5 Difference Between PVD and CVD Coating
PVD and CVD are the currently popular coating process on the cutting tools and moulds,the difference as following for your reference:
1)The CVD based on chemical vapor deposition,but the PVD is physical vapor deposition.
2)The PVD coating film is 3~5um,which is much thinner than the CVD one's as 10~20um.
3)The coating processing temperature for CVD is 800~1000℃,but for PVD is only around 500℃.
4)CVD coating is mainly used in tungsten carbide products,as it requires the workpiece with capability to bear the high temperature in coating
process,meanwhile,as the processing temperature is very high and coating thickness is very thick,easily leading to tensile stress on the work
piece surface and micro-cracks emerged ,especially the cracks under the external force such as milling would be expanded,resulted in coating
films dropped off and its protection function unworkable,so the CVD coating is mostly taken on the carbide turning inserts,as in the whole
turning process,the force is evenly and continuely,especially the thick CVD coating with good wear-resistance performance showed up obviously.
5)PVD coating with low processing temperature as only 500℃,so in the coating processing,mainly creates pressing stress,not tensile one,which
prevent cracks from emerging and expanding,adding the PVD film is very thin,so would not change much of the cutting edge's geometry profile and
keep its sharpness at the most extent,which is very helpful to reduce the cutting force and heat,thus the PVD coating is more suitable for the
tungsten carbide inserts with intermittent milling process and all the solid cutting tools
