Page 52 - MTW November 2022 Digital Magazine_R1

TECH INNOVATION

Face Milling for High Surface Finish

In the metalworking industry, ensuring a high-grade surface finish has always been one of the main directions in
cutting tool development. This is also true for indexable face milling cutters.

espite significant improvement in the high surface quality
of milled surfaces, tool designers still believe that available
Dresources have not yet exhausted and that intelligent
applications of the last generations of advanced milling cutters
can substantially improve surface texture.
When considering an indexable milling cutter, the key factors
that determine the quality of a generated surface are the
cutter’sgeometry and accuracy. Both characteristics are mainly
related to inserts carried by the cutter.
Powder metallurgy processing has enabled producing carbide
inserts with complex shapes, ensuring optimal cutting geometry
while maintaining substantially increased accuracy of inserts
as sintered inserts. Not surprisingly, such advancements in
technology have significantly improved the surface finish in
face milling. However, when indexable milling cutters were
successfully applied to machining high-strength materials, and
manufacturers started to notice hard milling as an alternative to
grinding, the metalworking industry started demanding higher
surface finish grades provided by milling. Fig. 1–NEODO double-sided square rough milling inserts
withan integrated wiper flat to provide better surface finish.
Indexable face milling cutter
An indexable face milling cutter is a multi-tooth tool. More teeth accuracy loss is the insert pocket in a cutter has its own
means more productivity. This is an undeniable advantage of the dimensional and form tolerances. As a result, even for ideally
cutter. But, in terms of surface texture, a large number of teeth precise inserts, teeth protrusion will vary within acceptable
may be a problem. A fine distinction in teeth protrusion leads to limits, although it cannot ensure extra fine surface finish when
irregular feed for the teeth and contributes to chatter, which will compared to grinding. A way to overcome this problem is by
ultimately affect the surface finish. using a fly cutter that carries only one insert. The fly cutter that
It is perfectly clear that insert accuracy can considerably be is successfully used in various milling applications facilitates a
increased by grinding. Moreover, grinding smooth and clean cut, providing excellent
provides a sharp cutting edge that is very surface texture parameters. But then again,
important in maintaining cutting action and A tendency to productivity in this case is far below multi-
preventing plastic deformation of metal in decrease machining allowance tooth indexable face mills.
fine milling, which features shallow depths due to the active introduction
of cut. Ensuring a highly accurate cutting of technologies for precise Balancing quality and productivity
edge requires grinding both the top and workpiece production and 3D How to solve a difficult situation and find
side surfaces of an insert. This may cancel printing makes the issue of an acceptable balance between surface
the advantages of powder metallurgy in obtaining a high surface finish quality and productivity? The cutting tool
generating complicated surfaces to provide by face milling particularly manufacturer has developed different ways
required rake and clearance angles along relevant. Can toolmakers find to answer.
acutting edge. To avoid such an adverse a prompt, simple, and effective An integrated wiper flat with a specially
impact, tool engineers should be very shaped minor cutting edge is a classical
resourceful when designing the inserts answer to the new needs element of various milling inserts. Its width
intended for fine grinding. of manufacturing? The near should be greater than the feed per revolution.
An important factor regarding tooth future will tell. Despite being called flat, the minor edge

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