Aluminum (Al) Hybrid Metal Matrix Composites (HMMCs) are extensively used in aerospace, automotive and other industries, replacing the usage of single reinforced metal matrix composite material. In the last five years, due to the advancement of technology, HMMCs have witnessed largely enhanced application and usage. HMMCs exhibit robust and well-enhanced properties when compared to the single reinforced composite materials. In this review, different types of reinforcements used by the researchers are discussed. Further, the volume fraction of reinforcement and the types of fabrication method adopted are also examined. Selecting suitable process parameter for the fabrication of composite material is important, which results in equal distribution of reinforcement in the matrix material. For machining, composite material nontraditional machine was adopted by most of the researchers; especially Wire Electrical Discharge Machine (WEDM) and Electrical Discharge Machine (EDM) are widely used due to their dimensional accuracy and less distortion over the surface of the workpiece. The application of Al HMMCs, problems encountered in the machining of HMMCs and the future possible research trends in this area are also discussed.

Hybrid Metal Matrix Composites (HMMCs) are made up of two or more reinforcements that are integrated into a single matrix material to get the desirable properties (Ramesh et al., 2014a). Aluminum Metal Matrix Composites (AMMCs) are high-performance aluminum-centric material systems that refer to the class of lightweight materials. The reinforcements in AMMCs in volume fractions ranging from a few percent to 70% can be in the form of continuous/discontinuous fibers, whiskers or particulates. The properties of AMMCs can be tailored to the demands of different industrial applications by suitable combinations of the matrix, reinforcement and fabrication process (Surappa, 2003). For many researchers, the term ‘metal matrix composites’ is frequently associated with the term light Metal Matrix Composites (MMCs). Significant progress in the development of light MMCs has been attained in recent decades, hence it has been introduced in most of the automotive, aerospace and healthcare applications (Kainer, 2006).

Mechanical Engineering Journal, Aluminum (Al), Hybrid Metal Matrix Composites (HMMCs), Wire Electrical Discharge Machine (WEDM), Electrical Discharge Machine (EDM).