Manufacturing methods of composite materials vary widely. The key materials that are most commonly described as composites are glass, carbon, and Kevlar® fibers, bonded with resins. In the case of carbon fiber, the strands are pre-impregnated with a heat-activated polyester, vinyl ester, polyurethane, or epoxy resin (prepreg). The flexible sheets of woven fabric (roving) are laid up onto/into a mold and put under pressure. They are then heated to activate the resin which first liquifies, wetting all fibers, then curing to a tough, rigid result.
If you want to learn more, please visit our website.
The pressure can be applied by tooling that closes and presses the fibers. Vacuum bagging can also apply pressure when a vacuum is applied to “pull” the shape into place. A third method employs an elastic pressure bladder that uses air pressure to “push” the shape into place. The end result, after the resin is cured, is a finished part with a shape that follows a mold faithfully, with little or no shrinkage, and a rigid, tough material that exploits the two components’ best properties. Similar methods are used with glass and Kevlar® reinforcers. The completed structure is then cured at room temperature or at a slightly elevated level and then released from the mold as a finished part or product.
Polymer composites and nanocomposites are very similar in their nature. They require other processes than the more widely recognized composites of carbon fiber and GRP (glass-reinforced plastic). Whether the end result material is a nanocomposite or a macro composite depends only on the scale of the additive—macro strands or nanomaterials. In both cases, the manufacturing method is essentially identical. The reinforcer material is considered an additive and is premixed with the polymer when the pellets are first manufactured. Molded parts have evenly distributed reinforcers throughout.
Properties of composites are as diverse as the range of materials that fall within this broad classification. Under ideal conditions, the resultant properties of the composite are:
Composites are often made with a rigid matrix of epoxy resin or a less rigid but still stiff matrix of a thermoplastic polymer. This component generally lends the below primary chemical properties to the resulting material:
Some common themes in the physical properties of composites can be generalized, including:
Plastic components are generally made from a single polymer injection, or sometimes a two-stage process that overmolds rubber onto a part for specific applications such as grip and seal. They are relatively easy to manufacture, generally involving a single-stage operation. Composites, on the other hand, are always two or more co-processed materials, achieving better properties than the individual components can deliver. They are also intrinsically more complex to manufacture. They generally require manual lay-up processes and tend to be much more expensive in labor terms than simple, automatable molding operation outputs. Composites are generally intrinsically stronger than equivalent plastic parts by a large factor. This allows composite parts to deliver higher strength and reduced weight, compared with a similar plastic component.
Plastic parts are, in most regards, shape, and size unlimited. Composite parts are rarely used for very small components but can be very large, but they are quite restricted in the complexity of shapes and fine detail. Broadly, plastics are used for low-cost, high-volume applications, whereas composites are considerably more costly and are used for high-value and lower-volume tasks.
The range of composites employed in manufacture/construction is extensive, but they fall into these broad categories. These are listed below:
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.
Typical nanocomposites use the nanomaterial additive to add strength, stiffness, and other properties such as electrical or thermal conductivity to the polymer matrix. Naturally occurring nanocomposite examples are bone and shell. Nanomaterials represent significant health risks in some cases, so manufacture of these materials can be challenging.
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.
MMCs are used in aerospace industries and extreme automotive uses, delivering high strength and low weight. They are also used in electronics, medical devices, and sporting goods. The processing of MMCs is more challenging than most other classes of composites, as high temperatures and the difficulties of uniform reinforcer distribution are challenging.
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.
PMCs are widely used in aerospace, automotive, marine, and sporting goods, benefitting from light weight, high strength, and stiffness. Production of PMCs involves assembly methods such as hand lay-up and filament winding, which can be slow. Precise control over the curing process is needed, to achieve ideal material properties.
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 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.
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.
CMCs are used to make gas turbine blades, specialist rocket/aerospace components, and heat exchangers. CMCs are very costly and they remain quite brittle, which limits their use. However, this is a field of intense research, and properties are improving.
There is an increasing trend toward using natural fibers in composite manufacture, to reduce the environmental impact of materials use. Natural fibers such as jute, flax, cotton, and wood are used in a variety of ways. Automotive interior panels are commonly made from resin-bonded natural fibers which are compression molded to shape and then upholstered in plastics or leather for final surfacing. Wood fibers are added to polymers for FDM/FFF rapid prototyping filaments, to improve strength and produce a wood effect. Skateboard decks make extensive use of natural fiber reinforcement, generally in a polyester resin matrix.
