Effects of Hollow Fly-Ash Particles on the Properties of Magnesium Matrix Syntactic Foams: A Review

In the past decade, magnesium has been seen as one of the most potential metals for weight-critical engineering applications. As magnesium is the lightest structural metal, it has higher weight-saving capabilities when compared to aluminum. Significant research efforts have been carried out on magnesium matrix alloys and composites to tailor and enhance mechanical properties based on end applications. This paper provides a review on fly-ash-reinforced magnesium matrix syntactic foams. Fly-ash cenospheres are made up of mainly alumina and silica and also contains large number of trace elements, which makes it intriguing to analyze the microstructure and interfacial responses of the end composites. In comparison with aluminum matrix syntactic foams, the research on magnesium matrix syntactic foams is still at an incipient stage. This paper provides an insight on processing techniques, microstructural and mechanical evaluations of pure Mg, AZ, and ZC alloy series, and their syntactic foams. This paper also reviews the weight-saving ability of magnesium matrix syntactic foams and their potential scope and applications.