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Here, we introduce the knowledge and various knowledge
about the product TAKAMAZ a variety of machine tools.
I hope you will help the daily work of customers.

The 5th METHOD OF EXTENDING TOOL LONGEVITY IN
ELECTROMAGNETIC SOFT IRON CUTTING
Experiment 2: Comparisonby Changing the Cutting Speed
Electromagnetic soft iron isused in parts that require
magnetic response, and the market
demand for cutting this material
is increasing.
When cutting electromagnetic
soft iron, the tools are subject
to steady and continuous wearsuch as from "abrasive wear","diffusion wear" and "deposit spalling". However,
due to the lack of studies and analyses of thistool wear, tool manufacturers still have yet tofind a good solution in cutting electromagnetic
soft iron. Focusing on finishing tools, we haveobtained the optimum tool life extension methodwith the support of tool manufacturers.Here wewill introduce the method as well as the process
we took to reach it.

These photos show tool nose wear conditions after
4 km of cutting at different speeds. The face inphoto 2 shows deposit generation but under
the high-speed cutting in photo 4, deposits decrease.
This implies that in high-speed cutting, the cutting
temperature exceeds the temperature range where
deposit generation easily occurs. From this we cansee that cutting at high-speeds may be free froman inhibitor of tool life extension. In low-speed
cutting as in photo 2, the wear is smooth and glossy,
while in high-speed cutting it is coarse and burnt.
It is assumed that this is because abrasive wear isdominant in low-speed cutting, and thermallyaffected wear is generated in high-speed cutting.
Photo 2

Photo 3

Photo 475m/min

350m/min450m/minExperiment 1: Determination of the Test Tool
Cutting conditions:：V=150m/min、f=0.05mm/rev、D=0.4mm More than 40 kinds of inserts were tested
and almost all of them showed a wear shape asshown in the photos below.

Amount of wear on minor flank (vs. cutting distance)

Width of wear(mm)Photo 1

cutting distance(km)In the test cutting conducted for short distance
500 m, the flank was worn smoothly as if it were
polished, and the coated layer on the face flaked
along the chip flow. This wear, considered tobe diffusion wear and abrasive wear, propagatescontinuously until the end of the tool life.
In Experiment 1, a number of tool manufacturer's
inserts showed favorable results. Among them,
we selected "KP006" (Sumitomo Electric Industries)
for further testing with various cutting speeds
and cutting fluids.

This graph shows how the width of the wear area on
the flank changes according to cutting speed and cutting
distance. At a cutting speed lower than 250 m/min,large initial wear is observed and propagation of wear
is slowed as the cutting distance increases.
At a cutting speed higher than 350 m/min, initial wear
shows a slow increase, but at 450 m/min, rapid propagationof wear occurs after 2 km of cutting. Analysis of thisgraph indicates that the wear factor differs at under
300 m/min and over 300 m/min, and that tool wear isminimal at around 300 m/min.

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Experiment 3: Comparisonby Changing Cutting Fluid
In Experiment 3, tool wear is comparedby changing cutting fluid - dry cutting,semi-dry cutting with fluorinated fluid,
water-soluble coolant and oil-based coolant.
The experiment proved, as shown in thegraph above, oil-based coolant gives the best
result.In addition to this, although
the width of the wear area on the flankdoes not change much, the localized wearon the face propagates remarkably with
cutting fluids other than oil-based coolant
and deforms the tool nose shape, reaching
the end of the tool life before the widthof the wear area reached 0.2 mm.

Finally, we would like to briefly introduce
the features of "KP006" which we used in the test.
Among various features, the most notable isthe super nano-micron thin film coat, which iscalled "SUPER ZX COAT". This super-thin film
coating technology enables multi-layer coatings
having different properties such as oxidation
resistance, abrasion resistance and lubricity,
thereby realizing a coating film with compoundfeatures. Whereas conventional coating can provide
only a single feature, multi-layer coatings withcontradictory properties can be created withthis super-thin film coating technology. Therefore,
inserts with multi-layer coating can be used ina wide range of cutting speeds from low to highand cope with complex wear factors.

Extra Information
Width of wear(mm)Slashing turret change time on a compound lathethat features Y-axis such as Takamaz XY-120 andXY-1000.

cutting distance(km)To Improve Tool Life in Electromagnetic
Soft Iron Cutting
From the results of tests, we found the factors
to take into consideration to extend tool life
as follows. 1. Use oil-based coolant 2.
To shorten cutting time per workpiece, selecta high feed rate and a cutting speed as highas possible but under 350 m/min. 3. Set 0.2 mmor larger for depth of cut. 4. Selectthe appropriate insert type by testing several
types since some types cannot be used forelectromagnetic soft iron cutting. 5. Selectan insert having a sharp edge and smooth chipbreaker to reduce depositing.

The photo shows a combination holder where a totalof four OD turning tools (two tools in the main
spindle direction and two tools in the sub-spindle
direction) are mounted on a single turret.
With the tool tips arranged within the Y-axis stroke,
tool change is possible by offsetting the Y-axis
without requiring turret change. This feature canshorten cycle time and increase the number ofmountable tools. Use of the KM tool (Kennametal Inc.)
provides remarkable improvements in tool change
efficiency. Note: Restrictions may apply due topart dimensions or interference. Will be released
after June this year.