**1. Introduction**

In recent decades, the modern world focuses on the research of lightweight metallic materials with high strength for potential applications [1]. Over the past few years, different steel materials and its alloys have been used for the applications such as household constructions and automotive manufacturing industries due to its high strength properties. Even though steel alloys have high strength, many of the light metal alloys systems also have sufficient strength to make sure of their usage in particular applications [2].

Aluminum and magnesium alloys are widely used in industries due to low mass density in recent days. The higher strength to mass ratio makes them as most attractive materials where reducing weight is one of the most significant importance, such as electronic frame production, sports goods, spacecraft machinery production, and ground transports [2]. Even the manufacturing industries using a different kind of light metals with strategic significance are also using magnesium due to its lowest density of 1.74 g/cm3 . The magnesium density is two-third of aluminum, one-fourth of zinc, and one-fifth of steel. Among the magnesium alloys, the AZ series are widely used because of their superior properties such as excellent

castability, damping capacity, and higher machinability. In general, the magnesium alloys have low corrosion resistance and low mechanical strength, especially at elevated temperatures [3]. The necessity of lightweight materials for use in challenging applications has spurred widespread efforts to develop magnesium- metal matrix composites and cost-effective fabrication technologies. So, our research team focused on the metal matrix composites system to reach unattainable properties by the single material system.

Apart from several applications, magnesium and its alloys are considered as one of the prominence energy storage materials which can store hydrogen gas in the form of magnesium hydride [4]. Magnesium has a maximum storage capability of 7.6 wt.% as theoretical with excellent thermodynamic reversibility among the current storage materials. However, the processing temperature (300 °C) of magnesium hydrides is too high to reach the target of the department of energy of the united states of America. These poor properties and other issues have limited their commercial implementations that need to be optimized [5].

Magnesium alloys with different additive materials are quite attractive content for scientific investigations. The prepared materials' performance depends on the composition, fabrication methodology, processing techniques, and properties will be varying with materials that added to the magnesium [6]. To improve the material properties, several types of additives such as SiC, Al2O3, carbon allotropes, B4C, TiC, and transition metals (particles/whiskers) have been fabricated using liquid state technique (stir casting, squeeze casting, centrifugal casting) and semi-solidstate techniques (chemical vapor deposition and physical vapor deposition) to attain the superior properties for various applications [7–10]. The above-mentioned techniques are selected depending upon what kind of reinforcement distribution is required in matrix and how much cost can be effective. The secondary processing technique (heat treatment and plastic deformations) influences composites' micro-structures and specific behaviors and alloy materials. The secondary processing techniques are used to refine the microstructure to enhance the ductility and strength of the composites.

By investigating these materials, the characteristics of recrystallization in the magnesium and phase transformations could be recognized towards the applications [11, 12]. We are hopeful that our research studies on magnesium with different additive materials contribute the breakthrough knowledge in the field of mechanical behaviors and energy storage technology, which are viable to future applications.
