Modification of Si morphology in the microstructure of recycled Al alloys by spray forming and by the Electric Resistance Sintering (ERS) process

• Grant number: 25/06084-9
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: August 19, 2025
• End date: December 17, 2025
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Lucas Barcelos Otani
• Grantee: Vanessa Beatriz de Abreu
• Supervisor: Vicente Amigo Borras
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Universitat Politécnica de Valéncia (UPV), Spain
• Associated to the scholarship: 23/13975-1 - Modification of Si morphology in the microstructure of recycled Al alloys by spray forming, BP.IC

Abstract

Aluminum alloys intended for casting applications primarily use silicon as the main alloying element, which is the main responsible for increasing the fluidity of the liquid. The elements present in casting alloys play an important role in the behavior of the material, and it is also possible to add Cu, Mg, Mn and Zn. In this project, copper is used as one of the main alloying elements, which allows the alloy to undergo solution and precipitation heat treatment, thereby enhancing the mechanical properties of the material. The manganese is responsible for assisting in the modification of the iron-rich intermetallic phase, minimizing the formation of the beta phase in favor of the alpha phase, which exhibits a less detrimental morphology. The spray forming technique performed in the original project enabled the fabrication of two hypoeutectic Al-Si alloys contaminated with Fe, with different silicon contents. In one of the alloys, Fe-P was added to evaluate its effect on the microstructure of the alloys processed by spray forming. The main idea was to compare the changes in the morphology of the presented phases (specially the Si particles) with the addition of Fe-P. From the results, it was observed that the silicon particles were smaller and more evenly distributed in the system with P addition. From the spray forming technique, overspray powder is produced as a result of the atomization process. The objective of this research internship abroad project is to observe whether the microstructural refinement will be maintained under a different advanced processing conditions using the overspray powder as feedstock. For this purpose, the Electric Resistance Sintering (ERS) method has been proposed. This route will be used to process the samples using the recycled powder from the spray forming technique, focusing on observing the morphology of silicon particles and the porosity. In this project, the processing parameters will be studied and defined one that maximize the properties. Mechanical testing and nanoindentation testing will be carried out for the most promising conditions.