Polyamide 6 with 10% carbon fiber reinforcement, commonly abbreviated as PA6 CF10, represents a sophisticated engineering thermoplastic that bridges the performance gap between standard unfilled nylon and heavily reinforced composites. For engineers and procurement specialists evaluating materials for precision components, PA6 CF10 offers an exceptional balance of mechanical strength, dimensional stability, and machinability. This comprehensive guide examines the material’s composition, mechanical and physical properties, machining considerations, and real-world applications, providing the technical depth required for informed material selection in CNC machining projects.
化学組成と材料組織
PA6 CF10 is a semi-crystalline thermoplastic based on polyamide 6 (also known as nylon 6), reinforced with approximately 10% by weight of chopped carbon fibers. The carbon fiber reinforcement fundamentally alters the material’s mechanical behavior, thermal characteristics, and dimensional stability compared to unfilled PA6. Understanding the composition helps engineers predict how the material will perform under various loading conditions and environmental exposures.
Base Polymer: Polyamide 6
Polyamide 6 is synthesized through the ring-opening polymerization of caprolactam, a monomer containing six carbon atoms, which gives the polymer its designation. The molecular structure features repeating amide groups (-CO-NH-) separated by five methylene groups. These amide groups form strong hydrogen bonds between adjacent polymer chains, contributing to the material’s excellent toughness, wear resistance, and chemical compatibility. The semi-crystalline nature of PA6 provides a crystalline melting point around 220-225°C, while the glass transition temperature typically falls between 40-60°C depending on moisture content. The polymer’s ability to absorb moisture—up to 3% by weight at 50% relative humidity—significantly influences its mechanical properties and dimensional behavior.
Carbon Fiber Reinforcement at 10% Loading
The 10% carbon fiber content in PA6 CF10 represents a moderate reinforcement level that provides meaningful improvements without the processing difficulties associated with higher loadings. Carbon fibers used in this application are typically PAN-based (polyacrylonitrile precursor) chopped fibers, ranging from 6 to 7 micrometers in diameter and 200 to 300 micrometers in length after processing. The fibers are treated with a sizing agent to promote adhesion with the polyamide matrix, ensuring effective load transfer from the polymer to the fibers. At 10% loading, the fibers provide a 30-50% increase in tensile and flexural modulus compared to unfilled PA6, while maintaining excellent surface finish and machinability. The fiber orientation within molded or extruded stock shapes is not perfectly isotropic; fibers tend to align in the flow direction during processing, creating slight anisotropy in mechanical properties that engineers should consider during design.
Mechanical Properties of PA6 CF10
The mechanical property profile of PA6 CF10 makes it suitable for structural applications requiring higher stiffness and lower creep than unfilled nylon. The carbon fiber reinforcement enhances strength, modulus, and fatigue resistance while maintaining the inherent toughness of the polyamide matrix. These properties are moisture-dependent, and engineers must account for the service environment when designing components.
Tensile and Flexural Performance
PA6 CF10 exhibits tensile strength typically in the range of 100-130 MPa when dry-as-molded, compared to 60-80 MPa for unfilled PA6. The tensile modulus increases from approximately 2.5-3.0 GPa for unfilled material to 6-8 GPa with 10% carbon fiber reinforcement. Flexural strength follows a similar trend, with values typically reaching 150-180 MPa. These improvements allow designers to reduce wall thickness or increase load-bearing capacity without changing part geometry. However, the material’s ductility decreases with fiber addition; elongation at break drops from 20-30% for unfilled PA6 to 3-5% for PA6 CF10. This reduced ductility means the material is more susceptible to stress concentration at sharp corners or notches, requiring careful attention to fillet radii in part design.