CFRPs are another subset of polymer matrix composites, specific to epoxy and polyester-bonded carbon fibers. For hand lay-up purposes, carbon fiber is generally used as woven roving, with a range of weave patterns used for various types of loading and stress distribution. The fibers are pre-impregnated with thermally activated resins, so the flexible cloth is laid-up and then compressed and baked to liquify and then cure the resin to create a rigid, tough result. Carbon fiber can also be pultruded with a range of polymers, to make continuous lengths of CFRP in complex sections.
AFRPs are another subset of polymer matrix composites that employ aramid as the reinforcer. Aramid fiber composites are used in the highest-impact applications. The aramid is generally used as woven fabrics that are pre-impregnated with appropriate epoxy and polyester resins, to be processed as per carbon/glass fiber. Another aramid reinforced composite is the paper/aramid honeycomb material used in low-profile flooring panels in aviation—layered with aluminum sheets and epoxy bonded, this is a typical high-value hybrid composite.
FGCs are essentially a subset of any type of composite. These are composite materials in which the constituent parts can be modified in the application or type through the structure to tune performance. A gradual transition in properties is used to avoid stress concentrations at sudden changes. The functional grading can be: as simple as adding or altering fiber content at elevated stress points; changes in weave pattern in roving to alter load distribution; or progressive hybridization for impact resilience in regions.
FGCs are used to make lighter and more resilient aircraft and spacecraft components, such as turbine blades and rocket nozzles. Biomedical devices/implants can have varied properties regionalized according to desired tissue interactions.
A range of additive materials is integrated into various polymer 3D printing materials for FDM/FFF, SLS, and other systems. The resultant materials offer enhancement of properties such as tensile strength, bending strength, hardness/abrasion resistance, etc. Examples of 3D printable composites are
Fiber and metal additives in 3D printing materials offer some potential advantages. These are listed below:
Some 3D printing processes use a form of functional grading, by co-printing rigid and elastomeric materials in the same parts, allowing properties to be varied through a build.
There are challenges in using composites in some 3D printing processes, as listed below:
There is ongoing research into ductile magnesium matrix materials with titanium reinforcement. There is also ongoing development of metal-organic framework (MOF) polymer hybrids based on poly(urethane urea) which are reported as highly ductile. Ductility is not a common property in composites, as they tend to be a merger of a rigid, often brittle matrix and a flexible and elastic reinforcer. A prime example of this is ferroconcrete, which has virtually no ductility.
Ceramics are intrinsically brittle, and ceramic composites only marginally reduce this tendency. Ceramic turbine blades have great thermal performance but rarely exhibit good impact resilience. For more information, see our guide on Brittleness.
There are hundreds of composite materials in daily use. These are some examples:
Listed below are some applications of composite materials:
The aerospace sector is always looking for higher strength and lower weight. The ability to directly manufacture parts with carbon fiber or even have continuous-strand fibers built-in offers opportunities to achieve remarkable strength levels in low-volume parts of unlimited complexity.
This is an experimental field that is not yet widely developed for making airworthy or certified manufactured parts—but this goal gets closer all the time.
No passenger-carrying aircraft will get an airworthiness certificate if built from or using 3D-printed parts in any flight-related function. This is irrespective of the materials being composite. In drones/UAVs however, extensive use is made of such parts in development and flight testing. As a rule, serviceability issues will rule such parts out from mass production.
This article presented composite materials and explained what they are, and discusssed its types, properties, and applications. To learn more about composite materials, contact a Xometry representative.
You will get efficient and thoughtful service from NFJ.
Xometry provides a wide range of manufacturing capabilities, including 3D printing and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.
The content appearing on this webpage is for informational purposes only. Xometry makes no representation or warranty of any kind, be it expressed or implied, as to the accuracy, completeness, or validity of the information. Any performance parameters, geometric tolerances, specific design features, quality and types of materials, or processes should not be inferred to represent what will be delivered by third-party suppliers or manufacturers through Xometry’s network. Buyers seeking quotes for parts are responsible for defining the specific requirements for those parts. Please refer to our terms and conditions for more information.
Composite materials are an integral part of numerous industries, revolutionizing the way we design and manufacture products. These materials are engineered by combining two main components: a matrix and reinforcing fibers. The matrix, typically a polymer, ceramic, or metal, serves as the binding substance, providing support and transferring loads to the reinforcing phase. Meanwhile, the reinforcing fibers, commonly made of materials like carbon, glass, or aramid, are embedded within the matrix to enhance strength and performance. Essentially, composites are a synergy of materials, leveraging the distinct properties of each component to create a unified structure that surpasses the individual characteristics of its parts. Understanding the relationship between the matrix and fiber is crucial to comprehending the immense potential and diverse applications of composite materials across various fields.
