How To Prevent Wear On CBN Inserts

The core causes of CBN inserts wear:

  1. Chemical wear: material reaction at high temperatures.

  2. Mechanical wear: abrasive cutting and impact spalling of hard phases

  3. Improper machining process: unreasonable parameters, insufficient cooling, etc.

  4. Thermochemical wear: high temperatures lead to decreased hardness & accelerated chemical wear.         

CBN inserts wear causes & solutions:

1. Flank Wear 

Cause: Incorrect cutting speed

Solution: Reduce cutting speed, select a more wear-resistant grade, and use the correct cooling method.

2. Crater Wear                   

Cause: Incorrect cutting speed

Solution: Use coated inserts, use cutting fluid, reduce chip interference and heat, and reduce cutting speed and feed rate.

3. Edge Breakage        

Cause: Incorrect tool use

Solution: Reduce feed rate and depth of cut, and use chip breaker inserts.

4. Built-up Edge                                                                                             

Cause: Formed when workpiece fragments are thermo-welded to the cutting edge.

Solution: Increase cutting speed and feed rate, select sharper insert flutes and smoother rake faces, use proper cutting fluid or increase cutting fluid concentration.

5. Groove Wear                                                                         

Cause: Formed when the workpiece surface is harder or more abrasive than its underlying material

Solution: Reduce feed rate, use chip breaker inserts.

6. Chipping Wear    

Cause: Caused by mechanical instability or cracks in the cutting material.

Solution: Ensure good machine tool accuracy, reduce feed rate, increase cutting speed.