Graphite is used to make edm electrodes. Which are the better techniques to machining graphite? Is the machine-tool a special machine?.
You don't need special tools or machine to cut graphite into any designed shape, as graphite is a very soft material. BUT what you absolutely need to pay attention to, is protecting the motors and all electric device from graphite dust. Graphite dust is indeed highly conducting, so it is extremely easy to produce short circuits, and therefore irreversibly damage the motors if you allow graphite powder to deposit everywhere. Sucking up graphite dust with a vacuum cleaner should be avoided as well, as dust is able to pass through the filters and make short-circuit in the cleaner motor. So there is nothing else to do but covering thoroughly all electric devices and motors when machining graphite.
Alain
It's not whole true, that You don't need to use special tools to remove graphite. This is material which very fast can demage tools (wipes) if You do not use DIAMANT coating. If You use a DIAMANT COATING (more expensive that normal of course) tool, this will percentage in the future. Second problem is to use monolite or removing plate tool. To rough machining, You can use plates, but for finally machining You should use monolite tools. And third problem is strategy. I have noted, that the best way to save Your tool is use a strategy with as much smoth moves as possible. And very importent is to stay in one place as least as possible, because in other case, Your tool will be wipeing.... By the way graphit is very plesant material to removing, so You can go with quite large ap. Resisting of engines,cables and rotors also is very important. Filters!!!!
Tadeusz
Kindly go through the following link
In SEMO CARBON blog the tips mentioned are Quote in "
Graphite machining can be challenging. Especially if you are not prepared to work with it's unique and messy properties. As a custom graphite machining facility as well as a supplier of graphite material blanks, we have answered may customer questions over the years about the difficulty of machining graphite correctly. The following is a list of five key concepts to keep in mind when attempting to successfully machine synthetic graphite.
First, synthetic graphite should be machined dry without the use of liquid coolants. The use of coolants when working with graphite will produce an abrasive slurry when the coolant combines with the fine bits of graphite chips and dust. The coolant fluid will also permeate the graphite material through the open porosity of the material. Essentially the graphite will act as a sponge, as capillary action draws the coolant into the open pores. This contamination will cause problems when the graphite is used in an application that requires the inert nature of the graphite material.
Second, the starting raw graphite material should be dry before machining. If your raw material stock has been stored outside or been exposed to water it should be baked to drive out any excessive moisture. The water and dust will make an abrasive slurry, which will dramatically reduce your tool life. This issue can be most clearly observed when cutting wet graphite on a band-saw. The dust does not exit the material during cut and packs up in the kerf. Essentially the cutting tool re-cuts the same graphite chips over and over again.
Thirdly, it is very important to have an adequate ventilation system to contain and vent the graphite dust and chips produced during the machining operations. Graphite dust is electrically conductive and will find its way into every crack or opening in a machine enclosure. Static electricity will draw the dust to circuit boards and create short circuits when the build up bridges contacts. Machining graphite on a CNC machine that has not been specifically modified to handle the graphite dust can lead to expensive damage and potentially void a warranty.
Fourth, graphite machining should be done with very sharp tooling to prevent particle pull-out or edge chipping. Once a cutting tool has lost its sharp edge it will fracture the graphite material or cause a blowout of an edge when exiting a cut. This is because the dull tool is pushing and not cutting the material. Graphite has great compressive strength, but will fracture if the force is directed out of the material rather than into it. Tooling made from micro-grain carbide designed for cast iron works well in graphite. Vapor deposition diamond coated endmills also work well, but can be very expensive.
Fifth, it is a good practice when milling graphite to ''Climb Mill'' or work from the outside into the material. When milling pockets avoid leaving islands when the endmill cuts from the pocket perimeter into the center of a pocket. The island material will break out when the final island is removed resulting in a pockmarked cavity. It is a better practice to drill a center hole and mill the pocket from inside to the outer edge. " Quote out the above mentioned tips can be accessed by following below link hope it is useful
http://www.semcocarbon.com/semco-carbon-blog/five-keys-to-success-when-machining-graphite
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