Impact of Iron Contamination on Liquid Properties and Microstructural Evolution in AlSi20

Additive manufacturing processes enable highly flexible and scalable shaping while maintaining rapid solidification processing conditions. This combination makes additive manufacturing particularly attractive for recycling contaminated alloys, as it allows critical brittle phases to be refined and utilized as alloying elements. However, little is known about the impact of contaminants on the fluid properties of liquid metals. Herein, thermodynamic modeling and experimental methods are combined to investigate the properties of AlSi20 and its contaminated variant, (AlSi20)95Fe5. The oscillating droplet method is used to experimentally determine surface tension and analyze solidified droplets to evaluate microstructure for different cooling rates. The findings indicate that while contaminants have a minor effect on fluid properties, they significantly influence microstructural properties.