1607 An Innovative Cutting Method for CFRP to Realize a Defect-free Machining Without Any Feedback Control Systems
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | Proceedings of International Conference on Leading Edge Manufacturing in 21st century LEM21 |
| Authors | Yasuo Kondo, Yuki Doi, Takafumi Adachi, Satoshi Sakamoto, Kenji Yamaguchi |
| Institutions | Yokohama National University, Yamagata University |
| Analysis | Full AI Review Included |
Technical Analysis: MPCVD Diamond for Defect-Free CFRP Machining
Section titled âTechnical Analysis: MPCVD Diamond for Defect-Free CFRP MachiningâThis document analyzes the research on Constant Load Feeding (CLF) for defect-free machining of Carbon Fiber Reinforced Plastics (CFRP) and outlines how 6CCVDâs specialized MPCVD diamond materials provide the necessary tool performance to maximize the efficiency and quality of this innovative method.
Executive Summary
Section titled âExecutive SummaryâThe research validates an innovative Constant Load Feeding (CLF) method for high-precision, defect-free secondary working of CFRP, relying heavily on superior tool material properties.
- Core Achievement: CLF self-regulates the tool feed rate, maintaining a constant, minimized cutting resistance throughout the process.
- Defect Elimination: By stabilizing cutting resistance, CLF prevents the steep temperature rise that causes epoxy softening (70-80 °C) and subsequent delamination/scuffing in CFRP.
- Tool Material Criticality: The study confirms that high-hardness materials (Cemented Carbide and Diamond) are essential, as they significantly outperform High Speed Steel (HSS) in minimizing cutting resistance and specific power consumption.
- 6CCVD Value Proposition: To fully realize the potential of CLF for industrial application, the highest quality tool materials are required. 6CCVD provides custom Polycrystalline Diamond (PCD) and Single Crystal Diamond (SCD) plates for fabricating ultra-hard, wear-resistant cutting tools (drills, blades, face mills).
- Performance Metrics: Drilling with superior tools under CLF resulted in a temperature rise of only ~10 °C, significantly reducing damage compared to Constant Rate Feeding (CRF).
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental conditions and results:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| CFRP Thickness | 4 | mm | Thermosetting Carbon/epoxy (Vf=0.6) |
| Diamond Saw Blade Thickness | 0.7 | mm | Tool dimension |
| Diamond Saw Grit | #150 | - | Tool specification |
| Diamond Saw Peripheral Speed | 3.33 | m/min | Cutting condition |
| CLF Load (Sawing) | 0.5 | N | Applied load (P) |
| CLF Load (Drilling Thrust Force) | 18 | N | Minimum force required to generate a hole |
| Drilling Spindle Speed | 1250 | rpm | Dry condition |
| Critical Epoxy Softening Temperature | 70 - 80 | °C | Temperature threshold for delamination |
| CLF Temperature Rise (Drilling) | ~10 | °C | Temperature rise above baseline (defect-free) |
| CRF Cutting Resistance (Peak) | Up to 50 | W | High resistance, high damage (1.2 mm/min rate) |
| CC Drill Specific Power (CLF) | ~200 | W·s/cm³ | Minimized power consumption |
| HSS Drill Specific Power (CRF) | 5200 | W·s/cm³ | Maximum power consumption (1.2 mm/min rate) |
Key Methodologies
Section titled âKey MethodologiesâThe experiment focused on comparing Constant Load Feeding (CLF) against traditional Constant Rate Feeding (CRF) using various tool materials for sawing and drilling CFRP laminates.
- Material Structure: CFRP laminate (4mm thick) composed of two sections of [0°/90°] cross-ply lamination (7 piles each), bonded by a plane weave cloth sheet.
- Sawing Tool: General-purpose precise cutter equipped with a diamond blade saw (#150 grit, 0.7mm thickness).
- Drilling Tools: Commercial 4.0mm diameter drills (High Speed Steel (HSS) and Cemented Carbide (CC)).
