PCBN tools experience both normal and abnormal wear during use. The primary forms of normal wear in PCBN tools include oxidation wear, phase transformation wear, friction wear, adhesion wear, micro-chipping wear, and spalling wear, among others. These various wear factors interact and reinforce one another. The primary factors contributing to abnormal wear of PCBN tools include improper selection of cutting parameters and tool geometry, as well as insufficient rigidity of the machining system. To extend the service life of PCBN tools, the following specific measures can be implemented to address common wear forms and damage phenomena observed in actual use:
1) Rear face wear
Improvement measures: ① Increase the cutting line speed;
② Increase the workpiece feed rate;
③ Increase the cutting depth;
④ Check whether the cutting point of the insert is located at the center height;
⑤ If the workpiece material is cast iron, check whether the ferrite content is within the controlled range.
6) Severe chipping of the cutting edge
Improvement measures:
① Reduce the cutting depth or machining allowance to lower the cutting load;
② Reduce the cutting speed;
③ Appropriately increase the radius of the tool tip (or even use a round tool);
④ Use tools with a chamfered or ground cutting edge;
⑤ Check whether the tool is installed correctly and securely, and whether the mounting surface is intact (especially for solid CBN tools);
⑥ Check whether the center height of the tool's cutting edge is correct.
