MXPA98003389A - Article recubie - Google Patents

Abstract

An article is covered with a multilayer coating comprising at least one layer of nickel deposited on the surface of the article, a layer of palladium / nickel alloy deposited on the nickel plate, a refractory metal, preferably zirconium, a layer deposited in the palace / nickel alloy layer, a sandwich layer composed of alternating layers of a refractory metal composite and refractory metal deposited in the refractory metal layer, a layer composed of refractory metal, preferably zirconium nitride, deposited in the sandwich layer, and a layer composed of refractory metal oxide or the reaction products of a refractory metal, oxygen and nitrogen deposited in the composite layer of refractory metal. The coating provides the heat of the polished bronze to the article and also provides protection against abrasion and protection against corrosion.

Description

COATED ARTICLE Description of the Invention Field of the Invention This invention relates to decorative and multilayer coatings for substrates, particularly bronze substrates. BACKGROUND OF THE INVENTION Currently the practice with several bronze articles such as lamps, tripods, candelabra, knobs and door handles, and the like, is first burnish and polish the surface of the article to an intense gloss and then apply a protective organic coating, such as one composed of acrylics, urethanes, epoxies and the like, on this polished surface. Although this system is generally very satisfactory it has the disadvantage that the burnishing and polishing operation, particularly if the article is of a complex shape, is labor intensive. Also, known organic coatings are not always as durable as desired, particularly in outdoor applications where articles are exposed to the elements and ultraviolet radiation. Therefore, it would be very advantageous if the copper articles, or indeed other metal articles could be provided with a coating that would give the article the appearance of intensely polished bronze and also provide resistance to wear and corrosion protection. The present invention provides the coating. Brief Description of the Invention The present invention is directed to a substrate containing a multilayer coating on its surface. More particularly, it is directed to a metallic substrate, particularly bronze, which has deposited on its surface multiple superposed layers of certain specific types of metals or metal compounds. The coating is decorative and also provides resistance to corrosion and wear. The coating provides the appearance of intensely polished bronze. In this way, the surface of an article that has the coating on it, simulates an article of bronze intensely polished. A first layer deposited directly on the surface of the substrate is composed of nickel. The first layer may be monolithic or it may preferably consist of two different layers such as a layer of semi-gloss nickel deposited directly on the surface of the substrate and a layer of glossy nickel superimposed on the semi-gloss nickel layer. Deposited on the nickel layer is a layer comprised of a palladium alloy, preferably palladium / nickel alloy. On the palladium alloy layer is a layer comprised of non-precious refractory metal. On the refractory metal layer there is a sandwich layer composed of a plurality of alternating layers of non-precious refractory metal compound such as a zirconium compound, titanium compound, hafnium compound or tantalum compound, preferably a titanium compound or a zirconium compound such as zirconium nitride or titanium nitride, and a non-precious refractory metal, such as zirconium, titanium, hafnium or tantalum, preferably zirconium or titanium. On the walled layer is a layer composed of a non-precious refractory metal compound, preferably a titanium compound or a zirconium compound such as zirconium nitride or titanium nitride. On the non-precious refractory metal composite layer is deposited an upper layer composed of the reaction products of a non-precious refractory metal, preferably zirconium or titanium, oxygen and nitrogen. The nickel alloy and palladium layers are applied by electrodeposition. Layers of refractory metal such as zirconium, refractory metal compounds such as zirconium and the reaction products of the non-precious refractory metal, oxygen and nitrogen are preferably applied