|
ablation
|
The erosion or vaporization of material from causes like abrasion and heat. Parts made from carbon-carbon composites are resistant to ablation.
|
|
advanced composite
|
A composite made from specially formulated resins and high performance fibers. Advanced composites are used for applications that require a customized mixture of resins and reinforcements to produce specific properties in the composite.
|
|
alloy
|
A metal consisting of a mix of two or more elements, one of which must be a metal. Alloys can be used to make metal matrix composites.
|
|
aluminum
|
A ductile metal used in metal matrix composites.
|
|
ambient temperature
|
The nominal temperature of the air that surrounds devices and systems. Suppliers of composite materials usually recommend a maximum ambient temperature in which the part can function.
|
|
aramid
|
An advanced composite material made from nylon. Aramid fiber reinforcements are strong and flexible.
|
|
aromatic chemical
|
A highly stable type of chemical used in thermoplastic resins. Aromatic chemicals often have a strong odor.
|
|
autoclave
|
A pressure vessel that promotes faster curing through a combination of vacuum and heat. Advanced composites often require autoclave curing.
|
|
borides
|
Boron-based compounds used to create ceramic matrices for advanced composites.
|
|
boron
|
A semi-metallic chemical element used in advanced composite reinforcements. Boron fibers are much stronger than carbon fibers or glass fibers.
|
|
brittleness
|
The measure of a material's tendency to fracture from being drawn, stretched, or formed. As the rigidity of a material increases, brittleness increases.
|
|
carbides
|
Carbon-based compounds used to create ceramic matrices for advanced composites.
|
|
carbon
|
A non-metallic chemical element used in advanced composite reinforcements and matrices. Carbon is very strong and has high resistance to heat.
|
|
carbon fiber
|
A high-strength, high-modulus reinforcement used in advanced composites. Carbon fibers may be mixed with a carbon matrix to form carbon-carbon composites.
|
|
carbon-carbon composite
|
A composite made from carbon fibers and a carbon matrix. Carbon-carbon composites have the best heat resistance of any composite material.
|
|
ceramic
|
A hard, brittle material that can withstand high temperatures and resist corrosion. Some advanced composite matrices are made from ceramic materials.
|
|
ceramic matrix composite
|
A highly specialized advanced composite often used for aerospace applications. CMCs are stiff, lightweight, and can withstand extremely high temperatures.
|
|
C-glass
|
A type of glass fiber that provides greater resistance to chemicals. A small portion of advanced composites use C-glass.
|
|
char
|
A type of material that is formed from burning plastic in a low-oxygen environment. Carbon matrices are created from the carbon-containing char of polymer-based resins such as phenolics.
|
|
continuous
|
Covering the entire dimension of a part without a break or interruption. Continuous fibers provide greater strength but are more expensive to integrate with the matrix.
|
|
copper
|
A ductile, thermally and electrically conductive metal used in metal matrix composites.
|
|
cure time
|
The amount of time it takes for the molecules in a composite to cross-link. Longer cure times increase the cost of making the composite and the possibility of something going wrong in the curing process.
|
|
degassing
|
Removing dissolved gases from a liquid. Volatile gases and trapped air must be removed from metal matrix composites through degassing.
|
|
discontinuous
|
Characterized by being chopped or cut into small pieces. In ceramic matrix composites, whiskers tend to have the best mechanical properties of the discontinuous reinforcements.
|
|
ductility
|
The ability of metal to be drawn, stretched, and deformed without breaking.
|
|
elasticity
|
The measure of a material's ability to return to its original shape after being deformed from stress.
|
|
environmental properties
|
The characteristics of a material that determine how it reacts to other phenomena in close proximity. Environmental factors that affect a material include noise, air quality, machine vibration, moisture, and temperature, among other factors.
|
|
epoxy resin
|
A tough, heat-resistant resin used in advanced composites. Boron fibers are typically applied to a tape that has been preimpregnated with epoxy resin.
|
|
ether
|
An organic compound found in polyetheretherketone.
|
|
fiber
|
A slender, thread-like reinforcing material used in composites. Fibers are larger than whiskers.
|
|
fiberglass
|
Reinforcement material made from extremely fine strands of glass. Fiberglass is the most commonly used reinforcement material in composites.
|
|
fiberglass reinforced plastics
|
A commercial composite made from fiberglass and polyester resin.
|
|
flammability
|
The characteristics of a material the determine its ability or tendency to ignite or burn when exposed to an open flame. Some advanced composite applications require materials with low flammability.
|
|
glass transition temperature
|
The point at which a rigid solid becomes pliable and can be formed, shaped, or molded. In general, a higher Tg allows for greater thermal stability and helps to prevent defects during the curing of a part.
|
|
ketone
|
An organic compound found in polyetheretherketone.
|
|
magnesium
|
A strong, lightweight metal used in metal matrix composites.
|
|
matrix
|
The material that binds together the reinforcing fibers of a composite. Advanced composites use specially formulated polymers, ceramics, and carbons as the matrix.
|
|
mechanical properties
|
The characteristics of a material that determine how it reacts when it is subjected to a force that attempts to stretch, dent, scratch, or break it.
|
|
metal
|
A naturally occurring material with high electric and thermal conductivity, luster, density, and strength. Some advanced composite matrices are made from metals and metal alloys.