- Constant Load Feeding (CLF): Mechanism applies a fixed, small load (0.5 N for sawing, 18 N thrust for drilling), allowing the tool to self-generate the optimal feed rate based on cutting resistance.
- Constant Rate Feeding (CRF): Mechanism feeds the CFRP at fixed rates (e.g., 0.3, 1.3 mm/min for sawing; 1.2, 14, 20 mm/min for drilling).
- Measurement & Analysis: Cutting force, effective power, and CFRP temperature rise were monitored. Cutting damage (chipping, scuffing, delamination) was assessed using an optical microscope.
- Key Finding on Tool Wear: HSS drills showed significant chisel wear after only 2 holes under CLF, emphasizing the necessity of ultra-hard materials like Cemented Carbide or Diamond for sustained operation.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research explicitly calls for a âmulti-fold approachâ requiring optimized tool material to achieve defect-free machining without complex feedback systems. 6CCVD provides the advanced MPCVD diamond materials necessary to manufacture these next-generation tools.
Applicable Materials for CFRP Machining
Section titled âApplicable Materials for CFRP MachiningâThe Constant Load Feeding method demands tools with extreme hardness, high thermal conductivity, and minimal wear to maintain a stable, low cutting resistance.
| 6CCVD Material | Application Focus | Key Benefit for CLF Machining |
|---|---|---|
| Polycrystalline Diamond (PCD) | Saw blades, drill inserts, face mill tips, wear parts. | Superior toughness and abrasion resistance; ideal for high-volume CFRP processing where tool life is critical. Available in large formats (up to 125mm). |
| Single Crystal Diamond (SCD) | Ultra-precision micro-drills, specialized cutting edges. | Highest hardness and lowest friction coefficient (Ra < 1nm achievable). Minimizes cutting resistance and heat generation for the most sensitive CFRP components. |
| Boron-Doped Diamond (BDD) | Electrochemical sensing, specialized coatings. | While not primary for cutting, BDD coatings can be explored for specialized tool surface treatments requiring specific electrical properties. |
Customization Potential for Tool Fabrication
Section titled âCustomization Potential for Tool Fabricationâ6CCVDâs capabilities directly support the manufacturing requirements for high-performance CFRP cutting tools:
- Custom Dimensions: We supply PCD and SCD plates/wafers in custom sizes up to 125mm diameter, allowing manufacturers to design large-format saw blades or complex face mill geometries.
- Thickness Control: SCD and PCD materials are available from 0.1 ”m (for thin film coatings) up to 500 ”m (for robust tool inserts), ensuring optimal material volume for specific tool geometries (e.g., 4.0mm diameter drills or 0.7mm thick blades).
- Precision Polishing: 6CCVD offers polishing services to achieve surface roughness (Ra) < 1nm for SCD and < 5nm for inch-size PCD. This ultra-smooth finish is crucial for minimizing friction and cutting resistance, directly supporting the CLF mechanismâs goal of maintaining constant, low force.
- Metalization Services: We offer in-house metalization (Au, Pt, Pd, Ti, W, Cu) for bonding diamond inserts to tool bodies (e.g., cemented carbide shanks), ensuring robust mechanical and thermal interfaces.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in the material science of CVD diamond. We can assist engineers and researchers in selecting the optimal diamond grade (e.g., specific PCD grain size or SCD orientation) to maximize tool life and minimize cutting resistance for similar CFRP Machining projects utilizing Constant Load Feeding systems.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
An innovative cutting method, Constant Load Feeding Method, is proposed to as a high precision secondary working tool in CFRP cutting. The constant load feeding of CFRP can restrain the occurrence of cutting defects such as burr and scuffing in a diamond saw cutting. In addition, there was no apparent cutting damage on the cutting surface obtained from the drilling with Constant Load Feeding. The cutting resistance has been kept a constant value over the whole process. Namely, the Constant Load Feeding can self-generate the optimal feed rate of drill to realize a defect-free drilling of CFRP composites without any feedback control systems based on the cutting force.