by vapor deposition processes such as ion deposition., deposition by sputtering or cathodic sublimation. BRIEF DESCRIPTION OF THE DRAWINGS The Fiqura 1 is a cross-sectional view of a portion of the substrate having the multilayer coating deposited on its surface. DESCRIPTION OF THE PREFERRED EMBODIMENT The substrate 12 can be any metallic substrate or laminable alloy such as copper, steel, bronze, tungsten, nickel alloys, and the like. In a preferred embodiment the substrate is bronze. The nickel layer 13 is deposited on the surface of the substrate 12 by conventional and known electrodeposition methods. Those methods include using a conventional and well known electrodeposition bath such as, for example, a Watts bath such as the electrodeposition solution. Typically, such well known baths contain nickel sulfate, nickel chloride, and boric acid dissolved in water. All well known and commercially available chloride, sulfamate and fluoroborate electrodeposition solutions can be used. Those baths may optionally include a number of well-known conventional compounds, mostly organic, which function as leveling agents, brighteners, and the like. To produce a specularly bright nickel layer, at least one class I polish and at least one class II polish is added to the electrodeposition solution. Class I brighteners are organic compounds which contain sulfur. Class II polishes are organic compounds which do not contain sulfur. Class II brighteners can also produce leveling and, when added to the electrodeposition bath without sulfur-containing class I brighteners, result in nickel deposits. Class I polishes include alkyl naphthalate and benzenesulfonic acids, benzene, naphthalene di and trisulfonic acids, benzene and naphthalene sulfonamides, and sulfonamides such as saccharin, vinyl and allyl sulfonamides and sulfonic acids. Class II polishes are generally unsaturated organic materials such as, for example, acetylenic or ethylenic alcohols, ethoxylated and propoxylated acetylenic alcohols, coumarins and aldehydes. These Class I and Class II polishes are also known in the art and are commercially available with ease. They are described, inter alia, in U.S. Patent 4,421,611, incorporated herein by reference. The nickel layer 13 can be a monolithic layer composed of, for example, semi-gloss nickel or bright nickel, or it can be a double layer containing, for example, a layer composed of semi-gloss nickel and a layer composed of bright nickel. The thickness in the nickel layer is generally in the range of about 2.5399 μm (100 millionths (0.0001) of an inch) to about 88.8999 μm (3,500 millionths (0.0035) of an inch). As is well known to those skilled in the art before the nickel layer is deposited on the substrate, the substrate must be subjected to acid activation by immersing it in a conventional and well known acid activation bath. In a preferred embodiment, as illustrated in the Figure, the nickel layer 13 is actually composed of two different nickel layers 14 and 16. The layer 14 is composed of semi-gloss nickel, while the layer 16 is composed of bright nickel. This double layer of nickel provides better protection against corrosion to the underlying substrate. The semi-bright sulfur-free plate 14 is deposited directly on the surface of the substrate 12. The substrate 12 containing the semi-gloss nickel layer 14 is then placed in a bright nickel electrodeposition bath and the bright nickel layer 16 is deposited on the semi-gloss nickel layer 14.

The thickness of the semi-glossy nickel layer and glossy nickel layer is an effective thickness to provide at least corrosion protection. Generally, the thickness of the semi-gloss nickel layer is at least about 1.2699 μm (50 millionths (0.00005) of an inch), preferably at least about 2.5399 um (100 millionths (0.0001) of an inch), and most preferable way of at least about 3.8099 μm (150 millionths (0.00015) of an inch). The upper thickness limit is generally not critical and is governed by secondary considerations such as cost. In general, however, a thickness of approximately 38.0999 μm should not be exceeded. (1,500 millionths (0.0015) inch), preferably about 25.3999 μm (1,000 millionths) (0.001) inch), and more preferably about 19.0499 μm (750 millionths (0.00075) inch). The bright nickel layer 16 generally has a thickness of at least about 1.2699 μm (50 millionths (0.00005) of an inch), preferably of at least about 3.1749 μm (125 millionths of an inch). (0.000125) of an inch), and more preferably of at least about 6.3499 μm (250 millionths (0.00025) of an inch). The upper thickness range of the bright nickel layer is not critical and is generally controlled by considerations such as cost. Generally, however, it should not exceed a thickness of approximately 63.4999 μm (2,500 millionths (0.0025) of an inch), preferably of approximately 50.7999 um (2,000 millionths (0.0002) of an inch), and more preferably of approximately 38.0999 μm (1,500 millionths (0.0015) of an inch). The bright nickel layer 16 also functions as a leveling layer, which tends to cover or fill imperfections in the substrate. Deposited on the bright nickel layer 16 is layer 20 composed of a palladium alloy. The palladium alloy layer, preferably, palladium / nickel alloy 20 functions, inter alia, to reduce the galvanic couple between the refractory metal such as the zirconium containing layers such as 22 and the nickel layer. The palladium / nickel alloy layer 20 has a weight ratio of palladium to nickel of about 50:50 to about 95: 5, preferably about 60:40 to about 90:10, and more preferably about 70:30 until approximately 85:15. The palladium / nickel alloy layer can be deposited on the nickel layer by any of the well-known and conventional coating deposition processes including electrodeposition. Palladium electrodeposition processes are well known to those skilled in the art. Generally, they include the use of palladium salts or complexes such as amine and palladium chloride salts, nickel salts such as amine and nickel sulfate, organic brighteners, and the like. Some illustrative examples of palladium / nickel and palladium electrodeposition processes and baths are described in US Pat. Nos. 4,849,303; 4,463,660; 4,416,748; 4,428,820; 4,622,110; 4,552,628; 4,628,165; 4,487,665; 4,491,507; 4,545,869 and 4,699,697, all of which are incorporated herein by reference. The thickness of the palladium alloy layer, preferably palladium / nickel 20 is a thickness which is at least effective to reduce the galvanic couple between the refractory metal such as the zirconium containing layers such as 22 and the nickel layer 16. Generally, this thickness is approximately at least 0.0508 um (2 millionths (0.000002) of an inch), preferably at least approximately 0.1269 μm (5 millionths (0.000005) of an inch), and more preferably from at least about 0.2539 μm (10 millionths (0.00001) of an inch). The upper thickness range is not critical and generally depends on economic considerations. Generally, a thickness of about 2.5399 um (100 millionths (0.0001) inch), preferably about 1.7779 um (70 millionths), should not be exceeded. (0.00007) of an inch), and more preferably of approximately 1.5239 μm (60 millionths (0.00006) of an inch). The weight ratio of palladium to nickel in the palladium-nickel alloy depends, inter alia, on the concentration of palladium (in the form of its salt) and nickel (in the form of its salts, in the electrodeposition bath. concentration or ratio of palladium salt in relation to the concentration of nickel salt in the bath, the higher the palladium ratio in the palladium / nickel alloy, deposited on the palladium alloy layer, preferably palladium / nickel alloy 20 is layer 22 composed of a non-precious refractory metal such as hafnium, tantalum, zirconium or titanium, preferably zirconium or titanium, and most preferably zirconium, layer 22 is deposited on layer 20 by conventional techniques and well known such as vacuum coating, physical vapor deposition such as sputtering or cathodic sublimation and the like. ionic rondellation or cathodic sublimation is described, inter alia, in T. Van Vorous, "Metallization by Ionic Bombardment or Cathodic Sublimation, in a Plane; A Technique of New Industrial Coating ", Solid State Technology, Dec. 1976, pp. 62-66, U. Kapacz and S. Schulz," Industrial Application of Decorative Coatings - Principle and Advantages of the Process of Metallization by Ion Bombardment or Cathodic Sublimation " , Soc. Vac. Coat., Proc. 34th RNA, Techn.Conf., Philadelphia, USA, 1991, 48-61, and U.S. Patent Nos. 4,162,954 and 4,591,418, all of which are incorporated herein by reference. in the ion spray deposition coating, the refractory metal such as the objective zirconium, which