Impact Resistance and Fatigue Behavior
Notched Izod impact strength for PA6 CF10 typically ranges from 4-6 kJ/m², which is lower than unfilled PA6 (6-10 kJ/m²) but still acceptable for many industrial applications. The carbon fibers create preferential crack paths, reducing the material’s ability to absorb impact energy through plastic deformation. Fatigue performance, however, improves significantly with carbon fiber reinforcement. The fibers carry a larger portion of cyclic loads, reducing stress on the polymer matrix and improving fatigue life by a factor of 2-3 compared to unfilled PA6 at equivalent stress levels. This makes PA6 CF10 particularly suitable for components subjected to repeated loading, such as gears, brackets, and structural supports. The fatigue behavior is also less sensitive to frequency effects than unfilled nylon, which tends to heat up and fail prematurely under high-frequency cyclic loading.
| 特性 | PA6 CF10 | Unfilled PA6 | PA6 CF30 |
|---|---|---|---|
| 引張強度（MPa） | 100-130 | 60-80 | 150-190 |
| 引張弾性率（GPa） | 6-8 | 2.5-3.0 | 10-14 |
| 曲げ強度（MPa） | 150-180 | 80-100 | 200-250 |
| 破断伸び（%） | 3-5 | 20-30 | 2-3 |
| Notched Izod Impact (kJ/m²) | 4-6 | 6-10 | 7-9 |
| Heat Deflection Temperature (°C at 1.82 MPa) | 180-200 | 65-75 | 200-215 |
Values are typical ranges from commercial datasheets and should be verified with specific material suppliers. Moisture absorption can reduce mechanical properties by 15-25%.
物理的・熱的特性
The physical and thermal characteristics of PA6 CF10 differentiate it from other engineering thermoplastics and influence both processing and in-service performance. Carbon fiber reinforcement improves thermal stability, reduces thermal expansion, and alters the material’s electrical and tribological properties in ways that expand its application envelope.
Thermal Behavior and Dimensional Stability
PA6 CF10 exhibits a melting point of approximately 220-225°C, consistent with the polyamide 6 matrix. The heat deflection temperature (HDT) under 1.82 MPa load increases dramatically from 65-75°C for unfilled PA6 to 180-200°C for PA6 CF10, making the reinforced version suitable for applications near hot components or in elevated-temperature environments. The coefficient of linear thermal expansion (CLTE) is reduced to approximately 2-4 × 10⁻⁵ /°C, roughly half that of unfilled PA6. This improved dimensional stability is critical for precision components that must maintain tight tolerances across temperature variations, such as bearing housings, optical mounts, and electrical connectors. Continuous service temperature ratings typically range from 100-120°C, with short-term excursions possible up to 160-180°C without significant degradation.
Moisture Absorption and Its Effects
Like all polyamides, PA6 CF10 absorbs moisture from the environment, which acts as a plasticizer and affects mechanical properties. At equilibrium, the material absorbs approximately 2-3% moisture at 50% relative humidity and up to 6-7% when immersed in water. This moisture absorption causes dimensional changes—typically 0.5-1.0% linear growth at saturation—and reduces tensile strength and modulus by 15-25% while improving ductility and impact resistance. Engineers must account for these changes when designing components with tight tolerances or press-fit assemblies. For CNC machined parts, moisture conditioning after machining is often recommended to stabilize dimensions before final inspection and assembly. The moisture uptake also affects electrical properties, increasing dielectric constant and dissipation factor, which must be considered for electrical applications.
| 特性 | 値 | 試験規格 |
|---|---|---|
| 密度（g/cm³） | 1.16-1.20 | ISO 1183 |
| 融点（°C） | 220-225 | ISO 11357 |
| ガラス転移温度（℃） | 50-60 (dry) | DSC |
| Heat Deflection Temperature (°C at 0.45 MPa) | 210-220 | ISO 75 |
| Heat Deflection Temperature (°C at 1.82 MPa) | 180-200 | ISO 75 |
| CLTE（×10⁻⁵ /°C） | 2-4 | ISO 11359 |
| Moisture Absorption at 50% RH (%) | 2.0-3.0 | ISO 62 |
| 体積抵抗率（Ω·cm） | 10¹² – 10¹³ | IEC 60093 |
主要な特性と利点
PA6 CF10 offers a unique combination of properties that make it attractive for demanding engineering applications. The material’s advantages stem from the synergistic effects of the polyamide matrix and carbon fiber reinforcement, creating a material that outperforms both unfilled nylon and glass-filled alternatives in specific scenarios.
