Carbon Fiber Hardness?

[BriellaLee]

Carbon fiber material is an ultra-hard material that is 10 times harder than ordinary steel, second only to the hardness of diamond. Below is relevant information about carbon fiber: 1. Composition of carbon fiber: Carbon fiber is formed by stacking organic polymer fibers with extremely high carbon content in the direction of fiber bundles. The currently recognized high hardness and ultra-strong shear resistance are not entirely due to material properties. There is a decisive factor involved, which is the critical gap. When the stacking between fibers is below a certain critical value, the fiber porosity index between them determines the fiber's hardness, shear resistance, and tensile resistance. 2. Reasons for hardness reduction: The critical porosity that causes a decline in material mechanical properties is 1%-4%. When the porosity volume content is in the range of 0-4%, for every 1% increase in porosity volume content, the interlaminar shear strength decreases by approximately 7%. Moreover, the higher the porosity content, the larger the pore size, significantly reducing the area of interlaminar interfaces in the laminate. When the material is under stress, it is prone to damage along the interlaminar direction, which is also why interlaminar shear strength is relatively sensitive to porosity.