Characteristics
- High Hardness and Wear Resistance: Quenched steel typically has a hardness above HRC50, so the milling cutter material must have even higher hardness and wear resistance to effectively cut without wear.
- Good Heat Resistance: A significant amount of heat is generated during the cutting process, and the cutter material needs to maintain high hardness at high temperatures, i.e., it should have good thermal hardness.
- High Strength and Toughness: Due to the high cutting forces, the cutter material must have high strength and toughness to withstand the impact and vibration during cutting.
- Resistance to Built-Up Edge: Since quenched steel is hard and brittle, it is less likely to form built-up edges during cutting, resulting in lower surface roughness.
Process Requirements
- Cutter Material Selection: Common materials include hard alloys (such as fine-grained or ultra-fine-grained hard alloys with TaC or NbC additions), ceramics, and polycrystalline cubic boron nitride (PCBN). These materials offer high hardness, high wear resistance, and good heat resistance.
- Cutter Geometric Parameters: To improve cutting conditions and increase the surface area for heat dissipation, smaller rake angles and clearance angles are typically chosen.
- Cutting Parameters: High-speed milling technology can improve processing efficiency and surface quality, reducing processing time. Specific cutting speeds, feed rates, and cutting depths need to be optimized based on the processing conditions and cutter material.
- Cooling and Lubrication: Due to the high cutting temperatures, effective cooling and lubrication measures are necessary to reduce cutting temperatures and extend tool life.
