Tungaloy Wear Problems And Solutions Chart For Carbide Inserts

BUILT UP EDGE

Excessive heat. Hard micro inclusions in the workpiece cut into the insert. Small pieces of the coating break off and also cut into the insert. The cobalt then wears out and the carbide grains no longer have any adhesion and therefore break off.

To avoid built up edge on your inserts, the following is recommended:

Select a more wear resistant grade.
Change the chipbreaker geometry.
Reduce cutting speed.
Use coolant.

CHIPPING

Chipping is caused when the insert grade is too hard for application conditions.

To avoid chipping your inserts, the following is recommended:

Use a tougher grade with higher cobalt content.
Reduce the risk of vibrations.
Select a larger nose radius.
Increase cutting speed.

CRATERING

Insert cratering is caused by excessive heat. In addition, cratering can occur when hard micro inclusions in the workpiece cut into the insert. Also, small pieces of the coating can break off and cut into the insert. The cobalt then wears out and the carbide grains no longer have any adhesion, and therefore break off.

EDGE DEFORMATION

Heavy feeds and high cutting speeds can cause edge deformation. The heat softens the insert structure, causing the cobalt to soften and the insert becomes deformed.

To avoid deforming the edges of your inserts, the following is recommended:

Use a more wear resistant grade.
Reduce cutting speeds.
Reduce feed.
Select an insert with a larger nose radius.

FLANK WEAR

Flank wear occurs when the insert grade is too soft and machine speed is too fast.

To avoid flank on your inserts, the following is recommended:

Reduce cutting speed.
Select a more wear resistant grade.
Use coolant.

NOTCHING

Notching occurs on an insert at the depth of cut line. This is usually due to work hardened surface, scale or abrasion.

To avoid notching on your inserts, the following is recommended:

Use harder, more wear resistant grade.
Reduce your cutting speed.
Reduce feed rate.
Use larger corner radius for shallow cuts.

THERMAL CRACKING

Rapid change in thermal loads can cause thermal cracking. Temperature difference between warm and cold zones causes thermal stress which leads to cracking of the insert.

To avoid thermal cracking on your inserts, the following is recommended:

Use heat resistant grades.
Use an abundant supply of coolant OR do not use coolant.
Reduce cutting speed.
Use positive rake tools.