Why does the carbide blade chip？_2

Causes and countermeasures for chipping of cemented carbide Inserts:

1. Inappropriate selection of blade grades and specifications, such as the thickness of the Inserts is too thin or the grades that are too hard and brittle are selected for rough machining.

Countermeasures: increase the thickness of the blade or install the blade in a vertical position, and choose a grade with higher bending strength and toughness.

2. Improper selection of tool geometry parameters (for example, the front and rear angles are too large, etc.).

Countermeasures: The tool can be redesigned from the following aspects. ①Appropriately reduce the front and rear angles; ②Using a larger negative blade inclination; ③Reducing the entering angle; ④Using a larger negative chamfer or cutting edge arc; ⑤Grinding the transition cutting edge to enhance the tip.

3. The welding process of the blade is incorrect, causing excessive welding stress or welding cracks.

Countermeasures: ①Avoid using a three-sided closed blade slot structure; ②Select solder correctly; ③Avoid using oxyacetylene flame heating welding, and heat preservation after welding to eliminate internal stress; ④Use a mechanical clamping structure as much Carbide Aluminum Inserts as possible

Tungsten carbide blade

4. Improper sharpening methods will cause grinding stress and grinding cracks; excessive vibration of the teeth after sharpening PCBN milling cutters will cause too much load on individual teeth, which will also cause tool hitting.

Countermeasures: ①Use intermittent grinding or diamond wheel grinding; ②Select a softer wheel, and often dress to keep the wheel sharp; ③Pay attention to the quality of sharpening, and strictly control the amount of vibration of the cutter teeth.

 5. The selection of cutting amount is unreasonable. If the amount is too large, the machine will become stuffy; when intermittent cutting, the cutting speed is too high, the feed rate is too large, and the blank margin is uneven, the cutting depth tungsten carbide inserts is too small; cutting high manganese steel For materials with high work hardening tendency, the feed rate is too small, etc.

Countermeasure: Reselect the cutting amount.

6. Structural reasons such as the uneven bottom surface of the knife groove of the mechanical clamping tool or the excessively extended blade.

Countermeasures: ① trim the bottom surface of the tool groove; ② reasonably arrange the position of the cutting fluid nozzle; ③ add a hard alloy gasket under the blade of the hardened tool bar.

7. Excessive tool wear.

Countermeasures: Change the tool or the cutting edge in time.

8. The cutting fluid flow is insufficient or the filling method is incorrect, causing the blade to burst and crack.

Countermeasures: ① Increase the flow of cutting fluid; ② Reasonably arrange the position of the cutting fluid nozzle; ③ Use effective cooling methods such as spray cooling to improve the cooling effect.

9. The tool is not installed correctly, such as: the cutting tool is installed too high or too low; the face milling cutter uses asymmetric down milling, etc.

Countermeasure: Reinstall the tool.

10. The rigidity of the process system is too poor, resulting in excessive cutting vibration.

Countermeasures: ①Increase the auxiliary support of the workpiece to improve the rigidity of the workpiece clamping; ②Reduce the overhang of the tool; ③Appropriately reduce the clearance angle of the tool; ④Use other anti-vibration measures.

11. Inadvertent operation, such as: when the tool cuts in from the middle of the workpiece, the action is too violent; the tool has not been withdrawn, and it stops immediately.

Countermeasure: Pay attention to the operation method.

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