JPH045750B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF INDUSTRIAL APPLICATION The present invention relates to a method for applying a coating to cosmetic and utilitarian parts, said coating having a color similar to gold (10K to 24K) and/or from gray to brown. , bronze, black and platinum, where the coating has excellent adhesion and excellent resistance to corrosion and abrasion. Typical parts requiring abrasion resistant or decorative coatings include class rings, watch cases and bands, lighter cases, silverware parts, auto parts, eyeglass frames, pen caps, Tools and other worn (utility) parts. BACKGROUND OF THE INVENTION Thin film materials are applied to base materials for decorative applications in two ways. That is, deposition (metsuki) technology by sputtering,
and ion plating deposition techniques. However, typical substrate temperatures involved in both of these techniques are in the range of 350-550°C. These techniques are described, for example, in U.S. Pat. No. 4,402,994, U.S. Pat.
Technology”A, Vol.4, NO.6, Nov./Dec.,
1986, pp. 2717-2725. However, many substrate materials cannot be exposed to these high temperatures, such as plated zinc coatings, brass, bearing steel, bronze and its alloys containing zinc, plastics, aluminum and its alloys, etc. Additionally, due to the pale yellow or other pale colors commonly obtained by these techniques,
A mantle consisting of a thin gold film over a hard film surface is required. This is US Patent No.
Described in No. 4415421. The adhesion of the cooperating surfaces between the rigid film and the gold film and the color reproduction are important to the manufacturing technology. However, the above processes (techniques) are not always satisfactory in these respects. U.S. Patent No. 3625848 and U.S. Patent No. 3793179
No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, 2003, 2004, 2003, discloses an apparatus for metal vapor deposition coatings involving the use of a vacuum arc. An improvement in this regard is described in US Pat. No. 4,430,184. The above three patents are incorporated herein by reference. Such arc sources contain a high degree of ionization and produce a coating melt having high ion energy. This results in a coating with a dense microstructure and excellent adhesion. However, conventional arc sources require typical substrate temperatures in the range of 300-500°C. SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to develop an arc for depositing decorative and wear-resistant coatings that reduces to the very low base temperatures that are essential for many parts. The object of the present invention is to provide a source and method of technology that has not heretofore been commercially applied to such coatings. Another object of the present invention is to provide a method and apparatus for depositing materials onto a substrate at very low temperatures (temperature range of about 50-500 DEG C.) by vacuum cathodic arc plating. Another object of the invention is that without using gold,
The object of the invention is to provide a method for coating substrates with good adhesion and good decorative properties. Yet another object of the invention is to provide a method for applying non-golden decorative coatings using the apparatus described above. Another object of the invention is to enhance the color reproduction and abrasion resistance of decorative films at manufacturing scale. The method of the invention involves placing a base layer in a vacuum vessel and producing a melting solution of zirconium, consisting of ions, vapors and/or neutrals, on the base layer by the action of an electric arc within said vacuum environment. consists of evaporating. The composition of the deposit is:
They can be modified to produce different films by re-reacting with appropriate gases during their deposition. The temperature of the base layer can be controlled by automatic pulsing of the arc source. The "on" and "off" times of the arc source can be varied to control the temperature of the base layer down to temperatures as low as approximately 50°C. Furthermore, the adhesion of the coating can be improved by adjusting the bias voltage on the base layer to attract ions. The coating consists of a zirconium and titanium-zirconium based system. The color can be modified by adding suitable additives to the film, such as oxygen and carbon, where the additive gases typically range from 2 to 7 atomic percent; Alternatively, the color can be changed by using a suitable reactive gas atmosphere. Different ranges of gold (10k to 24k) are e.g. Ti _x N _1-x or when O<x<1
doubled in Ti _x Zr _1-x N and doped TiN or ZrN films. (Detailed Description of Preferred Embodiments of the Invention) Hereinafter, embodiments will be described with reference to the drawings. The present invention overcomes the shortcomings of the prior art by improving the fit and color reproduction in cathodic arc plating methods and apparatus. The present invention is applicable to coatings made of a variety of materials including zinc, aluminum, stainless steel, plastic, brass, and alloys thereof. Of the base layers coated with a hard material according to the invention, the surface of the tool or part is coated with a hard coating material of zirconium. Referring to FIG. 1, an arc plasma plating apparatus 100 according to an embodiment of the present invention is illustrated. An arc source 110 is operated within the vacuum vessel by an external pulsed power supply 105. A base layer 103 to be coated may be mounted on the rotary table 102. The rotary table 102 is connected to an external high voltage supply source 104.
