2013年10月10日星期四

Diamond tool materials species classification

Synthetic polycrystalline diamond (PCD) and synthetic polycrystalline diamond and carbide composite blade (PCD / CC)
PCD is at high temperature ( about 1800 ℃), pressure (5 ~ 6MPa) , the use of cobalt and other metal binding agent to a  oncrete crack chaser number of polycrystalline diamond crystal powder polycrystalline material , although slightly lower than the hardness of a single crystal diamond , but it is randomly oriented diamond grains polymerization , is isotropic , as can be arbitrarily oriented cutting tool sharpening , no natural diamond that must be selected as the best cleavage plane as a rake . In cutting, the cutting edge is very sensitive for accidental damage , wear resistance is also strong , long stay sharp cutting edge , can be used when machining high cutting speed and larger cutting depth ( to eat deep ) , life concrete core bits  is generally higher than the WC-based cemented carbide cutting tools 10 to 500 times , and because the metal binding agent PCD has conductivity , making PCD easy to cut to shape , and is a rich source of raw materials , the price is only a few tenth of natural diamond a fraction of the ten have become traditions WC-based cemented carbide cutting tools , high-performance alternatives.
PCD inserts to improve the toughness and weldability in the cemented carbide substrate , sintered or pressed on the surface of 0.5 ~ 1mm thick layer of the composition of PCD diamond composite blade (PCD / CC). PCD / CC welding or machine folder available way of making knives. Due to its good weldability , regrinding easy , low cost, and polishing pads for granite  therefore widely used. Hereupon , PCD and PCD / CC sharp cutting edge of the tool and are not as good surface quality single crystal diamond , while its workability is poor, the grinding ratio is small , it is difficult according to the geometry of any shape head , still not easy to manufacture with chipbreakers indexable end mills and other geometric shapes and complex products.
CVD diamond
CVD diamond is a diamond material of high wear resistance of pure , non- binding agent , which is at low pressure (<0.1MPa) prepared under . CVD diamond films are coated CVD (CD) and CVD thick (TFD) forms.
CD is a CVD ( chemical vapor deposition ) process , the carbide substrate ( K type alloy used ) is deposited to a thickness of about 10 ~ 30μm, composed of a polycrystalline diamond film is made .

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