Composite materials have gained substantial acclaim across various industries for their unparalleled characteristics, making them an exceptional choice for diverse applications. Here are several reasons why composite materials stand out:
Strength and Lightness: Composites offer an exceptional strength-to-weight ratio, surpassing many traditional materials like steel and aluminum. Their ability to maintain robustness while remaining significantly lighter makes them invaluable in industries where weight reduction is critical without compromising structural integrity.
Durability: These materials exhibit outstanding durability and resilience, capable of withstanding harsh environmental conditions, corrosion, and wear, which extends their lifespan far beyond that of conventional materials. Their resistance to moisture and chemicals further enhances their durability.
Safety: Composites often offer enhanced safety features, particularly in applications where impact resistance is crucial. Their ability to absorb energy makes them ideal for applications ranging from automotive to aerospace, ensuring greater safety in the event of collisions or high-impact scenarios.
Fatigue and Creep Resistance: Composite materials showcase impressive fatigue and creep resistance, meaning they can withstand prolonged stress or repeated loading cycles without significant deterioration. This property makes them highly sought-after in applications where consistent, enduring performance is essential.
Composite materials excel not only in these aspects but also in their optical characteristics, thermal resistance, and specific engineering properties tailored to meet the diverse and stringent demands of modern industries. Their continued evolution and adaptability continue to position composites as a cornerstone in innovation and technological advancements across all kinds of industries and applications.
Composite materials, with their exceptional properties, have found widespread use in a myriad of applications, not only confined to specialized industries but also in various everyday products. Their versatility, durability, and diverse characteristics have made them an integral part of numerous sectors, from construction to sports equipment, automotive manufacturing to medical devices.
Some common industries where composites play a pivotal role include:
Aerospace: Utilized in aircraft structures to reduce weight and improve fuel efficiency.
Automotive: Employed in car bodies, interior components, and structural elements for enhanced strength and reduced weight.
Marine: Used in boat hulls, masts, and components due to their resistance to corrosion and strength.
Construction: Found in bridges, buildings, and infrastructure for their durability and design flexibility.
Sports Equipment: In products like tennis rackets, golf clubs, and bicycles due to their strength and lightweight nature.
Here at SendCutSend, our customers use our online CNC machining services to cut a huge variety of composite parts in many different available composite materials. Most commonly, we have seen our composite materials used in:
Lightweight Paneling: Our CNC routed ACM is an ideal material for any paneling, framing, or structural reinforcing you may need to do at a low weight
Electronics: Materials like our high quality G10 have superior electrical properties, making it a great material to use in custom circuit boards
Carbon Fiber Components: Such as brackets, plates, and fixtures due to carbon fiber’s high strength-to-weight ratio.
Gaskets and Seals: Cork is a perfect composite material choice for gaskets and seals due to its strength and hydrophobic properties
Each composite has a totally unique set of advantages and disadvantages, lending themselves to vastly different applications. If you’re struggling to pick a composite for your project, check out our article on Choosing the Right Composite Material for Your Project.
Creating a comprehensive view of the world of composite materials involves delving into the diverse and intricate nature of their types, compositions, and applications. There are many different types of composites, with a myriad of combinations when it comes to the materials being used in each composite’s make-up. Let’s take an extensive look at six prominent types of composite materials, emphasizing their compositions, characteristics, and real-world applications.
Polymer matrix composites (PMCs) are a broad category of composites characterized by their use of a polymer-based matrix reinforced with fibers. These composites are renowned for their versatility, ease of manufacturing, and cost-effectiveness, making them highly popular across industries. A prime example is G10, which consists of glass fibers embedded in a polymer matrix, often epoxy or polyester. Our waterjet cut G10 is laminated with epoxy. The resulting material is prized for its exceptional strength-to-weight ratio, resistance to corrosion, and low cost of production. G10 is ubiquitous in the construction industry, where it is used in the production of lightweight, durable structures such as boat hulls, swimming pools, and building facades. G10 is used where durability and strength is of the utmost importance.