may be given a negative bias. supply source 10
4 and 105 may be grounded, as shown in FIG. 1, or connected to a suitable source of negative potential. The device 100 is also equipped with a gas introduction pipe 106 and a vacuum pump system 101. A set of valves 1 for various gases
07 to the gas introduction pipe 106. A shutter 108 may also be employed. Additionally, the arc source may be partially commutated (not shown) to reduce coating flow to control substrate temperature. FIG. 2 shows a schematic diagram of an illustrative arc source 110 in which the material to be vaporized is heated using the action of an electrical arc. The arc source may be installed in the vacuum chamber in the form of a side, top or bottom. Arc restriction on the same arc source is achieved by the suppression ring 113
This is achieved using This restriction ring 113 is
It may be composed of boron nitride, titanium nitride, pyrex glass (heat resistant glass), quartz or soda coal glass. Arc restriction can also be achieved using suitable boundary shields or magnetic fields. In the latter technique, there is an extinction of the arc, which is e.g. disclosed in US Pat. No. 3,793,179.
It is automatically reignited using a suitable electronic control unit. The power source 105 may be DC if the target is conductive and the RF is insulating. The anode 114 is the cathode or the target 1
It is separated from 02. The anode 114 may be on the outer housing of the arc source, or on or around the wall of the chamber, and may be electrically biased or grounded. The anode 114 is spaced apart from the walls and base of the chamber 100 and at a separate bias to act as an anode for the electrical system, as shown in FIG. 2 and described in U.S. Pat. No. 3,625,848. It may be physically attached within the chamber 100 in a state where it is provided with. Additionally, the entire chamber or its surroundings may have a ground potential to act as a cathode for the electrical arc system (see, eg, US Pat. No. 3,793,179). FIG. 3 shows the operating cycle of the power supply 105. The time T ₁ at which the arc source is energized (on) and the time T ₂ at which the arc source is turned off can be independently varied;
For example, T ₁ can be hours when the arc source runs continuously, or it can be minutes when the arc source runs in pulses. Time T ₂ can be zero or a finite value. A typical valve for pulse peak is 30~
Varies within a range of 200Amp. Referring to Figures 3A and 3B, the third
Figure A is an illustrative block diagram of a control circuit for use with the arc source of the present invention, and Figure 3B is a program that may be employed within the control device of Figure 3A. FIG. 2 is an explanatory flow diagram of a subroutine of FIG. In FIG. 3A, the control circuit 120 is shown in its entirety and includes a programmable process controller 122. In FIG. The control device 122 is the
Model from a company called Instruments Corporation
Available as TCAM 5230, this control device is provided with a program for controlling the cathodic arc process. According to one feature of the invention, the program is modified by adding program steps to the program that may correspond to those illustrated by the flow diagram of FIG. 3B. The control device 122
includes an output section 128 that controls the magnitude of the current supplied by the arc source 105, and an output section 128 that controls the magnitude of the current supplied by the arc source 105;
04. The controller 122 is also traditionally adapted to receive a signal from a temperature sensor 132, and the controller 122 is adapted to receive a signal from a temperature sensor 132 to facilitate processing of the output signal from the temperature sensor 132. It includes internal analog-to-digital circuitry to digitize the output signal. The temperature sensor 132 is
Typically, it may be a conventional infrared sensor that reads the temperature of the base layer 103. This temperature will henceforth be referred to as T _S. The controller 122 also traditionally includes an output 134 for turning the arc source 105 on and off. Conventional output section 1
35 is also provided, which connects coil 115' to initiate arcing from target 102.
is connected to an ignition device 115, in which case the ignition device 115 may be of the electromechanical, electrical, or gas-emitting type. To explain the operation, a program traditionally supplied using the control device 102 is sent to the output section 12.
