CS252707B1 - Method of titanium nitride's abrasion-proof layer formation on solid conductive substrate - Google Patents

Abstract

The essence of the method of making abrasion resistant titanium nitride layers on solid electrically conductive substrate, which is a cathode in the ionic coating system on the negative electrical potential versus grounded vacuum the chamber is that on the substrate giant at a temperature above 200 ° C is working an inert gas plasma; vapor-subliming tungsten hexacarbonyl under reduced pressure from 10 ~ 3 Pa to 10 Pa, behind the substrate with nitrogen-containing plasma vapor-evaporated titanium, under pressure from 10 ~ 3 Pa to 10 Pa.

Description

The invention relates to a method of forming a wear resistant layer of titanium nitride on a solid electrically conductive substrate under vacuum in a plasma.

At present, there are a number of methods and processes by which layers of titanium nitride can be formed on solid substrates. The most important methods are the chemical coating method, so-called. CVD method, furthermore are magnetron sputtering and ion cladding methods.

A considerable disadvantage of chemical deposition of titanium nitride layers is the necessity of heating the substrate to a temperature of 900 ° C to 1100 ° C, the layers thus formed are in many cases poorly adherent and in many cases their surface has poor microgeometry. Reactive ion sputtering and ion cladding methods are currently capable of forming titanium nitride layers on high speed steel, aluminum alloys, titanium alloys, structural and tool steels, etc. at temperatures up to 550 ° C, however, due to the inhomogeneities of the surface properties of these substrates, in many cases the unsatisfactory adhesion of titanium nitride coatings occurs, which has a negative effect on wear resistance. and other utility properties of the washer-layer system.

In the prior art methods of preparing titanium nitride layers, the advantageous properties given by the combination of a tungsten thin layer and a titanium nitride layer as a coating on an electrically conductive substrate have not been used.

The above drawbacks overcome the method of forming an abrasion-resistant titanium nitride layer on an electrically conductive substrate according to the invention which is based on a solid electrically conductive substrate which is a cathode in an ion-plating system at negative electrical potential over a grounded vacuum chamber and heated to a higher temperature. above 200 ° C and below the melting point of the substrate is treated with an inert gas plasma, usually argon, and tungsten hexacarbonyl sublimating vapors at reduced pressure from 10 ^-3 Pa to 10 Pa, immediately resulting in a solid electrically conductive substrate it works with nitrogen-containing plasma and vaporized titanium vapor under reduced pressure from 10 ^-3 Pa to 10 Pa.

The invention is illustrated by the following examples.

A steel substrate was placed in a vacuum chamber pumped to the initial pressure of ³ Pa lO, as the electrode forming a cathode over the grounded vacuum chamber. After the substrate was cleaned and heated to 200 ° C in a glowing argon discharge at a pressure of 2.10 &^lt; ^-1 > Pa and a negative electrical potential of -3.2 kV on the substrate against a grounded vacuum chamber, sublimation of tungsten hexacarbonyl was initiated by resistance heating. Under these conditions, tungsten hexacarbonyl vapors in the plasma space and on the surface of the substrate decomposed into tungsten at birth and carbon monoxide to form a 0.4 μΐη tungsten layer on the surface of the substrate. After the formation of this layer, the tungsten hexacarbonyl vapor and argon vapors were closed and immediately thereafter titanium was evaporated by electron beam method at 3 kW beam at a nitrogen pressure of 3.10 ^_1 Pa and with a negative electrical potential having a substrate of –3.2 kV compared to a grounded vacuum chamber. In this way, a layer consisting of tungsten and titanium nitride of 0.4 μΐη and 5 µm thickness was formed on the steel support.

In another case, a substrate of SK was used, on which a tungsten and titanium nitride layer of 0.2 µm and 4 µm depths was prepared as described above, at a substrate temperature of 600 ° C, a potential of 3 kV, a pressure of 10 " ^2. Pa in the preparation of a tungsten layer and a pressure of 5.10 ^l Pa in the preparation of a titanium nitride layer. UWJ

The coatings prepared at the parameters described above exhibited increased adhesion over coatings that were free of tungsten interlayer and differed in different structures depending on the preparation parameters.

The layers prepared according to the invention show: increased adhesion to the tungsten layer thicknesses of less than 1 μΐη over titanium nitride layers prepared without the tungsten interlayer. At the same time, high wear resistance and good frictional properties due to titanium nitride properties are maintained with these tungsten backing layers. These properties predetermine the layers to be applied to instruments, in particular gray ones, and to particularly stressed tribological nodes.

Claims (1)

SUBJECT A method of forming a wear-resistant titanium nitride layer on a solid electrically conductive substrate, which is a cathode in an ion-plating system at a negative electrical potential compared to a grounded vacuum chamber, characterized in that an electrically conductive substrate heated to above 200 and tungsten hexacarbonyl vapor sublimation under vacuum in the range 10 ^"3 Pa to 10 Pa, to thereby directly to a solid substrate electrically conductive It acts plasma consisting of nitrogen and vapor of the evaporated titanium under vacuum in the range 10 ^-3 Pa to 10 Pa.