What Are the Design Considerations for Cermet Turning Inserts

Cermets, also known as ceramic-metal composites, are widely used in the cutting tool industry due to their excellent wear resistance and high-temperature performance. When it comes to cermet turning inserts, there are several design considerations that need to be taken into account to ensure optimal performance and cutting efficiency.

Insert Geometry: The geometry of the cermet turning insert plays a crucial role in its performance. One of the key considerations is the shape of the cutting edge. The choice between a positive or negative rake angle depends on the material being cut and the desired cutting forces. In general, a positive rake angle provides better chip control and reduces cutting forces, while a negative rake angle is preferred for harder materials that require higher cutting forces.

Coating: Coating the cermet turning insert with a thin layer of coating material can further enhance its performance. The choice of coating depends on the application and the material being cut. Common coating materials include titanium nitride (TiN), titanium carbonitride (TiCN), aluminum oxide (Al2O3), and diamond-like carbon (DLC). The coating helps to reduce friction and heat generation, which in turn prolongs the tool life and improves cutting performance.

Chip Breakers: The presence of chip breakers on the cermet turning insert is crucial for effective chip control. Chip breakers are small grooves or cutouts on the cutting edge that help to break the chips into smaller, more manageable sizes. This prevents the chips from getting entangled in the cutting tool or causing damage to the workpiece. The design and placement of chip breakers depend on factors such as the material being cut, the feed rate, and the cutting depth.

Edge Preparation: Proper edge preparation is essential for reducing cutting forces and improving tool life. The edges of cermet turning inserts should be carefully honed or ground to ensure sharpness and precision. Edge preparations such as chamfering, honing, or rounding can also help to improve chip flow and reduce cutting temperature.

Insert Grade: The selection of the appropriate insert grade for a cermet turning insert depends on the specific application and the material being cut. Different grades offer varying levels of wear resistance, toughness, and heat resistance. It is important to consider the cutting speed, depth of cut, and feed rate when choosing the right insert grade to ensure optimal performance.

In conclusion, the design considerations for cermet turning inserts include insert geometry, coating, chip breakers, edge preparation, and insert grade. By carefully considering these factors, manufacturers can optimize cutting performance, achieve longer tool life, and minimize machining costs.