Comparison with Glass-Filled PA6
When comparing PA6 CF10 to PA6 GF30 (30% glass fiber), the carbon fiber version offers several distinct advantages. Carbon fibers provide higher specific stiffness and strength, allowing for lighter components. The thermal conductivity of carbon fiber (approximately 7-10 W/m·K) is significantly higher than glass fiber (1-2 W/m·K), enabling better heat dissipation in components like gears and bearing cages. Carbon fiber also imparts lower coefficient of friction and better wear characteristics against metal counterparts. However, glass-filled grades are typically less expensive and offer comparable dimensional stability. The choice between CF and GF reinforcement depends on the specific performance requirements, with carbon fiber favored for high-performance applications where weight, thermal management, or tribological performance are critical.
Tribological Performance and Wear Resistance
PA6 CF10 exhibits excellent tribological properties, making it suitable for sliding and wear applications. The carbon fibers act as a solid lubricant at the contact surface, reducing the coefficient of friction against steel from approximately 0.35-0.45 for unfilled PA6 to 0.15-0.25 for PA6 CF10 under dry sliding conditions. The wear rate against hardened steel is reduced by 50-70% compared to unfilled PA6, particularly at moderate PV (pressure-velocity) values. This makes the material ideal for bushings, wear pads, guide rails, and other components where low friction and long service life are required. The material performs well in both dry and lubricated conditions, though the addition of external lubricants can further extend component life. For applications involving abrasive environments or high-speed sliding, additional surface treatments or internal lubricant additives may be considered.
Typical Applications of PA6 CF10
The property profile of PA6 CF10—combining moderate strength, excellent dimensional stability, good wear resistance, and reasonable cost—makes it suitable for a diverse range of applications across multiple industries. Understanding these applications helps engineers identify opportunities where the material can provide performance advantages over alternative materials.
Automotive and Transportation Components
In the automotive sector, PA6 CF10 is used for underhood components that require heat resistance and dimensional stability, such as engine covers, intake manifolds, and sensor housings. The material’s reduced weight compared to metal alternatives contributes to fuel efficiency improvements. Transmission components, including shift forks and selector mechanisms, benefit from the material’s wear resistance and low friction characteristics. The material is also used in pedal assemblies, brake system components, and structural brackets where the combination of stiffness and impact resistance is advantageous. For these applications, PA6 CF10 components are often produced by injection molding, but CNC machining is preferred for low-volume production, prototyping, and custom modifications. The material’s machinability allows for the production of complex geometries with tight tolerances that are difficult to achieve with molding.
Industrial Machinery and Mechanical Components
Industrial applications of PA6 CF10 include gears, pulleys, rollers, and bearing cages where the material’s wear resistance and dimensional stability are critical. The material’s ability to operate without external lubrication in many applications reduces maintenance requirements and eliminates contamination concerns in food processing or cleanroom environments. Conveyor system components, such as wear strips and guide rails, benefit from the material’s low friction and abrasion resistance. In packaging machinery, PA6 CF10 components provide quiet operation and reduced inertia compared to metal parts, enabling higher operating speeds. The material is also used in pump components, valve seats, and seals where chemical resistance to fuels, oils, and solvents is required. For precision applications, CNC machining of PA6 CF10 allows for the production of custom gears and components that meet specific performance requirements without the cost of custom molding tooling.
