Carbon fiber composite materials are increasingly used in various fields

Carbon fiber is a high-strength, ultra-lightweight inorganic polymer fiber material with a carbon content of more than 95%. It is stronger than steel and lighter than aluminum. It not only retains the inherent characteristics of carbon materials, but also has the soft processability of fiber materials. It is a material that is "soft on the outside and rigid on the inside".

Today, we find new uses for carbon fiber almost every day. These tiny filaments, which currently come in a variety of functional shapes, are only one-tenth the thickness of a human hair. The fibers are processed into fabrics that can be used in subsequent molding processes and formed into tubes and sheets for construction, or as regular threads for filament winding.

At first, carbon fiber was mainly used in military industry and aerospace. After continuous development, its application fields are expanding to industrial fields and ordinary civilian fields. With the rapid development of science and technology, carbon fiber is also used in the repair, renewal and reinforcement of infrastructure, the development of new energy and the production of propellers and blades for wind turbines; the manufacturing of automobile braking systems, rotating shafts, car bodies, etc.; applications in the electronic field mainly include High-precision antennas for communications, broadcasting, earth observation, space exploration, and various aircraft.

In terms of cultural and sports products, carbon fiber materials have been promoted from fishing rods and golf clubs to tennis rackets, badminton rackets, ice and snow sports equipment, water sports equipment, etc. Among them, golf clubs, tennis rackets and fishing rods are carbon fiber composite materials for sporting goods. The three pillar products account for about 80% of this type of products.

01

Advantages of carbon fiber composites

Composite materials are slowly replacing traditional materials. Common composite materials are good substitutes for traditional materials such as metal and wood in various fields.

1. Composite materials have high specific strength

CFRP materials offer optimal strength-to-weight ratio, corrosion resistance, stiffness and durability. Due to its low density and tensile strength, carbon fiber is an excellent alternative to heavy metals like steel because it is lightweight. The inherent corrosion resistance of thermoset resins allows CFRP products to have a longer product life than standard metal materials because they will not rust or corrode.

The high specific strength of composite materials is its greatest advantage. Although carbon fiber is stronger and stiffer than these two materials per unit weight, it weighs approximately 25% of steel and 70% of aluminum. Multilayer composite laminates absorb more energy than traditional single layers of steel, allowing high-end automotive engineers to reduce vehicle weight by 60% while improving crash safety.

2. Composite materials provide possibilities for new designs

Composite materials offer design alternatives that are difficult to achieve with traditional materials. Composite materials can strengthen items; a single composite part can replace an entire assembly of metal parts.

Any surface treatment, from smooth to textured, can be imitated by changing the surface texture. Because fiberglass can be molded into a wide variety of boat designs, composite materials make up more than 90 percent of recreational boat hulls. Long-term savings from these advantages include lower maintenance costs and shorter production times.

3. Composite materials are durable

Composite materials will not rust regardless of the conditions (although they are susceptible to corrosion when combined with metal components). Composites are tougher than most polymers but tougher than metals.

Thanks to their excellent dimensional stability, they maintain their shape whether hot or cold, wet or dry. Therefore, they are the material of choice for outdoor structures such as wind turbine blades.

Engineers prefer composites over traditional materials because they are more cost-effective in maintaining and providing long-term stability of buildings that last for decades.

4. Composite material manufacturing is becoming simpler

In the past, engineers had to create composites through complex lay-up procedures that were time-consuming and limited design geometries. Today, this has changed with Digital Composite Manufacturing (DCM).

A unique manufacturing method called DCM can create composite parts without the need for manual labor. With DCM, composite materials can be customized in three dimensions, locally or globally, to meet the ideal strength, density and flexibility of a project. Thanks to DCM, engineers now have the freedom to 3D print and design high-performance composite materials.

By adding highly graphitized fibers, carbon fiber composites have very high thermal conductivity. To better remove unwanted heat from electronic machinery, carbon fiber reinforced composite materials are also recommended in electronic systems.

