Metal matrix composites (MMCs), metals, and alloys reinforced with particles, fibres, platelets, or whiskers with different physical and chemical properties are intensively studied in the last two decades. If at least one size of the reinforcing phase is in the micrometer range, we deal with the metal matrix microcomposite (mMMS) or if it exhibits a size up to 100 nm, this is a metal matrix nanocomposite (nMMC).