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3601 E. 34th St. Tucson, AZ 85713 USA Tel. +1 520-882-6598 Fax +1 520-882-6599 email: pace@metallographic.com
Figure 9-4a Fine diamond cut for boron graphite
composite
The second most important blade characteristic is the abrasive concentration because it directly effects
the load which is applied during cutting. For example, brittle materials such as ceramics require higher
effective loads to efficiently section; whereas, ductile materials such as metals require a higher abrasive
concentration in order to have more cutting points. The result is that low concentration blades are
recommended for sectioning hard brittle materials such as ceramics and high concentration blades are
recommended for ductile materials containing a large fraction of metal or plastic.
TIP: Minimizing the amount of damage created du ring sectioning can significantly
reduce
the amount of time required for grinding and polishing
The wafering blade bonding matrix can also significantly effect a blades cutting performance. Metal
pressed wafering blades require periodic dressing in order to maintain performance. A common
misconception is that the cutting rates for these blades decrease because the diamond or abrasive is
being "pulled-out" of the blade. In reality, the metal bond is primarily smearing over the abrasive and
"blinding" the cutting edge of the abrasive. With periodic dressing using a ceramic abrasive encased in
a relatively soft matrix (Figure 9-5), this smeared material is removed and the cutting rate restored.
Figure 9-6 shows the effect of dressing a standard grit, low concentration diamond blade for cutting a
very hard material such as silicon nitride. Without dressing the blade the cut rate significantly
decreases after each subsequent cut. After dressing the blade, the sample once again cuts like a new
blade. Note it is highly recommended that a dressing fixture be used for conditioning or dressing the
wafering blades in order to reduce the risk of breaking or chipping the wafering blades (Figure 9-7).
Blade dressing is also accomplished at low speeds (<300 rpm) and at light loads (<100 grams).
Please read this instruction manual carefully and follow all installation, operating and safety guidelines.
PICO-155S Precision Saw
Figure 9-4b Medium grit diamond cut for boron graphite
composite
I
M
NSTRUCTION
ANUAL
Web: http://www.metallographic.com
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