Current status and recent advances in magnesium-matrix syntactic foams: Preparation, mechanical properties, and corrosion behavior

Over the last ten years, magnesium (Mg)-based syntactic foams (SFs) have gained significant attention and their popularity continues to grow. This is because they possess unique properties such as high mechanical strength and are lightweight, making them potential candidates for applications in various industries, including aerospace, automotive, and biomedical (especially in orthopedics). This article reviews and discusses different fabrication techniques used in producing magnesium-matrix syntactic foams (Mg-MSFs). These techniques include stir casting, disintegrated melt deposition, powder metallurgy, and melt infiltration. The review comprehensively analyzes microstructure specifications, mechanical properties, and corrosion behavior exhibited by Mg-MSFs fabricated to date. The findings suggest that the properties of these foams, including microstructural characteristics, mechanical properties, and corrosion behavior, are significantly influenced by factors such as filler particle amounts and properties, Mg alloy-matrix specifications, fabrication techniques, process parameters, and post-processing treatments (such as annealing and sintering). These factors play a crucial role in determining the final characteristics of the syntactic foams. While Mg-MSFs hold substantial importance and potential, a limited body of research exists in this area. Therefore, more research is necessary to comprehensively understand these structures, which will facilitate their effective utilization in both industrial and biomedical applications.