Diamond Film n&k Coating (CVD Process)
Diamond film coatings are done to improve the surface hardness of cutting tools. Generally diamond film coatings can be classified into two. The thin diamond film coating with a layer thickness of approximately 5-20 microns and thick diamond film coating with a layer thickness of approximately 0.5mm. Higher thermal and chemical stability and ultra surface hardness are the advantages of diamond film n&k coating. Low fracture toughness is the disadvantage of of diamond film coatings. And compared to polycrystalline diamonds no binder is used while producing diamond film coatings which causes higher splintery fracture.
Diamond film coated ultra hard materials are best suitable for machining of aluminium alloys with high silicium contents as well as graphite and carbon. Tests show very good use of diamond coated tools in machining plastics, gold alloys and wood machining.
Polycrystalline Cubic Born Nitrite (CBN)
Polycrystalline Cubic Born Nitrite is the hardest cutting material after ultra hard materials like ceramics and diamond. CNB is manufactured by a sinter process of high temperature and pressure using selected particles of Cubic Born Nitrite. Depending on various cutting applications polycrystalline cubic born nitrite are available with with different binder phases as well as in fine, medium and rough grain structure. CNB is an ultra hard material with excellent thermal stability up to 1200°. Polycrystalline Cubic Born Nitrite with low cbn contents is mainly used in precision machining of hardened steel and other hard ferrous materials.
tag : n&k
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