02

Application of carbon fiber composite materials in sports and leisure products

The application fields of carbon fiber sporting goods can be divided into two general directions. One is competitive sports, which mainly emphasizes high precision, higher and faster, and the other is used for daily fitness and leisure, which requires appropriate cost performance. At present, the products with the largest consumption of carbon fiber in the field of sporting goods are:

1. Bicycle

Steel is the most durable material for bicycles. It has good elasticity and low cost. However, due to its high density, it is easy to rust and fatigue. Aluminum alloy is a commonly used material on the market. It is light in weight and will not rust. However, its elasticity is too poor, it is easy to fatigue, and the riding comfort is not good. The density of magnesium alloy is smaller than that of aluminum alloy, and its basic properties are similar to those of aluminum alloy. The fatigue resistance of titanium alloy is better than other metal materials, but the price is high and the specific gravity has no advantage. Carbon fiber composite materials have high strength, good elasticity, light density, and corrosion resistance. Bicycles produced from carbon fiber composite materials have the following characteristics:

Effectively reduces the overall weight of the bicycle

The density of carbon fiber resin matrix composites is generally only 1.6. It is only one-fifth of steel and can reduce weight by about 40% compared with aluminum. There is a saying in the bicycle industry that if the weight is reduced by 1g, the price can increase by US$1. A carbon fiber composite bicycle frame is one-quarter lighter than an aluminum alloy frame. Light weight can reduce physical energy loss and increase riding speed.

Overall body rigidity is high

A frame with good stiffness is conducive to the conversion of driving force and improves the handling performance of the bicycle. Carbon fiber composite bicycles have a strong structure and are not easily deformed. Practice has proven that its frame rigidity is no less than that of molybdenum steel frame.

Good shock resistance

The natural frequency of the structure is not only related to the structural shape, but also proportional to the square of the specific modulus of the material. A high natural frequency can avoid early damage caused by resonance under working conditions. According to reports, tests on frames with the same shape and size show that it takes 9 seconds for an aluminum alloy frame to stop vibrating, while a carbon fiber composite material with an extremely high natural frequency only takes 2.5 seconds to stop. The composite material has good damping properties. Reduces the bumps of the bicycle and improves riding comfort.

Good safety

The matrix in carbon fiber composite materials surrounds independent carbon fibers in the form of a continuous phase, forming a dynamic and uncertain system. When the material is impacted, when a small number of fibers break, the load will be quickly redistributed to the unbroken fibers. In this way, the structure can continue to bear the load, which greatly improves the safety of riding. It is difficult to observe obvious signs of fatigue damage of general metal materials, and the damage is often sudden. However, carbon fiber composite frames have very good fatigue resistance, and obvious signs can be observed before damage. Research shows that the impact resistance test of a carbon fiber composite frame can exceed one million times.

Increased freedom in structural design

Carbon fiber composite materials have anisotropic characteristics. This characteristic of composite materials can be used to arrange and lay the fibers according to the direction and size of the load when the bicycle is traveling. The flexibility of composite material manufacturing facilitates the design of structures of various shapes. For example, a streamlined bicycle can be designed according to aerodynamic principles, which is beautiful and practical, and can easily achieve the best cost performance.

Good corrosion resistance

Polymer materials have good resistance to acid, alkali and industrial atmosphere. Therefore, bicycle frames made of carbon fiber composite materials have excellent acid and alkali corrosion resistance.

Recently, French sports car manufacturer Bugatti and Dutch bicycle manufacturer PG jointly released the world's lightest bicycle. The bike's design is inspired by Bugatti's Chiron sports racing car. It is made of carbon fiber composite materials and weighs only 11 pounds (approximately 4.99kg). According to Architectural Digestc, the bicycle is 95% made of carbon fiber composite materials.