is the cathode, and the substrate is placed in the vacuum chamber.The air in the chamber is evacuated to produce vacuum conditions in the chamber. An inert gas, such as Argon, is introduced into the chamber.The gas particles ionize and accelerate towards the target to dislodge zirconium atoms.The target evicted material is then typically deposited as a film. coating layer on the substrate. The layer 22 has a thickness which is generally at least about 0.0063 μm (0.25 millionths (0.00000025) of an inch), preferably of at least about 0.0127 μm (0.5 millionths (0.0000005) of an inch), and more preferably of at least about 0.0254 μm (one millionth (0.0000001) of an inch). The upper thickness range is not critical and generally depends on considerations such as cost. Generally, however, layer 22 should not be thicker than about 1.2699 μm (50 millionths (0.00005) of an inch), preferably about 0.3809 μm (15 millionths (0.000015) of an inch), and preferably of approximately 0.2539 μm (10 millionths (0.00001) of an inch). In a preferred embodiment of the present invention, layer 22 is composed of zirconium and deposited by electrodeposition by ion spray. Deposited on layer 22 is sandwich layer 26 composed of a plurality of alternating layers 28 and 30 of a non-precious refractory metal composite and a non-precious refractory metal. Layer 26 generally has a thickness of about 1.2699 μm (50 millionths (0.00005) of an inch) to about 0.0254 μm (one millionth (0.000001) of an inch), preferably of about 1.0159 μm (40 millionths (0.00004) of an inch) to about 0.0508 μm (two millionths of an inch) (0.000002) of an inch), and more preferably of about 0.7619 μm (30 millionths (0.00003) of an inch) to about 0.0762 μm (three millionths (0.000003) of an inch).

Layers containing non-precious refractory metal compounds include a hafnium compound, a tantalum compound, a titanium compound or a zirconium compound, preferably a titanium compound or a zirconium compound, and more preferably a zirconium compound. These compounds are selected from nitrides, carbides and carbonitrides, with nitrides being preferred. Thus, the titanium compound is selected from titanium nitride, titanium carbide and titanium carbonitride, with titanium nitride being preferred. The zirconium compound is selected from zirconium nitride, zirconium carbide and zirconium carbonitride, with zirconium nitride being preferred. The nitride compounds are deposited by any of the conventional and well-known reactive vacuum deposition methods, including reactive ion spray. Reactive ion spray is generally similar to ion spray, except that a gaseous material is introduced which reacts with the displaced target material introduced into the chamber. Thus, in the case where the layers comprising zirconium nitride 28, the target is composed of zirconium and nitrogen gas, is the gaseous material introduced into the chamber. The layers 28 generally have a thickness of at least about 0.0005 μm (two hundredths of a millionth (0.00000002) of an inch), preferably, of at least 0.0025 μm (one tenth of a millionth (0.0000001) of an inch), and more preferable of at least about 0.0127 μm (five tenths of millionth (0.0000005) of an inch). In general, the layers 28 should not be thicker than about 0.6349 μm (25 millionths (0.000025) of an inch), preferably, about 0.2539 μm (10 millionths (0.000010) of an inch), and more preferably of approximately 0.1269 μm (five millionths (0.000005) of an inch). The alternating layers 30 in the sandwich layer 26 with the non-precious refractory metal composite layers 28 are composed of a non-precious refractory metal as described for layer 22. Preferred metals comprising layer 30 are titanium and zirconium. The layers 30 are deposited by any of the conventional and well-known vapor deposition processes such as the ion spray deposition or electrodeposition processes. The layers 30 have a thickness of at least about 0.0005 μm (two hundredths of millionth (0.00000002) of an inch), preferably, at least 0. 