Thermochemical modelling and mechanical property of the Al-7.6Si-xZr alloy

Abstract

This study utilised the gravity casting method to modify hypoeutectic Al-7.6Si alloys with Zr at varying weight percentages (0.1%, 0.2%, and 0.3%). The unmodified alloy typically consists of a needle or platelike eutectic silicon within the dendritic α-Al phase. The addition of Zr increases the liquidus temperature of the alloy and results in the formation of ZrSi and ZrSi₂ compounds, which act as nucleation sites for both the eutectic Si and α-Al grains. As a result, the needle or platelike eutectic silicon transforms into a fibrous structure with a more uniform distribution, and the α-Al phase becomes finer and globular. These microstructural changes lead to improved bulk hardness, ductility, and mechanical properties of the alloy.

KEYWORDS:

• Thermochemical modelling
• hypoeutectic Al–Si alloy
• Zrsi/ZrSi₂ compound
• microstructure modification
• mechanical properties

Acknowledgements

The authors are very thankful to Mr M. K. Das of the National Institute of Technology Durgapur, India, for his support in several phases of this investigation. They also thank the Director of the National Institute of Technology Durgapur, India, for his continuous encouragement.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Institute of Technology Durgapur, India [grant number RIG # 2].