The Czech Technical University in Prague uses an automated filament winding process combined with the Integrated Loop Technology (ILT) developed for continuous fiber tube connections to produce bicycle frames, as well as related component parts. ILT is a process that combines structural composite elements such as tubes with connecting parts. All parts are molded in one piece and assembled later.

2. Fishing rod

For fishing enthusiasts, how do you decide which fishing rod is the best? To sum it up, it is mainly reflected in three points: thin, light and strong. Therefore, a fishing rod with excellent performance needs to meet two characteristics: high stiffness and lightweight.

With the emergence and development of carbon fiber, it provides fishing rods with high specific strength and high specific modulus, making these fishing rods become lighter and lighter. Therefore, today's fishing rods are basically called "carbon fiber fishing rods" ".

Fishing rods made of carbon fiber reinforced composite materials are much lighter than GFRP products, so they consume less energy when withdrawing the rod, and the withdrawal distance is about 20% farther than the latter. The fishing rod made of CFRP is long, good and rigid. The fishing rod can recover quickly after bending, making it more sensitive in delivering bait. Carbon fiber reinforced plastic can also be used to make fishing gear rolls, which weigh no more than 140 grams, but have high fatigue strength and friction resistance, so they have a long service life.

Advantages of carbon fiber composite fishing rods: Due to their lightweight, high stiffness and other characteristics, they are widely praised. In the fishing process, the advantages of carbon fiber fishing rods are reflected in the following aspects:

Since carbon fiber fishing rods are lighter and thinner, these rods can be easily maneuvered with one hand

Because it is lightweight, it prevents user fatigue

Carbon fiber allows for longer lengths in fishing rods, and longer fishing rods mean wider fishing areas can be covered

Carbon fiber fishing rods are more responsive to fish

Carbon fiber fishing rods have made anglers more and more enthusiastic year after year, and these carbon fiber fishing rods have also made fishing a popular recreational activity rather than a basic sport, which has undoubtedly created a new market for the carbon fiber field.

(3) Tennis rackets and badminton rackets

The development trend of tennis rackets is towards larger size and lighter weight. At present, most high- and mid-range tennis rackets in the world are made of carbon fiber composite materials. Large tennis rackets need to be made of carbon fiber composite materials that are light in weight, specific strength and large in specific mold. It can withstand stronger string tension than a wooden racket frame to ensure that it does not deform when hitting the ball. The carbon fiber composite material with good vibration absorption and damping properties not only gives athletes a sense of comfort, but also allows the tennis ball to gain a greater initial speed.

The tennis racket made of composite materials is light but strong, has high rigidity and small strain, which can reduce the deviation of the ball when it comes into contact with the racket. At the same time, CFRP has good damping, which can extend the contact time between the gut string and the ball, so that the tennis ball can be Larger acceleration. For example, the contact time of a wooden racket is 4.33 milliseconds, that of steel is 4.09 milliseconds, and that of CFRP is 4.66 milliseconds. The corresponding initial velocities of the ball are 1.38 kilometers/hour, 149.6 kilometers/hour, and 157.4 kilometers/hour respectively. .

The badminton racket made of carbon fiber reinforced composite material (CFRP) is characterized by its light weight and high rigidity, which avoids the handle breakage caused by insufficient rigidity of wooden products. It also has a vibration-absorbing function and good resilience, making it easier to hit the ball and The ball return distance is long and the ball landing accuracy is high.

4. Golf clubs

In 1972, the United States first used carbon fiber composite materials to make clubs. By 1998, the number of carbon fiber golf clubs greatly exceeded that of steel clubs. Golf clubs are composed of grips, shafts, and club heads. Golf clubs made of carbon fiber composite materials can reduce weight by about 10% to 40%. According to the law of conservation of momentum, when the total weight of the golf club is constant, a top-heavy club and a light club can increase the swing speed and allow the ball to obtain a greater initial velocity. In addition, carbon fiber composite materials have high damping properties, allowing the ball to be hit longer and the ball to be hit farther.