|
|
metal matrix composite
|
A composite made from a metallic matrix and high-performance reinforcements. MMCs have high levels of strength, stiffness, and relatively high resistance to heat.
|
|
metalloid
|
An element that has the qualities of both a metal and a non-metal. Boron is a metalloid that shares some of the qualities of aluminum, silicon, and carbon.
|
|
modulus
|
The stiffness of a material. Carbon fiber reinforcements have a high modulus.
|
|
nickel
|
A corrosion-resistant metal used in metal matrix composites.
|
|
nitrides
|
Nitrogen-based compounds used to create ceramic matrices for advanced composites.
|
|
nylon
|
A thermoplastic polymer used to make aramid fibers for advanced composites. Nylon is strong and very flexible.
|
|
organic compound
|
A highly stable type of chemical that always contains carbon. Many polymers used in composites are organic compounds.
|
|
organic resin
|
A resin made from carbon-based materials. Phenolic resin is an example of an organic resin.
|
|
oxidation
|
A chemical reaction involving the addition of oxygen and the loss of electrons. Oxidation causes metal to rust.
|
|
oxides
|
Oxygen-based compounds used to create ceramic matrices for advanced composites.
|
|
particle
|
A very tiny piece of material used as a reinforcement in advanced composites.
|
|
phenolics
|
A group of thermoset polymers derived from phenol. Phenolics are often used to create carbon resins.
|
|
plasma environment
|
An environment of partially ionized gas. A plasma environment is extremely disruptive to electrical equipment.
|
|
polyester resin
|
The most widely used thermoset polymer in the composite industry. Fiberglass reinforced plastics are made with unsaturated polyester and fiberglass reinforcement.
|
|
polyetheretherketone
|
PEEK. An advanced thermoplastic polymer used extensively in the aerospace, automotive, and marine industries.
|
|
polymer
|
A long chain of very large molecules made up of many atoms. Polymers are used to make thermoplastic resins for composites.
|
|
polymer matrix composite
|
A composite made from a polymer resin. Polymer matrix composites are not as strong or heat-resistant as metal matrix and ceramic matrix composites.
|
|
polyphenylene sulfide
|
PPS. An advanced thermoplastic resin that can withstand relatively high temperatures. PPS is flame retardant and has good resistance to chemicals, mildew, sunlight, and abrasion.
|
|
preform
|
A tough but flexible fiberglass structure that is roughly the same shape as the final product. The powdered matrix of a CMC is made into a preform which is heated and then formed into a composite part.
|
|
prepreg
|
A ready-to-mold sheet of fiber reinforcement that has been preimpregnated with resin. A prepreg made with boron fibers is very stiff.
|
|
radiation
|
Energy emitted in the form of particles or waves. Prolonged exposure to radiation can damage composites.
|
|
reinforcement
|
The part of the composite that provides strength, stiffness, and the ability to carry a load. The reinforcement material used in advanced composites is often a high-performance fiber.
|
|
S-glass
|
A type of glass fiber that provides greater strength and can withstand higher temperatures than E-glass. Advanced composites are more likely to use S-glass.
|
|
silicon carbide
|
A chemical compound made of up carbon and silicon. Silicon carbide is used to make high-performance reinforcements and matrices for composites.
|
|
solvent
|
A substance that dissolves another substance.
|
|
space debris
|
Natural and man-made objects found beyond the earth's atmosphere. Space debris can strike and damage a space vehicle.
|
|
strength
|
The measure of a material's ability to carry a load. When selecting materials for advanced composites, manufacturers must know the strength of the material.
|
|
tensile stress
|
The internal load that a part is subjected to when pulled apart by an applied force. Carbon fiber reinforcements can withstand a high amount of tensile stress.
|
|
thermal properties
|
The characteristics of a material that determine how it reacts when it is subjected to excessive heat, or heat fluctuations over time.
|
|
thermoplastic
|
A polymer composed of molecules that are not cross-linked, or are cross-linked to a weaker degree. Thermoplastics can be melted and hardened repeatedly without changing their chemical structure.
|
|
thermoset
|
A polymer that cannot be re-melted or reformed once it has cured. Thermosets have higher rigidity and better thermal stability than thermoplastics, but they take longer to process.
|
|
titanium
|
Ti. A silvery white "space age" metal with a high strength-to-weight ratio, excellent flexibility, and exceptional corrosion resistance. Titanium can be a component of metal matrix composites and is commonly used in medical components and in aerospace applications.
|
|
toughness
|
The measure of the composite's ability to absorb mechanical forces before it breaks. Tough materials generally have some measure of elasticity.
|
|
traditional composite
|
A composite that uses a relatively consistent combination of polymer resin and fiberglass reinforcement. Traditional composites are low-cost and are processed by traditional methods.
|
|
vacuum environment
|
An environment with very low density and pressure, such as outer space. In a vacuum, heat cannot be transferred through convection.
|
|
warpage
|
The deformation of a part after molding. Parts made with polyphenylene sulfide resins are vulnerable to warpage.
|
|
wet-out
|
The condition of being completely covered, and filled, with resin. Thermoplastic resins allow for good fiber wet-out in composites.
|
|
whisker
|
A very thin, short filament. Whiskers are smaller than chopped fibers.
|