Electrical and Electronic Applications
While carbon fiber imparts some electrical conductivity to PA6, the material still offers sufficient electrical insulation for many low-voltage applications. PA6 CF10 is used for bobbins, coil formers, and connector housings where dimensional stability and heat resistance are required. The material’s low outgassing characteristics make it suitable for vacuum applications and cleanroom environments. In electrical tools and appliances, PA6 CF10 components provide structural support and electrical insulation in motor housings, switch mechanisms, and brush holders. The material’s ability to dissipate static charge, due to the carbon fiber content, makes it useful for applications where electrostatic discharge protection is required, such as in electronics manufacturing equipment and explosive atmospheres. The volume resistivity of PA6 CF10 typically ranges from 10² to 10⁴ Ω·cm, which is low enough to prevent static accumulation but still provides some electrical insulation compared to metals.
CNC Machining Considerations for PA6 CF10
CNC machining of PA6 CF10 requires specific considerations to achieve optimal results in terms of surface finish, dimensional accuracy, and tool life. The carbon fiber content introduces abrasiveness that affects tool wear, while the material’s thermal properties influence cutting parameters and chip formation. Proper machining practices ensure consistent quality and cost-effective production.
工具選定と切削条件
The abrasive nature of carbon fibers requires the use of carbide or polycrystalline diamond (PCD) tooling for machining PA6 CF10. Standard high-speed steel tools will wear rapidly and produce poor surface finishes. Carbide tools with sharp cutting edges and positive rake angles are suitable for most applications, while PCD tools are recommended for high-volume production where tool life is critical. Recommended cutting speeds range from 100-200 m/min for carbide tools and 300-500 m/min for PCD tools. Feed rates of 0.1-0.3 mm/rev and depths of cut of 0.5-2.0 mm typically produce good results. The material’s low thermal conductivity means that heat generated during cutting remains localized at the cutting zone, requiring effective chip evacuation to prevent heat buildup and surface melting. Coolant use is recommended to control temperature and improve surface finish, though the material can be machined dry with reduced cutting speeds.
Surface Finish and Dimensional Accuracy
PA6 CF10 can achieve excellent surface finishes when machined with sharp tools and appropriate parameters. Surface roughness values of Ra 0.8-1.6 µm are readily achievable, with Ra 0.4 µm possible with fine finishing passes. The carbon fibers can cause slight surface roughness variations compared to unfilled PA6, particularly when machining across the fiber orientation. Dimensional accuracy of ±0.05 mm is achievable in CNC machining, with tighter tolerances of ±0.025 mm possible for critical features. However, the material’s moisture absorption must be considered, as dimensional changes of 0.5-1.0% can occur between dry and moisture-saturated conditions. For precision components, machining should be performed on moisture-conditioned stock, and final dimensions should be verified under controlled humidity conditions. Stress relief may be necessary for parts with complex geometries to prevent warpage after machining.
Chip Control and Part Fixturing
The machining of PA6 CF10 produces short, brittle chips that are easily evacuated from the cutting zone. Unlike unfilled PA6, which produces long, stringy chips that can wrap around tools and workpieces, the carbon fiber content breaks the chips into small fragments. This improves chip management and reduces the risk of chip-related surface damage. However, the abrasive carbon fibers in the chips can cause wear on machine tool ways and guideways if not properly cleaned. Effective chip evacuation systems, including through-tool coolant and vacuum systems, are recommended. Part fixturing must account for the material’s relative softness compared to metals; excessive clamping force can cause deformation, while insufficient force may allow part movement during machining. Soft jaws or vacuum fixturing are often preferred for thin-walled or flexible components. The material’s low thermal expansion coefficient provides good dimensional stability during machining, reducing the risk of thermal distortion.
