A metal matrix composite (MMC) it is a composite material with at least two constituent parts,one being a metal necessarily,at least one of which is a metal alloy, while the other(s) may be a ceramic or organic compound. Aluminum, magnesium, and titanium are frequently chosen as the alloy component in products developed for lightweight applications.

These composites have many applications in the transportation, small engines, aerospace,computer industries,and so on.For example, MMCs are increasingly found in the automotive industry. These lightweight alloys use a metal such as aluminum as the matrix, and reinforce it with fibers such as silicon carbide. The space era has increased the demand for MMCs that possess high specific stiffness and near-zero coefficient of thermal expansion (CTE).

The following is the main benefits of using MMCs,

· Fire resistant

· Operate in wider range of temperatures

· Do not absorb moisture

· Better electrical and thermal conductivity

· Resistant to radiation damage

· Do not display outgassing

· Low Coefficient of thermal expansion and lightweight

· Good damping and high compression strength

· High specific stiffness and strength.