Effect of Rare Earth Metals on the Microstructure of Al-Si Based Alloys

Materials

Saleh A. Alkahtani²  Emad M. Elgallad¹  Mahmoud M. Tash²  Agnes M. Samuel¹  Fawzy H. Samuel¹  Mark T. Whittaker³ 

[1] Département des Sciences Appliquées, Université du Québec à Chicoutimi, Chicoutimi, QC G7H 2B1, Canada;Industrial Engineering Program, Mechanical Engineering Department, College of Engineering, Prince Sattam bin AbdulAziz University, Al Kharj 11942, Saudi Arabia;;Industrial Engineering Program, Mechanical Engineering Department, College of Engineering, Prince Sattam bin AbdulAziz University, Al Kharj 11942, Saudi Arabia

关键词: aluminum alloys;    La and Ce addition;    rare earth metals;    modification;    intermetallics;   

DOI  :  10.3390/ma9010045

来源: mdpi

【 摘 要 】

The present study was performed on A356 alloy [Al-7 wt %Si 0.0.35 wt %Mg]. To that La and Ce were added individually or combined up to 1.5 wt % each. The results show that these rare earth elements affect only the alloy melting temperature with no marked change in the temperature of Al-Si eutectic precipitation. Additionally, rare earth metals have no modification effect up to 1.5 wt %. In addition, La and Ce tend to react with Sr leading to modification degradation. In order to achieve noticeable modification of eutectic Si particles, the concentration of rare earth metals should exceed 1.5 wt %, which simultaneously results in the precipitation of a fairly large volume fraction of insoluble intermetallics. The precipitation of these complex intermetallics is expected to have a negative effect on the alloy performance.

【 授权许可】

CC BY   
© 2016 by the authors; licensee MDPI, Basel, Switzerland.