Characterization of Aluminium-based alloy starting powders morphology for the synthesis of rail components through Selective Laser Melting

Abstract

Additive manufacturing is widely acknowledged as a popular fourth-industrial revolution technology used in the production of parts attributed to its numerous advantages. Hence, Selective Laser Melting of AlSi12 alloy presents a unique advantage in producing components with high density and minimal cracks or the initiation of stress. Selective laser melting is also an excellent technique for prototyping functional components. However, the process requires multiple heating cycles because it undergoes chemical and physical changes which causes variations in the powder performance and characteristics. This may lead to powder inconsistency, reactivity, and contamination. The properties of additively manufactured parts depend on the powder morphology and granulometry thus making the powders have significant advantages over standard production materials, however, there are certain restrictions in additive manufacturing. Hence, this study explores the characterization of aluminum-based alloy starting pre-alloyed powders for the synthesis of rail components using selective laser melting technology. It investigates the morphology of starting powders for the synthesis of rail components through selective laser melting. The powders were weighed accurately by using stoichiometry to make up the desired compositions. The mixing was carried out by the tubular mixer at 49 rpm for the period of 1, 4, and 8 hours, to get a uniform distribution of the alloy constituent in a dry environment at room temperature. This study aims at determining powder fitness before fabrication to ensure consistency and part quality through powder quality control, powder process optimization, and cost reduction. Morphology and qualitative phase analysis of the starting and mixed powders will be examined by X-Ray Diffractometer (XRD), field emission scanning electron microscopy (FESEM, JSM-7600F, Jeol, Japan) equipped with an energy dispersive X-ray spectrometer (EDS). The findings provide valuable insights into optimizing the SLM process for rail component synthesis using aluminum-based prealloyed powders. This study contributes to the advancement of additive manufacturing techniques for the railway industry, and potentially for other industries as well.