| 作業工程 | 切削速度（m/min） | 送り速度（mm/回転） | 切り込み深さ（mm） | 工具材料 |
|---|---|---|---|---|
| 粗仕上げ旋削 | 100-150 | 0.2-0.3 | 1.0-2.0 | 超硬合金 |
| 仕上げ旋削 | 150-200 | 0.1-0.15 | 0.3-0.5 | Carbide/PCD |
| Rough Milling | 150-250 | 0.1-0.2 (mm/tooth) | 1.0-2.0 | 超硬合金 |
| Finish Milling | 200-300 | 0.05-0.1 (mm/tooth) | 0.2-0.5 | Carbide/PCD |
| 穴あけ加工 | 50-100 | 0.1-0.2 | — | 超硬合金 |
| タップ加工 | 10-20 | 0.5-1.0 (pitch) | — | 超硬合金 |
Design Guidelines and Best Practices
Successful application of PA6 CF10 in CNC machined components requires adherence to design guidelines that account for the material’s unique characteristics. Proper design practices minimize machining difficulties, reduce production costs, and ensure optimal in-service performance. These guidelines are particularly important for engineers transitioning from metal components to polymer alternatives.
Wall Thickness and Geometric Features
For CNC machined PA6 CF10 components, minimum wall thickness should be 1.0-1.5 mm for small parts and 2.0-3.0 mm for larger components to maintain rigidity and prevent deflection during machining. Unlike injection molding, CNC machining does not have flow length limitations, allowing for thicker sections and more complex geometries. However, thick sections (>10 mm) should be avoided where possible, as they can cause internal stresses and require longer machining times. Internal corners should have a minimum radius of 0.5-1.0 mm to reduce stress concentrations, and draft angles are not required for machined parts. Threaded features should use a minimum thread depth of 1.5 times the thread diameter for adequate strength. For components requiring high precision, such as precision camera parts, the material’s dimensional stability and machinability make it an excellent choice.
Tolerances and Fit Considerations
Standard machining tolerances for PA6 CF10 are typically ±0.05 mm for features up to 50 mm and ±0.1 mm for larger features. Tighter tolerances of ±0.025 mm can be achieved for critical features, but this increases machining cost and requires careful control of environmental conditions. When designing press-fit or interference-fit assemblies, engineers must account for the material’s creep behavior and moisture-related dimensional changes. A typical press-fit allowance for PA6 CF10 is 0.1-0.2% of the shaft diameter, which is lower than for unfilled PA6 due to the fiber reinforcement’s reduced creep. For components that will be exposed to moisture, the design should account for the 0.5-1.0% dimensional growth at saturation. Sliding fits should provide adequate clearance to accommodate moisture absorption and thermal expansion, particularly in applications where the component will be exposed to temperature variations.
Post-Machining Treatment and Quality Control
After CNC machining, PA6 CF10 components may require post-machining treatments to optimize performance. Deburring is essential to remove sharp edges that can initiate cracks, particularly given the material’s reduced ductility. For components that will see cyclic loading, polishing the machined surfaces can improve fatigue life by removing machining marks that act as stress concentrators. Moisture conditioning, by exposing the machined parts to a controlled humidity environment, stabilizes dimensions before final inspection. Quality control should include dimensional verification under controlled temperature and humidity conditions, as well as visual inspection for surface defects. For critical applications, non-destructive testing methods such as ultrasonic inspection may be employed to detect internal voids or delamination. The material’s consistent machinability allows for reliable quality control processes, making it suitable for precision mounting blocks and other applications requiring repeatable accuracy.
Advantages and Limitations in CNC Machining
Understanding the comparative advantages and limitations of PA6 CF10 relative to other machinable materials helps engineers make informed material selection decisions. This section provides a balanced assessment of where the material excels and where alternative materials may be more appropriate.
Advantages Over Metals and Unfilled Polymers
PA6 CF10 offers significant weight reduction compared to aluminum and steel components, with density approximately 1.16-1.20 g/cm³ versus 2.7 g/cm³ for aluminum and 7.8 g/cm³ for steel. This weight reduction translates to lower inertia in moving parts, reduced energy consumption in transportation applications, and easier handling during assembly. The material’s corrosion resistance eliminates the need for surface treatments such as anodizing or plating, reducing production costs and environmental impact. Unlike unfilled PA6, PA6 CF10 provides the stiffness and dimensional stability required for precision applications, making it suitable for components that would previously require metal fabrication. The material’s excellent wear resistance and low coefficient of friction often eliminate the need for separate bearing or bushing components, simplifying designs and reducing part counts. The machinability of PA6 CF10 is superior to most metals, with faster cutting speeds, longer tool life, and no need for cutting fluids in many applications.