5. Kayaking

By using Kevlar, an aramid fiber commonly used in ballistics, in kayaks, you can ensure that a well-structured boat will resist cracking and shattering. When graphene and carbon fiber materials are used in canoes and boat hulls, they can not only increase the hull's operating strength and reduce weight, but also increase the sliding distance.

6. Racing

In the 1980s, when the McLaren F1 team used carbon fiber materials to build its racing chassis, their racing cars dominated the field. As a result, McLaren's approach was imitated by other teams, and later fed back to various supercars, high-performance cars and civilian cars.

At present, the application of carbon fiber in the automotive industry is mainly divided into two types: dry and wet. Among them, dry carbon fiber has less residual resin during manufacturing, the molded parts are stronger and more expensive, so it is widely used by major ultra-luxury brands.

The resin content in wet carbon fiber is higher, so the component strength and manufacturing cost will be much cheaper than dry carbon fiber. But whether it is dry or wet carbon fiber, it has better performance than conventional materials.

The body of the Ares AMR Pro uses a special fluorescent green paint, and also adds a carbon fiber decorative panel where the arrangement of carbon wires can be seen. The lines of the vehicle are more slender, and the side rearview mirrors have also been changed to be more aerodynamic. Mechanical design, multi-piece ventilation openings are used behind the front fenders, which can better guide the air in the wheel arches. The side skirts that are almost touching the ground are connected to the front and rear wheel eyebrows. The gull-wing door design is also very charming. , 20-inch front wheels and 21-inch rear wheels are equipped with flat wide tires and rembo ceramic carbon fiber brake systems, making the vehicle look more handsome.

The interior of the car also copies the classic design of the F1 formula racing car. The integrated carbon fiber cockpit makes the vehicle more rigid. The roof, cockpit and chassis are all designed with carbon fiber. The vehicle is more rigid and the road feedback is more realistic. , more positive. The large area of suede material echoes the exposed carbon fiber material. The center console is equipped with a rounded rectangular steering wheel. There is an LCD display screen in the middle of the steering wheel to display basic information about the vehicle. The two floating LCD screens are angled at different angles. On the driving side, the integrated carbon fiber racing seat is lightweight and can also provide better wrapping and support for the driver.

03

Carbon fiber recycling

Carbon fiber composite materials are becoming increasingly popular, and their use is increasing year by year. Recycling these materials remains difficult but still necessary at European level for environmental, economic and legislative reasons. At IMT Mines Albi, researchers are studying steam pyrolysis to recover carbon fibers.

The process developed by Albi researchers is called "steam pyrolysis" and combines these two processes. Currently, moving towards large-scale reuse of carbon fiber is one of the most promising solutions in the world. Apart from Albi, there are only a few other research centers in the world working on this topic (mainly in Japan, China and South Korea).

The simplest way to reuse carbon fiber is to spread the interconnected fiber bundles out on a flat surface and reuse them in this form as carbon felt. Therefore, they will be used to make composites for decorative parts rather than structural parts. The size of the recycled fibers can also be further reduced to serve as reinforcement for polymer particles.

Slicing and reshaping is also a common recycling method for thermoplastic resins. When the degree of fiber orientation is similar, the volume content of carbon fiber is the main factor affecting the mechanical properties of the recycled composite material. The modulus value of the recycled carbon fiber reinforced composite material mainly depends on the length of the carbon fiber, and the strength value depends on the fiber and resin. quality of impregnation. Through industrial optimization, the slicing and reshaping method can realize low-cost and repeated recycling of carbon fiber composite materials, which can meet the application of carbon fiber composite materials in general civilian fields. Recently, in addition to the aerospace field, continuous carbon fiber reinforced thermoplastic composite materials have also been gradually used in orthopedic surgical medical devices, electronic appliances, high-end industries and other fields.

Article from internet.