1. Test items

Mechanical properties test:

Tensile strength is a key indicator that determines the limit of tensile force that carbon fiber can withstand and is related to the safety of the product under stress conditions. For example, if carbon fiber composite materials are used for aircraft engine blades, their high strength can ensure that the blades do not break when rotating at high speed.

Elastic modulus reflects the rigidity of the material. High modulus carbon fiber can ensure that the structural parts are slightly deformed. For example, the supporting parts of precision instruments require carbon fiber to have stable shape retention capabilities.

Fiber structure test:

The diameter and uniformity of carbon fiber affect its performance consistency. Uneven thickness may cause local weakness of the product.

The internal crystal structure determines the material properties. Testing its graphitization degree can determine the thermal conductivity, electrical conductivity and mechanical performance potential of carbon fiber.

Chemical composition test:

The carbon content needs to be precisely controlled, which is directly related to the performance of carbon fiber. Generally, the carbon content of high-quality products is above 90%.

Excessive content of impurity elements such as sodium and potassium will reduce the quality of carbon fiber and affect its high temperature resistance and corrosion resistance.

Surface performance test:

Roughness affects the bonding strength with the matrix material. For example, when manufacturing carbon fiber reinforced composite materials, a smooth surface is conducive to resin infiltration and improves overall performance.

The type and number of surface functional groups are related to the chemical reactivity of carbon fiber when it is composited with other materials.

2. Detection method

Mechanical test method: Use a universal material testing machine to apply force to the carbon fiber sample at a standard tensile rate, record the stress-strain curve, and obtain the tensile strength and elastic modulus.

Microscope observation method: Use a scanning electron microscope (SEM) to observe the microscopic morphology, diameter and internal crystal structure of the fiber surface, and intuitively present the fine characteristics of the carbon fiber.

Spectroscopic analysis method: With the help of X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR) and other technologies, analyze the chemical composition and surface functional groups, and determine the type and content of elements.

Contact angle measurement method: By measuring the contact angle of the liquid on the carbon fiber surface, the surface energy and roughness are calculated, and its affinity with the matrix material is evaluated.

3. Testing standards

International standards: ISO standards cover mechanical, physical performance indicators and test specifications, providing a unified scale for global carbon fiber trade and application, and promoting international exchanges and cooperation.

National standards: Based on national conditions and industrial needs, my country has refined and formulated GB/T series standards to stipulate the quality requirements of carbon fiber in key areas such as aviation and automobiles to ensure the foundation of domestic industries.

Industry and enterprise standards: Industry associations such as aerospace and wind power have introduced strict standards for special working conditions; top companies have stricter internal standards to highlight their advantages, such as high-end sports goods manufacturers set exclusive indicators for the appearance and feel of carbon fiber.

5. Significance of testing

Ensure application safety: In the field of aerospace, accurate testing ensures the quality of components and prevents flight accidents; in the automotive field, avoid collision hazards caused by material defects and protect life safety.

Promote industrial upgrading: Based on testing feedback, enterprises optimize production processes and improve carbon fiber performance, prompting my country to move from a major material country to a strong country and enhance international competitiveness.

Expand application boundaries: With the advancement of testing technology, the potential of carbon fiber is continuously explored to provide high-performance material support for emerging fields such as new energy and deep-sea exploration, creating more possibilities.