0025 μm (one tenth of millionth (0.0000001) of an inch), and more preferably of at least about 0.0127 μm (five tenths of millionth (0.0000005) of an inch). Generally, the layers 30 should not be thicker than about 0.6349 μm (25 millionths (0.000025) of an inch), preferably, about 0.2539 μm (10 millionths (0.000010) of an inch), and more preferably of approximately 0.1269 μm (five millionths (0.000005) of an inch). The sandwich layer 26 is comprised of alternating layers 28 and 30 which generally serve to, inter alia, reduce the film stress, increase the total hardness of the film, improve the chemical resistance and realign the mesh to reduce pores and limits. of grain that extend through the entire film. The number of alternating layers of metal 30 and metal nitride 28 in sandwich layer 26 is generally an effective amount to reduce stress and improve chemical resistance. Generally, this amount is from about 50 to about two alternating layers 28, 30, preferably from about 40 to about four layers 28, 30, and more preferably, from about 30 to about six layers 28, 30 A preferred method for forming a sandwich layer 26 is by using ion spray electrodeposition to deposit a layer 30 of non-precious refractory metal such as zirconium or titanium followed by reactive ion spray electrodeposition to deposit a layer 28 of refractory metal nitride. not precious such as zirconium nitride or titanium nitride. Preferably, the gaseous nitrogen flow rate is varied (pulsating) during the ion spray electrodeposition between zero (nitrogen gas is not introduced) until the introduction of the nitrogen to a desired value to form alternating multiple layers. , 30, of metal and metal nitride 28 in the sandwich layer 26. The thickness ratio of layers 30 to 28 is at least about 20/80, preferably 30/70, and more preferably, about 40/60. In general, it should not be greater than about 80/20, preferably 70/30, and more preferably 60/40. Deposited on the sandwich layer 26 is the layer 32 composed of a non-precious refractory metal compound, preferably a non-precious refractory metal nitride, carbonitride or carbide. The layer 32 is composed of a hafnium compound, a tantalum compound, a titanium compound or a zirconium compound, preferably a titanium compound or a zirconium compound, and most preferably a zirconium compound. The hafnium compounds, tantalum compounds, titanium compounds and zirconium compounds are selected from nitrides, carbides and carbonitrides. The titanium compound is selected from titanium nitride, titanium carbide, and titanium carbonitride, with titanium nitride being preferred. The zirconium compound is selected from zirconium nitride, zirconium carbonitride, and zirconium carbide, with zirconium nitride being preferred. Layer 32 is deposited on layer 26 by any of the conventional known electrodeposition or deposition processes such as vacuum coating, reactive ion deposition and the like. Reactive ion spray deposition is generally similar to ion spray deposition, except that a reactive gas which reacts with the displaced target material is introduced into the chamber. Thus, in the case where the zirconium nitride comprises layer 32, it is composed of zirconium and nitrogen gas, it is the reactive gas introduced into the chamber. Controlling the amount of nitrogen available to react with zirconium, the color of zirconium nitride can be made similar to bronze of various shades. The layer 32 generally has a thickness of at least 0.0508 μm (2 millionths (0.000002) of an inch), preferably of at least 0.1016 μm (four millionths (0.000004) of an inch), and more preferably of at least 0.1524 μm. (six millionths (0.000006) of an inch). The upper thickness range is generally not critical and depends on considerations such as cost. Generally, a thickness of about 0.7619 μm (30 millionths (0.00003) of an inch), preferably of about 0.6349 μm (25 millionths (0.000025) of an inch), and more preferably of about 0.5079 μm ( 20 millionths (0.000020) of an inch). Zirconium nitride is the preferred coating material since it provides the closest appearance to polished bronze. In one embodiment of the invention, as illustrated in the Figure, a layer 34 composed of the reaction products of a non-precious refractory metal, an oxygen-containing gas, such as oxygen, and nitrogen is deposited on layer 32. The metals that can be used in practice are those which are capable of forming metal oxides, a metal nitride and a metal oxynitride under suitable conditions, for example, using a reactive gas composed of oxygen / nitrogen. The metals can be metals, for example, tantalum, hafnium, zirconium and titanium, preferably titanium and zirconium, and more preferably, zirconium.

