Droplet-free coating systems manufactured by arc-evaporation method
A droplet-free wear-resistant coating is manufactured by depositing a wear resistant nitride coating containing a nitride layer which contains at least one metal or metal compound of a metal selected from the group consisting of Ti, Cr, Al, Si and combinations thereof, on a surface of a substrate by cathodic-arc evaporation using a Venetian blind filter system in front of an arc cathode; to reduce metal microdroplets and/or metal microparticles in the wear resistant coating compared to an wear resistant coating obtained without a Venetian blind filter system.
1. A method for manufacturing a droplet-free wear-resistant coating, comprising:
depositing a wear resistant nitride coating comprising
a nitride layer comprising at least one metal or metal compound of a metal selected from the group consisting of Ti, Cr, Al, Si and a combination thereof,
on a surface of a substrate by cathodic-arc evaporation using a Venetian blind filter system in front of an arc cathode; thereby reducing metal microdroplets and/or metal microparticles in said wear resistant coating compared to an wear resistant coating obtained without a Venetian blind filter system,
wherein the filter system comprises Venetian blinds having a spacing of from 5 to 40 mm from one another,
wherein a density of the metal microdroplets and/or metal microparticles with a geometric dimension of >1.5 μm in cross section is reduced by at least 75% in said coating, and
wherein a deposition rate is 1.5 to 3.0 μm per hour.
2. The method according to claim 1 , wherein a pressure of the deposition is from 2 to 7 Pa;
wherein said filter has an anode potential or a floating potential; and
wherein an external magnetic field is generated with a magnetic field coil having 6 to 10 turns and 30 to 60 A per cable.
3. The method according to claim 1 , wherein said substrate is a rotating chip-removing tool.
4. The method according to claim 1 , wherein said substrate is a drill, end-mill, screw tap or reamer.
5. The method according to claim 1 , wherein said Venetian blind filter system comprises the filter-plates which are arranged in a linear Venetian blind structure and oriented parallel to one another in a direction of a plasma flow in open configuration of said Venetian blind filter system.
6. The method according to claim 1 , wherein an electric current is passed through filter plates of said filter system, thereby generating a magnetic field.
7. The method according to claim 1 , wherein an electric current is passed in opposite direction through adjacent filter plates of said filter system, whereby magnetic lines of force are aligned and pass through spaces between said adjacent filter plates in substrate direction.
8. The method according to claim 1 , wherein a density of the metal microdroplets and/or metal microparticles with a geometric dimension of >0.8 in cross section is reduced by at least 75% in said coating.
9. The method according to claim 1 , wherein said substrate is a cutting tool or a wear part.