The difference between carbon fiber PEEK and unfilled PEEK

PEEK CF30 is a carbon fiber reinforced - PEEK made from 30% by weight of short cut carbon fibers added to a PEEK matrix. Carbon PEEK is considered one of the strongest of all thermoplastics at room temperature because of its superior properties, which, combined with very good abrasion and wear resistance, make it ideal for replacing metals in more extreme environments. Carbon fiber PEEK is a composite material that is a high-performance polymer. Compared to pure PEEK, carbon fiber provides higher mechanical strength, high-temperature properties and excellent chemical resistance, making it the material of choice for the harshest environments.The key properties of PEEK CF30 are as follows:

PEEK CF30 Mechanical Properties

Reinforcement with 10% short-cut carbon fibers increases the compressive strength, stiffness, and load capacity of PEEK. Compared to PEEK, carbon PEEK has higher mechanical properties. It has an ultimate tensile strength (UTS) of 138 MPa, which is 35% stronger than PEEK and some aluminum alloys such as Al 6063.

PEEK CF30% also has a very high tensile modulus of up to 14 GPa, which explains its brittle behavior and excellent toughness. It is 76% harder than PEEK, also because its tensile elongation is ten times lower than that of PEEK, so when it is stressed, it does not deform before rupture.PEEK CF30 performs impressively against compressive loads: its compressive strength is approximately 229 MPa.

Thermal Properties of PEEK CF30
What are the thermal effects of carbon fibers on PEEK substrates? They are the gospel: Carbon PEEK has a relatively high heat deflection temperature (HDT) of up to 280°C, compared to about 150°C for pure PEEK. this increase is due to the improved thermal stability of carbon fibers compared to pure PEEK. the thermal conductivity of PEEK CF30 is higher than that of unloaded PEEK, so due to its lower coefficient of linear thermal expansion (CLTE), it is more stable at high and lower temperatures.

Physical Properties of PEEK CF30
3D printed PEEK is black in color, and when fully crystallized, it appears slightly brighter with some gray-blue tones. The addition of carbon fibers to a PEEK substrate does not significantly increase its density: only 1.33 g/cm3. One of the physical parameters that is significantly affected by carbon reinforcement is the bulk resistivity: because carbon fibers are electrically conductive, they improve the electrical properties of the insulating PEEK substrate. Carbon fibers also affect the material's hardness: tested at 87 Shore D, they make it very tough and rank among the top Shore hardness scales for polymers. Like PEEK, PEEK CF30 is inherently flame retardant (UL94 V0 FST): it virtually does not burn and produces no toxic fumes when it does, so it is safe to use in applications where there is a risk of fire, such as in the energy industry. This may sound counterintuitive, but due to the self-lubricating properties of carbon fiber and the higher thermal conductivity of the particles, PEEK CF30 typically provides low dry friction: instead of concentrating on the surface, heat penetrates into the volume. As a result, the coefficient of friction of carbon fiber-reinforced PEEK is one-third lower than that of PEEK.

Nonetheless, short-cut carbon fibers in any composite increase its roughness: these composites can scratch the materials they come in contact with, so care is needed in applications where they come in contact with softer materials. Carbon fibers are not susceptible to UV degradation, so PEEK CF30 is fairly resistant to UV radiation and also has good resistance to high-energy radiation. Carbon fibers have weak resistance to magnetic effects in static magnetic fields.