Study of interfacial microstructure in hybrid additive manufactured aluminium alloys

Centre for Nanoengineering and Advanced Materials, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, South Africa

^* Corresponding author: bobmampuya@gmail.com

Abstract

Traditional manufacturing procedures have been used to make aluminium alloy engineering components for decades, but machining stages add cost and lead time. Today, the aerospace and automotive sectors use Selective Laser Melting (SLM) technologies to make near-net-shaping parts with complex geometry. This method of melting powder alloys layer-by-layer using a high-energy laser is limited to small component sizes, while traditional manufacturing processes can handle large components. A hybrid additive manufacturing (HAM)-subtractive manufacturing (SM) technology has been developed for creating complex geometry and large aluminium alloy components. The laser interacts with the powder bed on a substrate to form a molten pool that solidifies quickly when cooled during SLM. The interfacial phenomena can be directly affected by heat transfer, element dilution, diffusion, solidification dynamics, and phase transformations, which are responsible for the significant changes in the alloy’s microstructure. Optical Microscope (OM), Scanning Electron Microscopy (SEM) coupled with Electron Dispersive X-Ray Spectroscopy (EDX), X-Ray Diffraction (XRD), and microhardness were used to assess the microstructure evolution at the interface bonded zone of a cold-rolled AA 5083 and a 3D-printed AlSi₁₀Mg.