The reaction products of metal, oxygen and nitrogen are generally composed of metal oxide, metallic nitride and metallic oxynitride. Thus, for example, the reaction products of zirconium, oxygen and nitrogen generally comprise zirconium oxide, zirconium nitride and zirconium oxynitride. The layer 34 can be deposited by any well-known and conventional deposition technique, including sputtering or reactive cathodic sublimation into a pure target metal or an objective composition of oxides, nitrides and / or metals, reactive evaporation, ion sputtering and assisted ion, ion electrodeposition, molecular beam epitaxy, chemical vapor deposition and deposition of organic precursors in the form of liquids. Preferably, however, the metal reaction products of this invention are deposited by reactive ion spray. In a preferred embodiment, reactive ion spray with oxygen and nitrogen gas are used, being introduced simultaneously. Those metal oxides and metal nitrides including the zirconium oxide and zirconium nitride alloys and their preparation and deposition are conventional and well known are described, inter alia, in U.S. Patent No. 5,367,285, the description of which is incorporated herein by reference. reference. In another embodiment, instead of the layer 34 being composed of the reaction products of the refractory metal, oxygen and nitrogen, it is composed of non-precious refractory metal oxide. The refractory metal oxides of which the layer 34 is composed includes, but is not limited to, hafnium oxide, tantalum oxide, zirconium oxide and titanium oxide, preferably titanium oxide and zirconium oxide, and more preferably zirconium oxide. These oxides and their preparation are conventional and well known. The layer containing the reaction products of the metal, oxygen and nitrogen or metal oxide 34 generally has a thickness at least effective to provide better resistance to acids. Generally this thickness is at least about 0.00127 μm (five hundredths of a millionth (0.00000005) of an inch), preferably of at least about 0.0025 μm (one tenth of a millionth (0.0000001) of an inch), and more preferably of less approximately 0.0038 μm (0.15 millionths (0.00000015) inch). Generally, the metal oxynitride layer should not be thicker than about 0.1269 μm (five millionths (0.000005) of an inch), preferably about 0.0508 μm (two millionths (0.000002) of an inch), and more preferably of approximately 0.0254 μm (one millionth (0.000001) of an inch). For the invention to be more easily understood the following example is provided. The example is illustrative and does not limit the invention of this. EXAMPLE 1 The brass door plates were placed in a conventional dip bath containing the well-known standard soaps, detergents, deflocculants and the like, which was maintained at a pH of 8.9 - 9.2 and at a temperature of 82-93. ° C (180 - 200 ° F) for 30 minutes. The bronze plates were then placed for six minutes in an alkaline, conventional ultrasonic cleaning bath. The ultrasonic cleaning bath had a pH of 8.9-2.2, was maintained at a temperature of about 71-82 ° C (160-180 ° F), and contained conventional and well-known soaps, detergents, deflocculants and the like. After the ultrasonic cleaning the sheets were rinsed and placed in a conventional electronic, alkaline cleaning bath for about two minutes. The cleaning bath, electric, contained an insoluble, submerged steel anode, maintained at a temperature of about 60-82 ° C (140-180 ° F), a pH of about 10.5-11.5, and contained the standard detergents and conventional The sheets were then rinsed twice and placed in a conventional acid activator bath for about one minute. The acid activator bath had a pH of about 2.0 - 3.0, was at room temperature and contained an acid salt based on sodium fluoride. The sheets were then rinsed twice, and placed in an electrodeposition bath of the semi-gloss nickel for about 10 minutes. The semi-gloss nickel bath is a conventional and well-known bath which has a pH of about 4.2-4.6, maintained a temperature of about 54-66 C (130-150 F), contained NiS04, NiCl2, boric acid, and brighteners. A layer of semi-gloss nickel with an average thickness of approximately 6.3499 μm (250 millionths (0.00025) of an inch) was deposited on the surface of the sheet. The sheets containing the semi-gloss nickel layer are rinsed twice and placed in a bright nickel electrodeposition bath for approximately 24 hours. The bright nickel bath is generally a conventional bath which is maintained at a temperature of about 54-66 ° C (130-150 ° F), a pH of about 