# A New Method to Lightweight Magnesium Using Syntactic Composite Core
## 1 Introduction  
The interest in lightweight materials in the aviation and car businesses has prompted broad, innovative work endeavors to further develop lightweight matrix composites using cost-effective fabrication techniques [1]. A reduction in weight would reduce the inertia of vehicles and aircraft, thereby reducing fuel consumption and subsequently decrease the amount of carbon dioxide (CO\({}_{2}\)) produced [2, 3]. To reduce CO\({}_{2}\) emissions and to improve fuel and energy efficiency, the automotive/aerospace industry has focused on reducing the overall weight of passenger vehicles/aircraft [4]. The weight of the vehicle body can be reduced by introducing lightweight materials. This research addresses the exploration of the relationship between the product and the production system when exploring novel materials. New automotive innovations are constantly being introduced to improve a vehicle's crash safety, drivability, and fuel economy, subsequently resulting in lower overall costs [4, 5]. While cars in the past were made up of entirely steel-based products and subsequently of aluminum alloys, manufacturers are now transitioning towards magnesium and their composites that have the potential to deliver enhanced performance [4, 5]. To accommodate these new materials, new manufacturing techniques must be introduced and optimized. In terms of manufacturing technique, disintegrated melt deposition is a viable option which uses a protective argon atmosphere instead of greenhouse gases like SF\({}_{6}\) and CO\({}_{2}\), which are expensive and also harmfulto the environment [1; 6]. The feasibility of these new materials depends on several factors such as the added performance, raw material costs, and the manufacturing process, amongst others. In this context, the automotive industry is increasingly interested in smart material formulations, which enable lightweight construction. Magnesium (Mg) is the lightest structural metal and is a popular material choice when it comes to weight-critical structural components, due to its low density and high strength to weight ratio [5; 7]. This quality is especially useful for weight-critical uses in the aerospace, space, sports, and automotive industries [5]. The aerospace and automotive materials market is dominated by Al-based alloys and composites and merely replacing Al with suitable Mg materials can drastically reduce the fuel costs in transportation sectors, making it financially viable. Mg is about 33% lighter than Al, and both have similar strengths and melting points [8]. However, due to its hexagonal closed packed (HCP) structure, Mg is less ductile compared to Al, which has a face-centered cubic (FCC) structure [9; 10; 11]. While the ductility and strength of Mg can be increased by traditional alloying [12], the use of discontinuous reinforcement has improved many properties of Mg even beyond the limits of alloying [10; 13; 14; 15]. Magnesium alloys have benefits of low density, high specific strength, and good castability, but the main drawbacks are low ductility and creep resistance [3; 16]. With the ban on Mg-based materials lifted by the Federal Aviation Administration (FAA) in 2015, there is a renewed interest in developing high-performance magnesium materials for aerospace sectors [17]. In most cases, one single light metal material does not satisfy all the requirements of delivering high performance at a minimum cost [18; 19]. Therefore, a significant concern in the manufacturing sector is the current production of advanced Mg-based hybrid composite materials, as they possess an excellent potential for commercial applications.