An added benefit of IAC is the ease in which PCD and carbidemicro-tools can be manufactured. Since IAC maintains the optimaldistance, the chance of wheel collisions and the resulting tool breakage is very low, which is critical when eroding tools under 0.5 mm.
Optimize the Erosion Process With
Adaptive Spark Control
The current, voltage, duration, time-off, and intensity of sparkschanges based on the material being eroded. For example, PCD willrequire certain parameters as opposed to carbide (HM) and high-speed steel (HSS). The challenge is that PCD wafers are generally 0.6 mm with a 1 mm carbide backing—sintered PCD, chevrontools, and solid-tipped tools are formed onto carbide backing also.
When aggressively eroding along the PCD-carbide border, erosionparameters optimized for PCD can inadvertently over-erode thecarbide backing. This leads to over-erosion at the PCD-carbide border, named an “undercut” as it selectively erodes the carbide under the PCD. Additionally, it can lead to “cobalt leeching” which iswhen the PCD binder, cobalt, is preferentially eroded away.
This is akin to digging under the foundations of a paved pathway.If you dig too much material away from under the path, eventuallythe path will collapse. Machine testing showed that the undercut andcobalt leaching during heavy leaching roughing lead to a brittle border along the cutting edge and premature tooling wear. To avoid thisand to optimize the erosion process, Adaptive Spark Control (ASC)was created.
the chance of wheel
the resulting tool
breakage is very
low, which is critical
when eroding tools
under 0.5 mm.
Simple and very complex PCD tooling. Note the solid tipped PCD drill. Credit: ANCA