What are the effects of antimony in alloys on the corrosion resistance of aluminum outdoor sculptures?

The addition of antimony to aluminum alloys can significantly influence the corrosion resistance of outdoor sculptures. Antimony acts as a grain refiner, improving the microstructure of the alloy and enhancing its mechanical properties. However, its impact on corrosion resistance is complex. While small amounts of antimony may reduce pitting and uniform corrosion by stabilizing passive oxide layers, excessive concentrations can lead to galvanic corrosion due to the formation of intermetallic compounds.

For outdoor aluminum sculptures exposed to moisture, pollutants, and temperature fluctuations, optimizing antimony content is crucial. Studies suggest that alloys with controlled antimony levels (typically below 0.1%) exhibit better long-term durability, whereas higher amounts accelerate degradation. Proper alloy formulation and protective coatings can mitigate these effects, ensuring the sculpture's aesthetic and structural integrity over time.

Understanding the balance between antimony's benefits and risks helps artists and engineers design resilient aluminum artworks for outdoor environments.