Limitations and Material Selection Considerations
PA6 CF10 has several limitations that engineers must consider. The material’s maximum continuous service temperature of approximately 100-120°C is significantly lower than metals, restricting its use in high-temperature environments. The moisture absorption of the material can cause dimensional changes and property variations that must be managed through design and conditioning. The reduced ductility compared to unfilled PA6 makes the material more susceptible to impact damage and stress cracking. The electrical conductivity imparted by carbon fibers may be undesirable for certain electrical insulation applications. The material’s cost is higher than unfilled PA6 and glass-filled grades, though lower than many high-performance engineering polymers. For applications requiring very high strength or stiffness, alternative materials such as PA6 CF30 or metal components may be more appropriate. For applications requiring extreme wear resistance, materials like Ultem for precision CNC applications may offer better performance, albeit at higher cost.
Tuofa CNC: Precision Machining of PA6 CF10 Components
Tuofa CNC, operating as Tuofa CNC Germany, specializes in precision CNC machining of engineering thermoplastics including PA6 CF10. With advanced 3-axis and 5-axis CNC machining centers, Tuofa CNC delivers components that meet the most demanding tolerance and surface finish requirements. The company’s expertise in polymer machining ensures optimal cutting parameters, tool selection, and quality control processes for PA6 CF10 parts.
Capabilities and Equipment for Polymer Machining
Tuofa CNC’s machining facility is equipped with state-of-the-art CNC lathes and milling machines capable of holding tolerances of ±0.01 mm on critical features. The company maintains a comprehensive inventory of carbide and PCD tooling specifically selected for machining carbon fiber reinforced polymers. Advanced coolant systems and chip evacuation equipment ensure consistent machining conditions and prevent heat-related defects. Tuofa CNC’s quality control department utilizes coordinate measuring machines (CMM) and optical measurement systems to verify dimensional accuracy, with inspection reports provided with every shipment. The company’s engineering team provides design for manufacturability (DFM) feedback to help customers optimize their PA6 CF10 components for cost-effective production. For applications requiring specialized features, Tuofa CNC offers a range of secondary operations including threading, tapping, and surface finishing.
Applications and Quality Assurance
Tuofa CNC has extensive experience machining PA6 CF10 components for diverse industries including automotive, industrial machinery, electronics, and medical devices. The company’s quality management system is certified to ISO 9001:2015, ensuring consistent quality across all production runs. Every PA6 CF10 component undergoes rigorous inspection, including dimensional verification, surface finish assessment, and visual inspection for defects. Tuofa CNC provides material certifications and traceability documentation, ensuring that customers receive components manufactured from verified PA6 CF10 material. The company’s commitment to quality and precision makes it a trusted partner for companies requiring reliable, high-performance polymer components. Whether producing prototypes, low-volume production runs, or high-volume quantities, Tuofa CNC delivers PA6 CF10 components that meet or exceed customer specifications. The company’s expertise extends to related materials and applications, including 精密端子台 and other engineered components requiring tight tolerances and consistent quality.
結論
PA6 CF10 represents a versatile engineering thermoplastic that combines the toughness and chemical resistance of polyamide 6 with the stiffness and dimensional stability provided by 10% carbon fiber reinforcement. Its balanced property profile—moderate strength, excellent wear resistance, improved heat deflection temperature, and good machinability—makes it suitable for a wide range of CNC machined components across automotive, industrial, and electronic applications. While the material has limitations in terms of moisture absorption and reduced ductility, proper design and machining practices mitigate these concerns. For engineers seeking a cost-effective alternative to metals or unfilled polymers, PA6 CF10 offers an attractive combination of performance and manufacturability. With the expertise of precision machining partners like Tuofa CNC, components manufactured from PA6 CF10 deliver reliable performance in demanding applications.