It is possible to set the magnitude of the arc current from 8 to 8. It also allows setting the magnitude of the bias voltage provided by the power supply 104. In modifying the program, in accordance with one feature of the invention, the subroutine of FIG. 3B is entered at 137 and the substrate temperature is read at 134. Next, the base layer temperature
T _S is compared with the lower limit temperature T _L at 136 . If, for example, it is desired to maintain the average temperature of the base layer 103 at about 100°C, the lower temperature limit T _L would be about 90°C. If the substrate temperature is lower than T _L , a current is output from output 136 via igniter 115 to start the arc, indicated at 138 . This instant corresponds to one of the leading edges of the pulses shown in FIG. As mentioned above, the magnitude of the pulse is traditionally controlled from the output 128. Once the pulse is initiated, the subroutine of FIG. 3A exits at 139, resulting in the return of the main program traditionally prepared using the controller 122. As long as the plating operation continues, the routine of FIG. 3B will be executed repeatedly. Once the routine returns, the substrate temperature is read again and again compared to the lower temperature limit T _L at 136.
At this time, assuming that the base layer temperature is higher than the lower limit temperature, in order to determine whether the base layer temperature is higher than the upper limit temperature T _U , a step 140 is performed.
Another comparison is made at . Assuming that the desired average temperature of the base layer is about 100°C, the upper temperature limit T _U is typically set at about 110°C. If this temperature is exceeded, a signal is provided from the output 134 of the controller 122 to turn off the arc source 105, referenced 142.
It is shown in the section. This moment corresponds to the subsequent edges of the pulses shown in FIG. Once arc source 105 is turned off, the main program is returned via outlet 139. If the substrate temperature T _S is lower than the upper temperature limit T _U , the pulse is maintained in its ON state. What can be seen from the above explanation is that the arc source 1
10 is adapted to generate pulses to maintain the temperature of the substrate at a level appropriate to the type of coating applied thereto, as further discussed in Example 1 below. Other means may be employed to effect pulsing of the arc source. For example, a comparison can be made at 136 to determine whether T _S >T _U. If so, the arc source is turned off. A comparison may then be made at 140 to determine when T _S >T _L. When this occurs, the arc is restarted. Additionally, if a hardware source for generating a pulse train other than the cathode plating method is known, a hardware form may be employed. Furthermore, the nature of the control device provided for maintaining the substrate temperature may vary in other ways from that shown in FIG. 3B. For example, conventional closed-loop control is utilized where the sensed substrate temperature is continuously compared to a desired substrate temperature to generate a continuous error signal that is employed to control the substrate temperature. Good too. Alternatively, if a comparison corresponding to step 136 is made to determine whether said temperature T _S is lower than T _L , a proposal similar to that of FIG. 3B may be adopted. good. If T _S is lower than T _L , the arc is ignited and the source 105 is turned on for a predetermined period of time. upper limit temperature
T _U will not be accepted. Rather, the base temperature T _S is repeatedly compared to the lower temperature T _L. When T _S is again lower than T _L , the arc is turned on again with the source for a predetermined period of time. The arc is initiated within the chamber by an igniter 115. The igniter 115 may be an electromechanical device that contacts the surface of the cathode source with an arc starting wire or a gas discharge ignition system, in which a high voltage gas discharge is performed. , a suitable power source provides a current path between the igniter and the cathode surface. The cathodic arc source is water cooled by special grooves machined into a copper block 111 attached to the back of the cathode or arc source material 102. The action of an electric arc on the surface of the cathode material results in a cathode spot. The cathode spot moves randomly across the surface of the coating source material to form a plasma that applies the coating. Also, the movement of this cathode spot can be controlled with the aid of a suitable magnetic field structure. The items to be coated within the chamber are typically referred to as substrates and are indicated generally at 103, the substrates not being shown in detail. This is because they do not form part of this invention. The coating source of material 102 is typically referred to as the cathode or target. (here,
The target may be disposed on the cathode,
Alternatively, the target may be the cathode. )
The target 102 is the source of the coating flux or plasma for the arc plating process. The source material 102, such as titanium, zirconium, titanium-zirconium, or titanium-aluminum, may be fixed and cylindrical, circular, oval, or square, or any other suitable shape. .
