Each year, composites find their way into hundreds of new applications, from golf clubs and tennis rackets to jet skis, aircraft, missiles and spacecraft. Composite materials offer designers an increasing array of as a material and system solution. At the same time, composite cost trends are highly favourable, especially when the total cost of fabrication is considered. Processes such as pultrusion offer the means to convert composite materials into finished products in a single trip through the machinery. Composite sheet moulding compounds allow the formation of complete automobile skin panels in a single stroke of a press.

Advantages

Composites offer many advantages over other materials. The main advantages of composites may be summarised as: 

• Stronger and stiffer than metals on a density basis
  • For the same strength, lighter than steel by 80% and aluminium by 60%
  • Superior stiffness-to-weight ratios 
• Capable of high continuous operating temperatures
  • Up to 250°F in many composites
  • Up to 2000°F with specialist composites
• Highly corrosion resistant
  • Essentially inert in the most corrosive environments
• Electrically insulating properties are inherent in most composites (depending on reinforcement selected).
  • Yet composites can be made conducting or selectively conducting as needed.
• Tailorable thermal expansion properties
  • Can be compounded to closely match surrounding structures to minimize thermal stresses
• Tunable energy management characteristics
  • High energy absorption or high energy conductivity at designer’s choice
  • Frequency selective acoustical and electromagnetic energy passage
• Exceptional formability
  • Composites can be formed into many complex shapes during fabrication, even providing finished, styled surfaces in the process.
• Outstanding durability
  • Well-designed composites have exhibited apparent infinite life characteristics, even in extremely harsh environments
• Low investment in fabrication equipment
  • The inherent characteristics of composites typically allow production to be established for a small fraction of the cost that would be required in metallic fabrication.
• Reduced Part Counts
  • Parts that were formerly assembled out of several smaller metallic components can be fabricated into a larger single part. This reduces manufacturing and assembly labour and time.
• Corrosion Resistance
  • The non-reactive nature of many resins and reinforcements can be custom selected to resist degradation by many common materials and in corrosive environments.
  • Benefits include lower maintenance and replacement costs.
• Electromagnetic properties
  • Radar works by sending out directional radio waves (electromagnetic radiation) through the air, then listening for a reflected return from an airplane or other object. Composites are normally transparent to electromagnetic radiation, but can be “seeded” with appropriate materials to absorb such radiation and divert its energy away from the source. This low observability is called “stealth” in the popular press, and is a vitally important capability in military applications.
  • Composite materials can also be used to reduce transmitted mechanical noise from a ship or submarine to the surrounding water, thus making it more difficult to detect vessels using acoustic means.