels To Achieve A Balance Between Eutectic Silicon Refinement And Suppression Of Β-Al5FeSi Growth In A High-pressure Die-cast A380 Aluminum Alloy, While Minimizing Porosity Defects And Ensuring A Tensile Strength Of At Least 300 MPa?

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The optimal combination of magnesium (Mg) and strontium (Sr) inoculant levels in a high-pressure die-cast A380 aluminum alloy to achieve a balance between eutectic silicon refinement, suppression of β-Al5FeSi growth, minimal porosity, and a tensile strength of at least 300 MPa is as follows:

  • Magnesium (Mg): 0.3-0.4 wt.%
  • Strontium (Sr): 0.015-0.025 wt.%

This range ensures:

  1. Eutectic Silicon Refinement: Strontium effectively modifies the silicon structure into a fine fibrous form, enhancing mechanical properties.
  2. Suppression of β-Al5FeSi: Keeping Mg at a moderate level minimizes the formation of harmful iron-rich intermetallics.
  3. Minimal Porosity: The levels of Mg and Sr are balanced to avoid excessive oxidation or surface tension issues that could lead to porosity.
  4. Tensile Strength: The combination ensures the alloy meets the required strength of at least 300 MPa by optimizing the microstructure.

Adjustments within these ranges may be necessary based on specific casting conditions and testing results.