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freerangestock.com i.e., the curve showing the running-in, steady-state, and
acceleration phases. Using these blades did not modify the
nature of the wear curve; for example, it did not eliminate
the running-in phase.

In the case of blades with WC grain sizes of 0.4 µm and
0.1 µm, analysis of the curves indicates two-period wear
behaviour during which the intensity of wear changes.
Optical microscope images of a worn edge have been
illustrated that had been produced following the milling of
a chipboard with blades manufactured from carbide with
submicron WC grain sizes of 0.4 and 0.8 µm, respectively.
intervals of 1 m along the feed distance, which corresponded These images reveal that wear of the cutting edge occurred
to the length of the particleboard. The condition of the blade on the work surface as a result of friction between the work

was meticulously monitored utilising a shop microscope until surface and the workpiece. Concurrently, they render the
the dullness criterion of VBmax = 0.2 mm was attained. The uniform progressive wear of the tool edge perceptible.
milling process is schematically. Conversely, tools exhibiting a nanometric WC grain size
of 0.1 µm demonstrate a high prevalence of breakouts and
Table 3. Cutting parameters.
chipping along the edge, ultimately leading to severe tool
Spindle Rotation Feed Rate per Tooth, Fz Feed Rate, u
(rpm) (mm) (m/min) degradation.
At the nanoscale, the material’s structure becomes more
15,000 0.25 3.75
complex, with greater effects associated with grain boundaries
appearing. This can cause an uneven distribution of internal
Following the conclusion of the milling process, the carbide stresses.
blades were extracted from the tool holder, and the cutting The fine-grained structure of nanometric carbides can
edge was subjected to scrutiny using a JEOL 6610LV scanning lead to localised stresses at grain boundaries, potentially
microscope equipped with a LaB6 cathode and a Keyence causing cracking.
VHX-6000 digital optical microscope at a perpendicular angle Additionally, materials with nanometre-sized grains may
to the cutting surface. exhibit defects such as dislocations and cracks. The presence
The cutting edge was traced along its entire length, and of these defects, combined with the conditions during the

photographs of the wear profile were taken. The extent of milling process, can exacerbate mechanical stresses.
wear on each blade was determined by measuring the area The wear rate of each variant of the tested blades, as
under the wear profile. determined by the area under the wear profile, was found to
be similar across all variants.
Results It is possible to discern variations in the configuration of
The tools were withdrawn from further testing once they such a profile. It has been demonstrated that the finer the
reached the established wear criterion of 0.2 mm. grain, the more numerous the chipping and breakage of the

The curves obtained for the WC-Co 0.8 µm tools were cutting edge.
similar to the classic wear progression curve (Lorentz curve), SEM images of the worn edges of 0.8 and 0.4 µm blades