Alternatively, separate targets can be employed for each source material to perform simultaneous plating of the mixed coating system. In operation, the substrate to be coated is chemically cleaned and then loaded onto the rotary workpiece holder 102. The vacuum chamber 100 is then pumped down to the base pressure using the pumping system 101. Next, the base layer or component is cleaned with ions and the arc source 110 is turned on and
By applying a photovoltage bias to the substrate by source 104, it is heated using metal ion bombardment. Next, the arc source 1
10 is pulsed for each different work cycle, and the bias voltage from the source 104 and the arc current source 105 are adjusted according to the critical temperature of the substrate. A reactive gas with appropriate additives is then applied to the gas inlet valve 10 to maintain the chamber pressure between approximately 0.1 and 15.0 microns.
6 and gas array valve 107. The base bias and arc current may be controlled by an automatic process controller driven by preset temperature limits. The resulting hard coating begins to deposit at the set substrate temperature. Typical coating thicknesses ranging from about 0.5 to 5.0 microns are then deposited for decorative applications. Example 1 Typical operating conditions and coating combinations observed for various substrate temperatures are shown in the table, where the ranges on x are for alloys and carbon nitrides are O< varies from
Extended from 0.1 to 0.5. In general, example 10 consists of nine examples in which x is increased in 0.1 increments from 0.1 to 0.9. The above description applies to all examples where an alloy constitutes the target material or a carbon nitride constitutes the coating material and the value of x is stated. Furthermore, the additive was O ₂ or C or a mixture thereof. In this case, natural O ₂
is typically present in the C-added examples, and in this case the amount of additive was in the range of 2 to 7 atomic percent. Typically, the C source is CH ₄
Or it was a gas containing carbon such as C ₂ H ₂ .
The above description applies to all instances where it is stated that the coating material is loaded with additives. The above discussion has been made with respect to the relative alloys, and the amounts of carbon nitrides and additives also apply below, and all other designations regarding "x" as well as in the specification and claims. Applies to additives.

【table】

TABLE From the results in the table it was found that the gloss of the base material was maintained when the thickness of the coating was less than 5 microns. Thicker layers (such as 25 or 50 microns) can also be deposited. With such a layer the gloss (reflectance) of the base layer (base material) cannot be doubled. However, the surface finish can be doubled. Typical layers of the above thickness may constitute several layers, in which case:
The materials of each layer may be the same or different. Figure 4 shows impurity-doped TiN, impurity-doped ZrN, and
It shows the spectrum of light reflectance of a Ti _x Zr _1-x N film. Also shown is the reflectance spectra of the 14k gold film. Therefore, as can be seen, the light reflectance spectra of the films of this invention may be required in US Pat. No. 4,415,521. The various color spectra obtained with different coating systems are shown in the table by way of example.

TABLE It is noted from the results of the table that a wide variety of colors for decorative coatings can be produced. The coating film thickness in all cases was in the range of 0.10 to 5 microns. Regarding TiN, its golden-yellow color is generally rich in green and bronze colors, while the ZrN is a yellow-green color with prominent green. Both TiN and ZrN can be added with _O2 to eliminate green,
And C can be added to increase redness. Therefore, by combining the O ₂ and C additives, the added TiN
Alternatively, with added ZrN, it is possible to control from 10K to 24K. Furthermore, with respect to Ti _x Zr _1-x N, the value of k increases as the value of x increases. Similarly, TiC _x N _1-x and Ti _x Al _1-x N
changes across different colors as the value of x changes. Referring again to FIG. 4, the 14K gold color of the Ti _x Zr _1-x N coating was produced with values of x ranging from about 0.25 to about 0.30. This color was produced by ZrN added with additives of about 1% O ₂ and about 4% C. In this case, all percentages are atomic percentages for all additives mentioned in the specification and claims. The added TiM
The 14K gold color was brought about by the addition of approximately 4% _O2 . Furthermore, the amount of Ti and N is
Non-stoichiometric ratios were met, varying from about 1.15 to about 1.2 atomic ratios for each atom of N.
