Custom Carbide Inserts Manufacturing Service

Key Aspects of Carbide Insert Design

1. Geometry:
   
   • Shape: Inserts come in various shapes (e.g., triangular, square, round, diamond, or rhombic), each suited for specific applications. For example:
     
     • Round inserts: Ideal for high-feed milling or contouring.
     • Square inserts: Used for general-purpose milling or turning with strong cutting edges.
     • Triangular inserts: Common for turning, offering versatility with multiple cutting edges.
   • Rake Angle: The angle of the cutting face affects chip formation and cutting forces. Positive rake angles reduce cutting forces and are used for softer materials, while negative rake angles provide stronger edges for harder materials or heavy cuts.
   • Clearance Angle: The angle between the insert’s flank and the workpiece prevents rubbing and ensures smooth cutting. Typically 5°–15°, depending on the application.
   • Nose Radius: The rounded tip of the insert impacts surface finish and strength. Smaller radii are used for precision and light cuts, while larger radii handle heavier cuts but may increase vibration.
2. Chip Breaker Design:
   
   • Chip breakers are grooves or features on the insert’s top surface that control chip formation, directing chips away from the workpiece to prevent damage and improve safety. Designs vary based on material and cutting conditions:
     
     • Light-duty chip breakers: For low-feed rates and soft materials.
     • Heavy-duty chip breakers: For high-feed rates and tougher materials like stainless steel.
     • Chip breaker geometry is tailored to specific feeds, depths of cut, and material types (e.g., steel, aluminum, or titanium).
3. Material and Coating:
   
   • Base Material: Tungsten carbide provides the core hardness, with cobalt (typically 6–12%) enhancing toughness. The carbide grain size (submicron to coarse) influences hardness and toughness trade-offs.
   • Coatings: Applied via techniques like Chemical Vapor Deposition (CVD) or Physical Vapor Deposition (PVD), coatings enhance wear resistance and reduce friction. Common coatings include:
     
     • Titanium Nitride (TiN): General-purpose, wear-resistant.
     • Titanium Carbonitride (TiCN): For high-speed cutting.
     • Aluminum Oxide (Al2O3): For high-temperature applications.
     • Diamond-like coatings: For non-ferrous materials like aluminum.
   • Multi-layer coatings combine properties for versatility across materials and conditions.
4. Mounting and Clamping Features:
   
   • Inserts are designed with holes, chamfers, or countersinks for secure mounting on tool holders. Common mounting styles include:
     
     • Screw-on: A central hole for screw attachment.
     • Clamp-on: Held by a clamp without a hole, often for negative rake inserts.
   • The insert’s base geometry (flat or with locating features) ensures precise positioning and stability during cutting.
5. Edge Preparation:
   
   • Cutting edges may be honed (slightly rounded) or chamfered to increase edge strength and prevent chipping, especially for interrupted cuts or hard materials.
   • Sharp edges are used for soft materials or finishing operations to minimize cutting forces and improve surface finish.
6. Insert Size and Thickness:
   
   • Inserts are sized based on the inscribed circle (IC) diameter or edge length, affecting cutting depth and stability. For example, a larger IC (e.g., 12 mm) is used for heavy machining.
   • Thickness impacts rigidity, with thicker inserts suited for high-force applications.

Design Standards and Coding

• ISO/ANSI Standards: Inserts are standardized (e.g., ISO 1832) with a code system describing shape, size, tolerance, and features. For example, a code like CNMG 120408 indicates:
  
  • C: Shape (rhombic, 80°).
  • N: Clearance angle (0°, neutral).
  • M: Tolerance class.
  • G: Chip breaker and mounting style.
  • 12: IC size (12 mm).
  • 04: Thickness (4 mm).
  • 08: Nose radius (0.8 mm).
• These codes help machinists select inserts for specific tools, materials, and operations.

Applications and Design Considerations

• Material-Specific Designs: Inserts are optimized for materials like steel, cast iron, aluminum, or superalloys. For example:
  
  • Aluminum requires sharp edges and polished surfaces to prevent material buildup.
  • Hardened steels need tough inserts with negative rake angles and robust coatings.
• Cutting Conditions: Designs account for speed, feed rate, and depth of cut. High-speed machining may use PVD-coated inserts, while heavy roughing uses thicker, CVD-coated inserts.
• Sustainability: Modern designs focus on multi-edge inserts (e.g., triangular inserts with six usable edges) to reduce waste and cost.