Carbon Fiber Testing

Carbon fiber is a high‑strength and high‑modulus fibrous material with carbon content above 90%, manufactured by carbonization and graphitization of organic fibers. Featuring light weight, high strength, high temperature resistance, corrosion resistance and good electrical conductivity, carbon fiber is widely used in aerospace, automobile industry, sports equipment, building reinforcement, wind power generation and other fields. Testing institutions carry out systematic tests on carbon fiber to verify that physical, chemical and thermal properties meet relevant standards, and provide data support for product quality control and application safety.

Test Items

1. Tensile Strength: Maximum load‑bearing capacity of carbon fiber under tensile load.

2. Tensile Modulus: Stiffness characteristic of carbon fiber under tensile condition.

3. Breaking Elongation: Deformation capacity of carbon fiber before fracture.

4. Density: Mass per unit volume of carbon fiber.

5. Fiber Diameter: Cross‑section dimension measurement of single carbon fiber filament.

6. Carbon Content: Mass percentage of carbon element in carbon fiber.

7. Ash Content: Residual substance content after carbon fiber combustion.

8. Moisture Content: Water content in carbon fiber.

9. Sizing Agent Content: Proportion of sizing agent coated on carbon fiber surface.

10. Electrical Conductivity: Resistivity and conductive characteristics measurement.

11. Thermal Conductivity: Heat transfer capability of carbon fiber.

12. Coefficient of Thermal Expansion: Dimensional stability against temperature variation.

13. Heat Resistance: Performance retention capability under high‑temperature environment.

14. Onset Oxidation Temperature: Temperature point where carbon fiber starts oxidation.

15. Interlaminar Shear Strength: Interfacial bonding performance evaluation for carbon fiber composites.

16. Flexural Strength: Strength under bending load condition.

17. Flexural Modulus: Stiffness characteristic under bending load.

18. Compressive Strength: Load‑bearing capacity under compressive load.

19. Impact Strength: Resistance capability against impact load.

20. Linear Density of Fiber Tow: Mass per unit length of carbon fiber tow.

21. Filament Breakage Rate: Proportion of broken filaments inside carbon fiber tow.

22. Fuzz Content: Amount of loose fuzz on carbon fiber surface.

23. Porosity: Pore content measurement of carbon fiber composites.

24. Fiber Volume Fraction: Volume percentage of carbon fiber within composites.

25. Surface Morphology: Micro‑morphology observation of carbon fiber surface.

Test Scope

1. PAN‑based carbon fiber

2. Pitch‑based carbon fiber

3. Rayon‑based carbon fiber

4. High‑strength carbon fiber

5. High‑modulus carbon fiber

6. High‑strength high‑modulus carbon fiber

7. Intermediate‑modulus carbon fiber

8. Low‑modulus carbon fiber

9. Large‑tow carbon fiber

10. Small‑tow carbon fiber

11. Carbon fiber continuous filament

12. Chopped carbon fiber

13. Carbon fiber fabric

14. Carbon fiber prepreg

15. Carbon fiber composite material

16. Carbon fiber reinforced plastic

17. Carbon fiber reinforced thermoplastic

18. Carbon fiber reinforced thermoset plastic

19. Carbon fiber felt

20. Carbon fiber paper

21. Carbon fiber cloth

22. Carbon fiber tape

23. Carbon fiber tube

24. Carbon fiber plate

25. Activated carbon fiber

Applicable Standards

1. GB/T 3362, Test method for tensile properties of carbon fiber multifilament

2. GB/T 26749, Determination of density for carbon fiber

3. GB/T 29761, Determination of sizing agent content for carbon fiber

4. GB/T 33501, Test method for thermal conductivity of carbon fiber and its composites

5. GB/T 3365, Test method for void content and fiber volume fraction of carbon‑fiber‑reinforced plastics

6. ASTM D3379, Standard Test Method for Tensile Properties of Single Carbon Fiber Filaments

7. ASTM D2343, Standard Test Method for Density of Glass, Carbon, and Aramid Fibers

8. ISO 10548, Carbon fibre — Determination of size content

9. ISO 11566, Carbon fibre — Determination of tensile properties of single‑filament specimens

10. JIS R7601, Test methods for carbon fibers

11. GB/T 3354, Test method for tensile properties of oriented fiber‑reinforced plastics

12. GB/T 3355, Test method for longitudinal and transverse shear properties of fiber‑reinforced plastics

13. GB/T 3356, Test method for flexural properties of unidirectional fiber‑reinforced plastics

14. GB/T 1447, Test method for tensile properties of fiber‑reinforced plastics

15. GB/T 1449, Test method for flexural properties of fiber‑reinforced plastics

Test Instruments

1. Universal Electronic Testing Machine

2. Fiber Tensile Tester

3. Scanning Electron Microscope (SEM)

4. Thermogravimetric Analyzer (TGA)

5. Differential Scanning Calorimeter (DSC)

6. Thermal Conductivity Tester

7. Fiber Fineness Analyzer

8. Elemental Analyzer

9. Carbon‑Sulfur Analyzer

10. Resistivity Tester

11. High‑Temperature Furnace

12. Metallurgical Microscope

13. Fourier‑Transform Infrared Spectrometer (FTIR)

14. X‑ray Diffractometer (XRD)

15. Dynamic Mechanical Analyzer (DMA)

Summary

As a high‑performance fibrous material, carbon fiber testing covers physical properties, chemical composition, thermal performance, electrical performance and other dimensions. Standardized testing procedures and scientific test methods can obtain accurate performance parameters, providing reliable basis for material selection, product design and quality control. Testing institutions shall perform tests complying with national standards and industry specifications to guarantee accuracy and traceability of test data, and support the healthy development of carbon‑fiber industry.