Sandvik Coromant Heat resistant super alloys - Manual (Page 14)

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Top slice wear – this type of wear is com-
mon for ceramics in HRSA. Small slices of
the cutting tool material are lost around
the insert’s top face. When the flank of
the insert is worn, the workpiece pressure
against the periphery will be high enough
to break small slices away along the edge
line.
The recently sliced area will then form a
new sharp edge that again cuts well, and
the cutting process can continue under
these circumstances for a long time without
posing a threat to the overall quality, in less
sensitive roughing or semi-finishing opera-
tions.
In finishing operations, where surface qual-
ity and/or burr formation is important,
top slicing can be critical. This tendency
increases with high feed rates due to
increased radial pressure.
To reduce top slice
In stable conditions:
• Lower the cutting pressure by reducing
the chip area:
– feed rate
– depth of cut, ap
– arc of engagement
• Use optimized programming techniques
• Use CC670 which is stronger due to
whisker reinforcement.
In unstable conditions where top slice is
caused by vibrations:
• Reduce engagement angle with program-
ming techniques
• Use CC6065 rather than CC6060
Small slices are lost around the
insert’s top face