Composite materials defined as mixtures of two (or more) components; combined physically with each other. One of these components called the reinforcing phase or the discontinuous phase while the other called the matrix or the continuous phase. The final forms of the reinforcing phase component could be particles, or flakes or fibers; while the matrix phase is a multiple; for example, polymer, metal or ceramic. There are so many practical examples of composite systems; such as a concrete
reinforced with steel or epoxy resin reinforced with graphite hit fibers and many other examples.
The classifications of the composites depending meanly on the geometry of the reinforcement: whether it is particulate, flake, or fibers (Figure 1) or could be based on the nature of matrix phase: whether it is polymer, metal or ceramic .
PMC are considered as the most popular composites, comparing with the ceramic matrix composites or metal matrix composites; due to three reasons ; its lower cost; its high strength and easy to be fabricated. Despite this fact; PMC have its own disadvantages; mainly its low application temperatures, high amounts of thermal and moisture expansion coefficients and low Young’s modulus values in some applications. There are a wide range of applications for PMC composites; It ranges from tennis racquets to the space shuttle parts and many other uses.
The well-known Metal Matrix Composites (MMC) are aluminum, magnesium and titanium composites. The ideal fibers that used for reinforcement of these composites are carbon fibers and silicon carbide (SC). MMC composites are recognized with several advantages comparing with PMC. MMC have higher Young’s modulus; higher usage temperatures; larger values of electric and thermal conductivity; and better resistances to the wear, fatigue, and deformation . The flaws of MMC comparing with PMC limited to their higher processing temperatures and higher densities. The automotive engines bodies could be manufactured from MMC; which recognized of their lighter weights. (boron/aluminum) composite tubes can be served as supporters for fuselage frame in space shuttle.
The CMC are recognized with their higher strength, higher hardness, higher application temperature, their chemical inertness, and their low densities in most high temperature applications; CMC are come first because PMC and MMC cannot
be utilized at such high temperatures . CMC are used widely
in manufacturing of cutting tools that insert within oxidizing and
very hot ambient. Figure 2 shows some applications of composite
Type of composites consists of more than one type of
filler and/or more than one type of matrix material. They
are commonly employed for modifying the properties and/
or decreasing the cost of traditional composites for example
the addition of a second type of fiber, such as glass or aramid
fibers leads to increase the toughness value of the carbon fiber
Hybridization is defined as a process of incorporating
different types of synthetic fibers in order to yield better
strength, stiffness, higher (strength/ weight) ratio and other
mechanical properties. Hybrid composites can be manufactured
from a combination of natural/synthetic fibers, natural/natural
fibers, or synthetic/synthetic fibers. This type is receiving
attention from each of researchers and the industry for structural
applications due to the impact properties of these materials. The
applications of these composite are multiple such as their using
in aerospace, automotive, and construction. Figure 3 shows
(Carbon-Kevlar) hybrid lamina used in fabrication the hybrid
composite. (Figure 3)