Carbon fiber-reinforced resin-based composite materials have been widely used in several industries such as aerospace technology, home scooters, and high-tech electronics due to their lightweight, high working strength, and strong corrosion resistance. Because of its remarkable product performance in humid and high-temperature environments, heavy temperature, and moderate contract control, this article will longitudinally study the changes in working performance and mechanism of carbon fiber reinforced composite materials in harsh environments with uncontrollable humid temperatures, and combine them with specific Experimental content and application cases are analyzed.
An environment with uncontrollable humidity and temperature has a greater impact on the performance and mechanism of carbon fiber composite materials. From a mechanical point of view, a warm aging environment will cause damage to the interface between the resin and the fiber. Microscopically, the resin and fiber will be separated. This interface The separation will lead to a decrease in the overall performance of the composite material, thereby affecting the mechanical properties. From a macro perspective, the mechanical properties of composite materials will be significantly reduced, posing a threat to the safety of the overall structure.
Humid thermal environments can also cause performance degradation:
Tensile strength: The tensile strength of composite materials decreases, especially under conditions of high humidity and temperature; Interlaminar shear strength: The destruction of the interface between resin and fiber leads to a decrease in the interlaminar shear strength of composite materials; Modulus: Tensile modulus Volume dropped slightly.
In the document "Comparative Study on Moisture and Heat Aging Properties of Different Types of Fiber Reinforced Composite Materials", unidirectional carbon fiber composites (CFRP), glass fiber composites (GFRP), and flax fiber composites (FRP) with a carbon fiber content of 60%6 were conducted. A warm-heat aging test was performed, and the experiment showed that after aging in a hot and humid environment, the tensile strength and interlaminar shear strength of glass fiber composite materials decreased significantly, and the tensile modulus decreased slightly. After drying, the tensile properties recovered, but the interlaminar shear strength was difficult to heal. It can be seen that the performance degradation such as glass fiber hydrolysis and interface debonding that occurs during the aging process of glass fiber composite materials is an irreversible change.
Flax fiber composites will plasticize after absorbing water, and the tensile strength will increase slightly, while the tensile modulus and interlaminar shear strength will remain stable after a sharp decrease. After drying, the tensile strength cannot be restored or even decreases significantly, while the tensile modulus and interlaminar shear strength increase significantly. This phenomenon is closely related to changes such as moisture plasticization, expansion, and degradation of fibers and matrix.
Carbon fiber composites are different from the two materials mentioned above. As the aging time increases, the tensile properties of carbon fiber composites almost remain unchanged, but the interlaminar shear strength decreases slightly. After drying, the tensile properties and interlayer shear properties return to their original state. It can be seen that even if the carbon fiber composite material is affected during the aging process in a humid and hot environment, it will return to its original shape after drying and has good humid and heat resistance.
Although carbon fiber composite materials have better resistance to moisture and heat, specific product adjustments are still required in actual production applications to ensure better application of the product. In the report "Research on the Warm Parts Performance of Domestic CCF30 Carbon Fiber and CC[300/EH503R3 Composite Materials", a study was conducted on the aging of specific carbon fiber resin-based composite materials in hot and humid environments. The study proved that: CCF300/EH503R3 composite materials were tested in 1,000-state conditions at room temperature. Under the environment, 90% of the tensile fracture morphology shows matrix damage, and the carbon fiber has no obvious fracture. The surface of the mesh fiber is wrapped with a large amount of resin, which shows that the carbon fiber and resin have strong interfacial bonding properties. In the 93°C/dry test environment, a small amount of resin tearing and slight carbon fiber debonding occurred. After treatment in a humid heat environment, due to the increase in the temperature of the test environment, a small number of cracks appeared along the fiber axis, and the amount of resin wrapped on the fiber surface decreased. Debonding increases and the bonding force between fiber and resin weakens. However, at 132℃/wet test temperature, carbon fiber and resin can still be tightly combined, which shows that CCF300/EH503R3 composite material has excellent interface performance and moisture and heat resistance.
In summary, based on actual products and past production experience, we can design a product design plan for carbon fiber composite materials in a targeted manner, measure performance requirements according to product application conditions, and further start from the resin matrix, carbon fiber precursor model, modification scheme, molding process, etc., to specify a reasonable design plan to ensure its actual application performance. This is exactly the underlying logic of China to look at the product drawings first and then understand its product application requirements, and then give the design plan later.
With the continuous progress in the field of materials, the wet and heat performance of carbon fiber composite materials can be further improved through interface modification and the improvement of precursor performance, and carbon fiber composite derivatives will also play an indispensable and important role in more fields.
