Composite Profiles

Nanocomposites
Nanocomposites are both man-made and naturally occurring. The reinforcer is generally a nanomaterial such as carbon nanotubes or graphene added to a polymer matrix, or silicon nanoparticles added to steel to induce fine crystal growth. In some applications, calcium carbonate or talc can also be effective in making polymers stiffer and stronger.

Metal Matrix Composites (MMCs)
MMCs use a metal matrix like aluminum or magnesium and a high-strength fiber reinforcer in particle or whisker form. Reinforcers are generally carbon fiber or silicon carbide particles. This develops unique properties that go beyond the basic metal component’s limits, including increased strength and stiffness, elevated temperature resistance before the onset of weakening, improved wear resistance, and reduced coefficient of thermal expansion.

Polymer Matrix Composites (PMCs)
PMCs are the most prevalent and easily understood forms of composite materials. This term encompasses the hand lay-up of carbon fiber and glass fiber fabrics and the manual, injected, or pre-impregnated epoxies and polyester resins that form the matrix. These materials offer various benefits including high stiffness and strength (compared with the part weight), great thermal, chemical, and mechanical resilience, and abrasion resistance. On the other hand, PMC requires highly skilled labor, resulting in higher costs, though these are often not excessive for applications that need a high-strength outcome.

Glass Fiber Reinforced Polymers (GFRPs)
GFRPs are a subset of polymer matrix composites, specific to epoxy and polyester bonded glass fiber materials. The glass fiber can be in chopped strands, lending a degree of anisotropic strength to structures by the mixed orientation of the fibers. The reinforcer can also comprise chopped strand roving (or fabric), making a more orderly process but less well suited to bulk components as fibers are all laid in one plane. Woven roving improves the quality of lay-up and can offer greater strength, at a price.

Hybrid Composites
Hybrid composites are those in which two or more different reinforcing fibers are integrated into the final material. This could be a combination of glass and carbon fiber in a lay-up—for enhanced impact resistance or cosmetic reasons. It is common to use titanium mesh or strands in the manufacture of racquets for ball sports, to improve tensile and bending performance. These materials can be challenging, as compatibility issues can affect the behavior of the material—for example, one fiber may bond better to the matrix than the other. Considerable testing is required to confirm the value or feasibility of the hybrid matrix. They have the same applications as PMCs, but the higher cost restricts their use.

Ceramic Matrix Composites (CMCs)
CMCs consist of a ceramic matrix and reinforcing fibers. A ceramic matrix provides extreme temperature and corrosion resistance and excellent wear properties. But ceramics are generally brittle when unreinforced. The addition of silicon carbide, alumina, or carbon fibers can counter the brittleness to make a more serviceable material.