Metal matrix composites (MMCs) are materials that combine metal alloys with reinforcing elements such as ceramics or fibers. These composites are engineered to deliver improved mechanical properties, including enhanced strength, stiffness, and wear resistance. One standout example is aluminum reinforced with polyethylene, commonly known as ACM (Aluminum Composite Material). This composite material is highly sought after in aerospace and automotive industries, where its superior strength and lightweight nature make it ideal for critical components. In aerospace, MMCs are used in components like rocket nozzles and aircraft engine parts, while in the automotive sector, they find applications in brake rotors and engine components. We offer CNC routed ACM in two thicknesses here at SendCutSend (.118” and .236”) with the tightest possible tolerances (only +/- .005”).
Ceramic matrix composites (CMCs) are known for their exceptional resistance to high temperatures and extreme hardness. These composites consist of ceramic fibers embedded within a ceramic matrix. An exemplary material in this category is silicon carbide reinforced with silicon carbide fibers, which exhibits remarkable thermal stability and hardness. CMCs are indispensable in the aerospace industry, where they are employed in the manufacturing of components for gas turbine engines, exhaust systems, and leading edges of hypersonic vehicles. Their ability to maintain structural integrity under extreme conditions makes them essential in these applications.
Carbon matrix composites (CAMCs) comprise carbon fibers in a carbon-based matrix. This combination results in materials with extraordinary strength and exceptional lightness. Carbon-carbon composites are prime examples of CAMCs and are known for their high-temperature resistance and low thermal expansion properties. They are extensively used in aerospace structures, including aircraft brakes, nose cones, and heat shields. The unique combination of high strength and heat resistance makes carbon-carbon composites indispensable in applications where safety and reliability are paramount.
Combining the benefits of polymer matrix composites with ceramic elements results in materials that exhibit high-temperature resistance and superior strength. Carbon fiber reinforced polymer (CFRP) with a ceramic matrix is a notable illustration of this hybrid approach, and one of the more well-known and recognizable composites available. CFRP is a lightweight, high-strength material used in a wide range of applications, from aerospace components like aircraft fuselages and wings to high-end sporting equipment such as tennis rackets and golf club shafts. The hybrid nature of this composite allows for tailored performance, striking a balance between strength, weight, and thermal resistance. Our high quality, 2×2 twill weave carbon fiber is waterjet cut here at SendCutSend, giving you superior edge quality on all your carbon fiber parts with a lower risk of delamination.
Hybrid composites are composite materials that combine two or more different types of fibers or matrices. By doing so, they aim to leverage the strengths of each material, creating a material that excels in multiple aspects. A common example is aramid fibers combined with glass fibers in a polymer matrix, which offers a balance between strength, flexibility, and lightweight construction. These composites are notably used in the production of bulletproof vests, where a blend of aramid and glass fibers provides protection against ballistic threats while ensuring wearability and comfort for the user.
Composite materials encompass a wide variety of types, each tailored to meet specific industrial needs. The examples discussed above illustrate the diversity and adaptability of composites, as well as their critical role in advancing technology, improving efficiency, and enhancing safety across various industries. Whether it’s in the construction of lightweight and durable structures, the development of high-performance aerospace components, or the creation of innovative sporting equipment, composite materials continue to shape the world we live in and drive innovation in engineering and design.
A composite material is a material that joins two or more unique substances to create a material with enhanced characteristics. Polymers are often used to bind the substances together, although other binding agents are also used. Carbon fiber, fiberglass, and cork are common examples of composite materials.
Plastics are sometimes used in composites, but not all composites contain plastic. However, polymer is a common binding agent in composites. G10 is an example of a composite which utilizes a polymer (epoxy) to bind its composites together.
In the realm of composite materials, the spectrum of possibilities and applications is continually expanding. As industries evolve and technological advancements progress, the significance of these materials becomes increasingly pronounced.
Whether you’re developing a brand new technology or working on a simple side project or creating a new line of products, we are here to help you make your composite parts a reality. With our commitment to precision and innovation, our composite materials are waterjet cut or CNC routed to your exact specifications with the best possible tolerances. We can accommodate projects of any size thanks to our no minimum order quantity policy, ensuring accessibility and flexibility for both small-scale endeavors and large industrial applications. And our fast, free shipping enables seamless access to high-quality, precisely cut composite parts without the burden of added costs and hidden fees.
If your waterjet cut composite designs are ready to go, all you have to do now is upload them and get a free, instant quote today.
Contact us to discuss your requirements of Composite Powder. Our experienced sales team can help you identify the options that best suit your needs.