To achieve a non-stoichiometric film, 0.1~
Reduced nitrogen gas in the 1.0 micron range was employed. For the 10K gold color above, this means that (a) x is approximately
Ti _x Zr _1-x N when varying from 0.15 to about 0.20;
(b) doped ZrN with about 2% O ₂ addition;
and (c) the amount of Ti is about 1.25 to about 1.40 for each N.
Doped TiN with approximately 4% O ₂ addition and 3% C addition when varying the atomic ratio of
It was brought by. Regarding the 24K gold color mentioned above, x is about 0.5 to about
Ti _x Zr _1-x N was adopted when varying up to 0.55. Examples The resistance to abrasion of these coatings was then measured using the pin-on-disc method. In this method, a pin with a load of 500 grams is placed on a rotating coated sample (coated disc) and, assuming there are scratches in said coating, is rotated for 50 revolutions. It was supposed to be observed under an optical microscope at 50x magnification. No scratches appeared in all the hard coatings on the surface. EXAMPLE Figures 5 and 5A show graphs of atomic composition for various coatings for different colors as measured by Electron Spectrometer for Chemical Analysis (ESCA), where Figure 5 shows O ₂ and FIG. 2 is a graph of sputter depth according to the ESCA for C-doped TiN. FIG. The _O2 in the film is
This results from natural levels of _O2 in the system. This natural level also applies to the O ₂ shown in FIG. Various details of the materials, design and construction of the coatings for various embodiments of the invention may be changed without departing from the scope of the invention as claimed.
Further, although the preferred embodiment of the invention is described in connection with an arc coating system, it is also possible to use an arc coating system where material is instantaneously evaporated from the target by an arc that is to be confined within a predetermined area of the target's surface. Needless to say, it is also applicable to other systems such as.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an illustrative cathodic arc plasma plating apparatus used in the present invention. FIG. 2 is a schematic diagram of an illustrative arc source used in the cathodic arc plasma plating apparatus of the present invention. FIG. 3 is a time chart showing an illustrative mission cycle of the arc source of the present invention. FIG. 3A is a block diagram of an illustrative control circuit for use with the arc source of the present invention. FIG. 3B is an illustrative flow diagram of a program that may be employed for the control circuit of FIG. 3A. FIG. 4 shows the reflectance of the film produced by the manufacturing process (method) of the present invention. 5 and 5A are schematic diagrams showing the atomic composition of the coating film produced by the manufacturing process of the present invention. 100...Arc plasma plating device, 1
02...Rotary table, 103...Base layer, 104
... High voltage supply source, 105 ... Power supply source, 10
6...Gas introduction pipe, 107...Valve, 10
8... Shutter, 110... Arc source, 113...
... Restriction ring, 114 ... Anode, 115' ... Coil, 120 ... Control circuit, 122 ... Control device, 128, 130 ... Output section, 132 ... Temperature sensor, 134, 135 ... Output section.

Claims (1)

[Scope of Claims] 1. A method for applying a decorative coating on a base layer, comprising the steps of: preparing a solid target mainly made of zirconium; preparing a decorative component as the base layer; ,Zinc alloy,
providing an anode remote from the base layer; biasing the base layer negatively with respect to the target; and the target being a cathodic arc evaporator. forming an arc between the anode and the target so as to react the evaporated vapor with a gas consisting primarily of nitrogen; applying the reactant as a decorative coating of 0.5 to 5.0 microns thick to depositing on a base layer; and adding an additive selected from the group consisting of O ₂ , C and mixtures thereof to the coating to make the coating consist of ZrN doped with the additive. A method characterized by comprising: 2. The color of the additive-doped ZrN is white, which color varies from about 10k to 24k, depending on the relative proportions of the C and _O2 additives. The method described in Section 1. 3. The method of claim 2, wherein the color is about 10k and the amount of _O2 additive is about 2 atomic percent. 4. The method of claim 2, wherein the color is about 14k, the amount of _O2 additive is about 1 atomic percent, and the C additive is about 4 atomic percent. Method. 5. The method according to claim 1, wherein the color of ZrN to which the additive is added is white. 6. The method of claim 5, wherein the additive is about 5 atomic percent _O2 .