There isessential difference existing between the geometry angles of diamond and common coatings of cutting tools .Thus ,when design the diamond cutting tools coating ,since the particularity of the cutting tools for graphite ,we could enlarge the geometry angles and chip-holding groove appropriately without reducing the wear-resistance performance of the cutting edge of the tools.On the contrary ,for the common TiAlN coating ,also its wear-resistance is increased a lot comparing with the cutting tools without coating ,however ,its geometry angle should be reduce appropriately when machine graphite comparing to the diamond coating ,so as to improve its wear-resistance performance.
For the diamond coating of cutting tools ,now a many coating companies invest a lot of manpower and capital to research and develop related technology ,however ,only the European enterprises have been mature and economic in coating technology so far .
Strengthening on the cutting edges of tools
The passivation of cutting edge has not been paid widespread attention ,but it is really a very important issue,.The varying extent of micro-notches(micro-tipping and saw tooth) exist on the tungsten carbide cutting edge after ground with diamond grinding wheel .There is higher requirements for the tungsten carbide cutting tools with high speed machining for graphite ,especially for the diamond coating tools ,we have to take passivation on them before coating ,so as to keep its solidarity and service life.The passivation with aim to solve the micro-notches on the cutting edge after ground ,reduce the sharpness ,achieve smooth and flat ,so as to reach solidarity and wear-resistance .
