In the field of precision machining, cutting hard and brittle materials like glass, ceramics, and composites presents a significant challenge. Traditional metal or carbide scribing wheels often suffer from rapid wear and short lifespans, making it difficult to meet the demands for high efficiency and consistency.
In recent years, PCD (Polycrystalline Diamond) Scribing Wheels have emerged as the preferred tool for these applications due to their superior performance.
What is a PCD Scribing Wheel?
A PCD scribing wheel is a disc-shaped cutting tool featuring a Polycrystalline Diamond composite layer sintered or embedded onto a tungsten carbide substrate.
Composition: Formed by sintering micron-sized diamond particles under high temperature and high pressure.
Hardness: It boasts a hardness close to natural diamond (HV 8000–10000), combined with exceptional wear resistance and impact strength.
Mechanism: The edge is precision-ground to form a sharp, stable cutting point. In high-speed operation, it utilizes a "micro-crack guidance" mechanism to scribe or fully cut brittle materials with extreme precision.
Application Materials
PCD scribing wheels are specifically engineered for non-metallic, hard, and brittle materials:
Glass: Soda-lime glass, Borosilicate glass, Chemically toughened glass (e.g., smartphone cover glass), and LCD/OLED display substrates.
Ceramics: Alumina (Al2O3), Aluminum Nitride (AlN), Piezoelectric ceramics, and Structural ceramics.
Composites: Carbon Fiber Reinforced Plastics (CFRP) and Glass Fiber Reinforced Plastics (GFRP).
Others: Quartz, Sapphire, and certain Semiconductor wafer processes.
Important Note: PCD wheels are NOT suitable for metals containing Iron (Ferrous materials like Steel or Cast Iron). At high cutting temperatures, diamond reacts chemically with iron, leading to rapid tool failure.
Selection Guide: How to Choose the Right PCD Wheel
To achieve the best cutting results, four key factors must be considered:
1. Material Type and Thickness
Thin Glass (< 1 mm): Select a small diameter (e.g., Φ2–Φ4 mm) wheel with a narrow edge width to ensure high scribing precision.
Thick Glass or Ceramics (> 3 mm): Requires a larger diameter (Φ6–Φ10 mm) and a high-strength substrate to withstand the greater cutting forces required.
2. Edge Geometry (Cutting Angle)
Common geometries include Flat, Cone (e.g., 120°, 140°), and Radius edges.
Large Cone Angle: Creates a shallower cut depth. Ideal for thin, brittle materials to prevent breakage.
Small Cone Angle: Provides stronger penetration for deeper cuts but increases the risk of edge chipping.
3. PCD Layer Thickness and Grain Size
Coarse Grain (25–50 μm): Offers superior wear resistance. Best for rough cutting or applications requiring maximum tool life.
Fine Grain (2–10 μm): Provides a sharper edge. Best for high-precision cutting where surface finish quality is critical.
4. Installation and Interface
Ensure the wheel's Bore Diameter (ID) and Flange dimensions match your equipment (e.g., CNC glass cutting machines or laser-assisted scribing machines). Check if a positioning slot is required.
Operational Tips for Best Performance
Lubrication: We recommend MQL (Minimum Quantity Lubrication) or Dry Running. Avoid water-based cooling that causes thermal shock.
Wear Monitoring: Regularly inspect the edge. Even slight dulling can alter the crack propagation path, leading to poor breaking quality or scrap parts.
Parameter Optimization: For chemically strengthened glass, strictly optimize the scribing pressure and speed to prevent stress concentration from causing unintended fractures.
Conclusion
With their ultra-high hardness, wear resistance, and extended service life, PCD Scribing Wheels have become the core tooling solution for the modern electronics, optoelectronics, and new energy industries. By understanding their working principles and selecting the right specifications, manufacturers can significantly improve cutting yield and reduce per-unit processing costs.
Looking for high-precision PCD Scribing Wheels? Contact us today to discuss your specific cutting requirements.
