Application - carbon fiber

Properties and applications of carbon fibers

Carbon fiber is the reinforcement material of advanced composite materials, which has a series of advantages such as light weight, high strength, high modulus, chemical corrosion resistance and small thermal expansion coefficient, etc., which can be summarized as follows:

I. Light weight, high strength and high modulus

The density of carbon fiber is 1.6-2.5g/cm3, and the tensile strength of carbon fiber is above 2.2Gpa. Therefore, with high specific strength and specific modulus, it is more than 7 times higher than the majority of metal specific strength, specific modulus is more than 5 times of metal. Because of this advantage, its composite materials can be widely used in aerospace, automotive industry, sports equipment and so on.

2. Small coefficient of thermal expansion

The thermal expansion coefficient of most carbon fibers is negative (-0.5 ~ -1.6) ×10-6/K indoors, zero at 200 ~ 400℃, and 1.5×10-6/K at less than 1000℃. The expansion coefficient of the composite material made of it is naturally more stable and can be used as a standard weighing tool.

3. Good thermal conductivity

In general, inorganic and organic materials have poor thermal conductivity, but carbon fiber is close to steel. This advantage can be used as solar collector materials, heat transfer uniform thermal shell materials.

4. Good resistance to chemical corrosion

The composition of carbon fiber shows that it is almost pure carbon, which is one of the most stable elements. It is stable to acids, bases and organic chemicals in addition to strong oxidizing acids, and can be made into a variety of chemical preservative products.

5. Good abrasion resistance

Carbon fiber and metal grinding, very little wear, with carbon fiber to replace asbestos made of advanced friction materials, has been used as aircraft and car brake pad material.

6. Good high temperature resistance

The performance of carbon fiber is very stable below 400℃, and even at 1000℃ there is still no great change. The high temperature resistance of composite material mainly depends on the heat resistance of matrix. The long-term heat resistance of resin matrix composite material is only up to about 300℃. The high temperature resistance of ceramic, carbon and metal matrix composite material can match with carbon fiber itself. So carbon fiber composites are widely used in aerospace industry as high temperature resistant materials.

7. Outstanding damping with excellent through-sonar

These two characteristics can be used as the structural materials of submarine, such as the sonar deflector of submarine.

8. High X-ray transmittance

This feature has been used in medical devices.

9. High fatigue strength

The structure of carbon fiber is stable. After millions of cycle tests of stress fatigue, the strength retention rate of the composite material is still 60%, while that of steel is 40%, aluminum is 30%, and glass fiber reinforced plastic is only 20%-25%. Therefore, the safety factor of the designed products is the lowest for carbon fiber composite materials.