Recycling of Al-Si alloy powder for use in additive manufacturing

• Grant number: 25/01968-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2025
• End date: May 31, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Claudio Shyinti Kiminami
• Grantee: Michelle Ramos Dalvi
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Gas atomization, widely used in the production of metallic powders due to its low cost and high productivity, generates fractions of particles that are discarded for not meeting application requirements, typically very fine particles (< 20 ¿m) or very coarse ones (> 200 ¿m). Recently, the research group on gas atomization and additive manufacturing at DEMa-UFSCar started a research project supported by CNPq and in partnership with a company that produces metallic powders. The company manufactures powders of various alloys, including an Al-Si alloy. However, a fraction of the particles of this alloy, with sizes smaller than 20 µm, is discarded for not meeting the specific requirements of clients. This discarded powder exhibits low flowability due to its reduced size and irregular shape, which is caused by its production method. Considering that this alloy is widely used and has excellent processability in additive manufacturing (AM), the reuse of this discarded material for AM processes is of great interest. In this context, this undergraduate research project aims to evaluate the feasibility of reusing discarded Al-Si alloy powder in AM processes. To achieve this, the discarded powder will be characterized in terms of morphology, flowability, density, and particle size distribution. Additionally, two methods will be assessed to enable its use: (1) blending with silica nanoparticles to improve flowability, as suggested in the literature; and (2) remelting of the powder to produce material for subsequent re-atomization, aiming to obtain particles with properties more suitable for AM. The properties of the material produced from the discarded powder will be compared to those made from the pure alloy. Ultimately, the project aims to determine the feasibility of reusing discarded powder and propose the best approach for processing it, contributing to waste reduction and minimizing the environmental impact associated with the use of metallic powders in additive manufacturing.