Causes and countermeasures for chipping of cemented carbide tools:
1) The blade grades and specifications are improperly selected, Cemented Carbide Inserts such as the blade thickness is too thin or the blade is too hard and brittle when roughing.
Countermeasures: Increase the thickness of the blade or install the blade vertically, and choose a grade with higher bending strength and toughness.
2) Improper selection of tool geometry parameters (such as excessive front and rear angles, 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 tool tip.
3) The welding process of the blade is incorrect, causing excessive welding stress or welding cracks.
Countermeasures: ①Avoid using three-sided closed blade slot structure; ②Select solder correctly; ③Avoid using oxyacetylene flame heating and welding, and keep heat preservation after welding to eliminate internal stress; ④Use mechanical clamping structure as much as possible
4) Improper sharpening methods can cause grinding stress and grinding cracks; excessive vibration of the teeth after sharpening PCBN milling cutters will cause excessive load on individual teeth and 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 oscillation 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 is too small; cutting high manganese steel For materials with high work hardening tendency, the feed rate is too small.
Countermeasure: Reselect the cutting amount.
6) Structural reasons such as the uneven bottom surface of the slot 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 Carbide Grooving Inserts 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; ④ Use * cutting to reduce the impact on the blade.
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, causing excessive cutting vibration.
Countermeasures: ①Increase the auxiliary support of the workpiece to improve the rigidity of the workpiece clamping; ②Reduce the overhang length of the tool; ③Appropriately reduce the clearance angle of the tool; ④Use other anti-vibration measures.
11) Careless operation, such as: when the tool cuts in from the middle of the workpiece, the action is too violent; the tool has not been retracted, and it stops immediately.
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