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Problems
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Causes
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Remedies
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Excessive Flank and Notch Wear
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a)Cutting speed is too high or insufficient wear resistance
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Reduce cutting speed or select a more wear resistance grade
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b)Oxidation
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Select a Al2O3 coated grade
For work hardening materials,select small entering angle or more wear-resistance grade
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c)Attrition
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Reduce the cutting speed
(when machining heat resistance material with ceramics increase cutting speed)
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d)Oxidation
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Select a cermet grade
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Crater Wear
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Diffusion wear due to too high cutting temperatures on the rake face
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Select a Al2O3 coating grade.
Select a positive insert geometry.
First reduce speed to obtain low temperature,then reduce the feed.
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Plastic Deformation
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Cutting temperature too high combined with a high pressure
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Select a harder grade with better resistance to plasticdeformation.
Edge depression
--Reduce speed
Flank impression
--Reduce feed
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Built-up Edge
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Workpiece material is welded to the insert due to:
Low cutting speed
Negative cutting geometry
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Increase cutting speed
Select a positive cutting geometry.
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Chip Hammering
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The chips are deflected against the cutting edge.
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Change the feed
Select an alternative insert geometry.
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Frittering
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Grade too brittle
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Select tough grade
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Insert geometry too weak
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Select an insert with stronger geometry(Bigger chamfer for ceramic inserts)
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Build-up edge
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Increase cutting speed or select a positive geometry.
Reduce feed at the beginning of cut.
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Thermal Cracks
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Thermal crack due to thermal variations caused by intermittent machining.
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Select a tough grade with better resistance to thermal shocks.
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Varying coolant supply
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Coolant should be applied copiously or not at all.
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Insert Breakage
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Grade too brittle
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Select a tougher grade
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Excessive load on the insert
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Reduce the feed or depth of cut
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Insert geometry too weak
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Select stronger geometry
Preferably a single sided insert
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Insert size too small
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Select a thicker or larger insert
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Slice-fracture Ceramics
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Excessive tool pressure
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Reduce the feed
Select a tougher grade
Select an insert with smaller chamfer.
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