Common wear forms of PCBN tools and improvement measures

PCBN tools will have normal wear and abnormal wear during use. The normal wear forms of PCBN tools mainly include oxidation wear, phase change wear, friction wear, adhesive wear, micro-chipping wear, peeling wear, etc., and various wear factors affect and promote each other. The main influencing factors of abnormal wear of PCBN tools are improper selection of cutting amount and geometric parameters of inserts, and insufficient rigidity of processing system. In order to improve the service life of PCBN tools, the following specific measures can be taken to improve the common wear patterns and damage phenomena of PCBN tools in actual use:

1. Flank wear

Improvement measures: ①Increase the cutting line speed; ②Increase the workpiece feed rate; ③Increase the depth of cut; ④Check whether the cutting point of the blade is located at a high center; is within the control range.

2. crater wear

Improvement measures: ① reduce the cutting speed; ② reduce the workpiece feed rate.

3. Cutting hammer

Improvement measures: ①Increase the cutting speed; ②Reduce the cutting feed rate; ③Improve the cutting rake angle of the tool (such as using a round blade, etc.).

4. Cutting edge chipping

Improvement measures: ① Use a blade with a chamfered or ground edge; ② Reduce the cutting speed or avoid interrupted cutting as much as possible; ③ Improve the rigidity of the process system; ④ If intermittent cutting is unavoidable (such as holes, grooves, etc. on the machined surface), the corresponding cutting entry parts should be pre-chamfered; ⑤ Change the cutting line speed to optimize the cutting conditions and avoid vibration.

5. The rake face of the insert is peeled off during milling

Improvement measures: ① Reduce the cutting angle of the tool (preferably less than 20°); ② Use up-cut milling as much as possible; ③ Avoid Use coolant; ④ increase the cutting speed.

6. Severe edge chipping

Improvement measures: ①Reduce the cutting depth or machining allowance to reduce the cutting load; ②Reduce the cutting speed; ③Appropriately increase the corner radius of the tool nose (even a round blade can be used); ④ Use a blade with a reversed edge or a ground edge; ⑤ Check whether the blade is installed correctly and reliably, and whether the installation surface is in good condition (especially the overall CBN blade); ⑥ Check whether the center of the cutting edge of the blade is high correct.

The success of the use of PCBN tools depends not only on the quality of the tool itself, but also on all aspects of the entire processing system, such as the performance of the machine tool, the reliability of workpiece clamping, and the rigidity of the toolholder system. , The rationality of blade selection, the selection of cutting parameters, etc. will affect the cutting effect of PCBN tools. Only the correct and reasonable use of PCBN tools can improve processing efficiency, reduce production costs, and obtain the greatest technical and economic benefits.