Machining cemented carbide molds is a precision and complex process that requires attention to the following aspects:

1. Material Characteristics

• High hardness and high brittleness: Cemented carbide is extremely hard but also very brittle, making it prone to cracking or edge chipping during machining. Therefore, excessive impact forces or stress concentrations must be avoided.

• High wear resistance: Cemented carbide has excellent wear resistance, which also means that cutting tools (such as inserts and grinding wheels) need to have even higher hardness and wear resistance.

2. Machining Equipment

• High‑rigidity machine tools: Machining cemented carbide requires high‑rigidity, high‑precision machine tools to minimize vibration and deformation.

• High‑speed spindles: Cemented carbide machining typically demands relatively high cutting speeds, so the spindle should have high‑speed capability.

• Cooling system: A large amount of heat is generated during processing; an efficient cooling system (e.g., oil‑based or air‑cooled) is necessary to prevent overheating of both the workpiece and the tool.

3. Tool Selection

• Tool materials: Diamond (PCD) or cubic boron nitride (CBN) tools are commonly used because their hardness is sufficient to machine cemented carbide.

• Tool geometry: The rake angle, clearance angle, and edge design must be optimized to reduce cutting forces and avoid chipping.

• Tool wear monitoring: Tool wear occurs relatively quickly in cemented carbide machining, so regular inspections and timely replacement are required.

4. Machining Process

• Cutting parameter optimization: Cutting speed, feed rate, and depth of cut should be optimized based on the specific material and tool. Generally, higher cutting speeds with smaller feed rates are adopted.

• Layered/step machining: For molds with complex shapes, a layered machining strategy is recommended to reduce the load per pass and prevent tool breakage or workpiece damage.

• Vibration avoidance: Vibrations must be minimized during machining, as they degrade surface quality and accelerate tool wear.

5. Surface Finishing

• Polishing and lapping: After machining, cemented carbide molds usually require polishing or lapping to improve surface smoothness and dimensional accuracy. Diamond grinding wheels or lapping pastes can be used for fine finishing.

• Coating treatment: If required, the mold surface can be coated (e.g., with TiN, TiAlN, etc.) to enhance wear resistance and service life.

6. Quality Control

• Dimensional accuracy: Cemented carbide molds demand extremely high dimensional accuracy. High‑precision measuring instruments (e.g., coordinate measuring machines) should be used for real‑time monitoring during machining.

• Surface quality: After machining, the surface must be inspected for cracks, edge chipping, and other defects to ensure it meets the required quality standards.

7. Safety Precautions

• Protective measures: Fine particles are generated during cemented carbide machining; operators should wear protective goggles and masks to avoid inhaling dust.

• Waste disposal: Cemented carbide scrap is often very sharp and must be handled properly to prevent cuts.

8. Post‑Processing

• Stress relief: After machining, it is advisable to perform stress‑relief treatment (e.g., low‑temperature tempering) to reduce residual stresses and prevent deformation or cracking of the mold during subsequent use.

In summary, machining cemented carbide molds requires comprehensive consideration of material characteristics, equipment capabilities, tool selection, processing techniques, and quality control to ensure an efficient and stable process, ultimately producing high‑quality mold products.