Magnesium alloys are widely employed in various applications due to their high strength-to-weight ratio and superior mechanical properties as compared to unalloyed Magnesium. Alloying is considered an important way to enhance the strength of the metal matrix composite but it significantly influences the damping property of pure magnesium, while controlling the rate of corrosion for Mg-based material remains critical in the biological environment. Therefore, it is essential to reinforce the magnesium alloy with a suitable alloying element that improves the mechanical characteristics and resistance to corrosion of Mg-based material. Biocompatibility, biodegradability, lower stress shielding effect, bio-activeness, and non-toxicity are the important parameters for biomedical applications other than mechanical and corrosion properties. The development of various surface modifications is also considered a suitable approach to control the degradation rate of Mg-based materials, making lightweight Mg-based materials highly suitable for biomedical implants. This review article discusses the various binary and ternary Mg alloys, which are mostly composed of Al, Ca, Zn, Mn, and rare earth (RE) elements as well as various non-toxic elements which are Si, Bi, Ag, Ca, Zr, Zn, Mn, Sr, Li, Sn, etc. The effects of these alloying elements on the microstructure, the mechanical characteristics, and the corrosion properties of Mg-based materials were analyzed. The mechanical and corrosion behavior of Mg-based materials depends upon the percentage of elements and the number of alloying elements used in Mg. The outcomes suggested that ZEK100, WE43, and EW62 (Mg-6% Nd-2% Y-0.5% Zr) alloys are effectively used for biomedical applications, having preferable biodegradable, biocompatible, bioactive implant materials with a lower corrosion rate.

This review article focuses on the aluminum-based metal matrix composites (Al-based MMCs). Studies or investigations of their mechanical and tribological properties performed by researchers worldwide in the past are presented in detail. The processing techniques and applications for Al-based MMCs are also documented here. A brief background on the composite materials, their constituents, and their classification, as well as the different matrix materials and particulates used in Al-based MMCs, can be found in this review. Then, an overview of dual-particle-size reinforced composites, heat treatment of Al alloys, and temper designations used in heat treatment are also included. In addition, the factors influencing the mechanical and wear properties of Al-based MMCs are discussed. The primary objective is that both present and future researchers and investigators will be assisted by the comprehensive knowledge compiled in this article to further explore and work towards the betterment of society in general.

Properties such as superior specific strength, being imponderous, and the ability to reprocess are the key features that have drawn attention to magnesium. In the last few years, applications such as automotive, aerospace, and medical applications have been seeking light-weight equipment, and light-weight materials are required for making them. These demands were matched by developing metal matrix composites with magnesium as a base and reinforced with carbon nanotubes (CNTs), grapheme nanoplatelets (GNPs), or ceramic nanoparticles. CNTs have been adopted for developing high-strength metal matrix composites (MMCs) because of their delicately superior thermal conductivity, surface-to-volume ratio, and tensile strength, but lower density. In developing high-performance light-weight magnesium-based MMCs, a small number of CNTs result in refined properties. However, making Mg-based MMCs has specific challenges, such as achieving uniform reinforcement distribution, which directly relates to the processing parameters. The composition of CNT, CNT sizes, their uniform distribution, Mg-CNT interfacial bonding, and their in-between alignment are the characteristic deciding factors of Mg-CNT MMCs. The current review article studies the modern methods to develop Mg-CNT MMCs, specifications of the developed MMCs, and their vital applications in various fields. This review focuses on sifting and summarizing the most relevant studies carried out on the methods to develop Mg-CNT metal matrix composites. The article consists of the approach to subdue the tangled situations in highlighting the Mg-CNT composites as imminent fabrication material that is applicable in aerospace, medical, and automotive fields.

Magnesium is among the lightest structural metals available, with the capacity to replace traditional alloys in mass-saving applications while still providing increased stiffness and strength. The inclusion of reinforcing components into the metallic matrix has a substantial impact on stiffness, specific strength, wear behaviour, damping behaviour, and creep properties when compared to typical engineering materials. Due to their outstanding physical and mechanical characteristics along with low density, magnesium metal matrix composites are viable materials for numerous applications. This study discusses how to choose an appropriate technique and its process parameters for synthesising magnesium-based metal matrix composites (MMCs) and gives an overview of the impacts of various reinforcements in magnesium and its alloys, emphasising their benefits and drawbacks. The essential applications of various magnesium-based MMCs are also critically examined in this article. The impact of reinforcement on the microstructure as well as mechanical characteristics are thoroughly examined.

Complex structures can now be manufactured easily utilizing AM technologies to meet the pre-requisite objectives such as reduced part numbers, greater functionality, and lightweight, among others. Polymers, metals, and ceramics are the few materials that can be used in AM technology, but metallic materials (Magnesium and Aluminum) are attracting more attention from the research and industrial point of view. Understanding the role processing parameters of laser-based additive manufacturing is critical to maximize the usage of material in forming the product geometry. LPBF (Laser powder-based fusion) method is regarded as a potent and effective additive manufacturing technique for creating intricate 3D forms/parts with high levels of precision and reproducibility together with acceptable metallurgical characteristics. While dealing with LBPF, some degree of porosity is acceptable because it is unavoidable; hot ripping and cracking must be avoided, though. The necessary manufacturing of pre-alloyed powder and ductility remains to be the primary concern while dealing with a laser-based additive manufacturing approach. The presence of the Al-Si eutectic phase in AlSi10Mg and AlSi12 alloy attributing to excellent castability and low shrinkage, attaining the most attention in the laser-based approach. Related studies with these alloys along with precipitation hardening and heat treatment processing were discussed. The Pure Mg, Mg-Al alloy, Mg-RE alloy, and Mg-Zn alloy along with the mechanical characteristics, electrochemical durability, and biocompatibility of Mg-based material have been elaborated in the work-study. The review article also summarizes the processing parameters of the additive manufacturing powder-based approach relating to different Mg-based alloys. For future aspects, the optimization of processing parameters, composition of the alloy, and quality of powder material used will significantly improve the ductility of additively manufactured Mg alloy by the LPBF approach. Other than that, the recycling of Mg-alloy powder hasn’t been investigated yet. Meanwhile, the post-processing approach, including a homogeneous coating on the porous scaffolds, will mark the suitability in terms of future advancements in Mg and Al-based alloys.