4.0-4.8, contains NiS04, NiCl2, boric acid, and brighteners . A layer of bright nickel with an average thickness of approximately 19.0499 um (750 millionths (0.00075) inch) is deposited on the semi-gloss nickel layer. The electro-coated plates with semi-glossy and bright nickel were rinsed three times and deposited for approximately four minutes in a conventional palladium / nickel electrodeposition bath. The palladium / nickel electroplating bath was at a temperature of about 29-38 C (85-100 F), a pH of about 7.8-8.5, and uses an insoluble, platinized niobium anode. The bath contains approximately 6-8 grams per liter of palladium (as metal), 2-4 grams per liter of nickel (as metal), NH4C1, wetting agents and brighteners. An alloy of palladium / nickel was deposited (about 80 weight percent palladium and 20 weight percent nickel) having an average thickness of approximately 0.9398 μm (37 millionths (0.000037) inch) was deposited on the palladium layer. After the palladium / nickel layer was deposited, the sheets were subjected to five rinses, including an ultrasonic rinse and dried with hot air. The electrodecoated plates with palladium / nickel were placed in an ion spray electrodeposition vessel. This container is a stainless steel vacuum container marketed by Leybold A.G. from Germany. The container is generally a cylindrical enclosure containing a vacuum chamber, which is adapted to contain a vacuum chamber, which is adapted to be evacuated by means of pumps. An argon source was connected to the chamber by means of an adjustable chamber to vary the flow velocity of the argon towards the chamber. In addition, two nitrogen sources were connected to the chamber by means of an adjustable valve to vary the flow velocity of the nitrogen towards the chamber. Two pairs of magnetron-type target mounts were mounted in a separate space in relation to the chamber and connected to the negative output of the C.D. variable. The objectives constitute the methods and the chamber wall is an anode common to the target cathodes. The objective material was composed of zirconium. A substrate carrier was provided which supported the substrates, i.e., sheets, for example, which can be suspended from the top of the chamber and rotated by means of a variable speed motor to transport the substrates between each pair of magnetron target assemblies. The carrier is conductive and is electrically connected to the negative output of a power supply of C.D. variable. The electrocoated plates are mounted on the carrier of the substrate in the ion spray electrodeposition vessel. The vacuum chamber is evacuated to a pressure of approximately 5 x 10"1 N / m2 (5 x 10" 3 millibars) and heated to approximately 400 ° C via a radiant electric resistance booster. The target material is cleaned by metallization by ionic pumping to remove contaminants from its surface. Ion sputtering cleaning is carried out for about half a minute by applying sufficient energy to the cathodes to achieve a current flow of approximately 18 amps and introducing argon gas at a rate of approximately 200 standard cubic centimeters per minute. A pressure of approximately 3 x 10"1 N / m2 (3 x 10" 3 millibars) is maintained during cleaning by sputter metallization. The sheets are then cleaned by a low pressure etching process. The low-pressure etching procedure is carried out for approximately five minutes and involves applying a potential of C.D. negative, which is increased during a period of one minute from approximately 1200 to approximately 1400 volts to the sheets and applying energy of C.D. to the cathodes to achieve a current flow of approximately 3.6 amps. The gaseous argon was introduced at a rate which was increased over a period of one minute from about 800 to about 1000 standard cubic centimeters per minute, and the pressure maintained at about 1.1 N / m2 (1.1 x 10"2 mbar). The sheets were rotated between the magnetron target assemblies at a rate of revolution per minute.The sheets were then subjected to a high-pressure etching cleaning procedure for approximately 15 minutes. gaseous argon in the vacuum chamber at a rate which was increased over a period of 10 minutes from approximately 500 to 650 standard cubic centimeters per minute (i.e., that at the beginning the flow rate is 500 sccm and ten minutes later the flow speed is 650 sccm and it remains 650 during the rest of the high pressure engraving process), the pressure is maintained at approximately 20 N / m2 (2 x 10"1 millibars), and a negative potential is applied which is increased over a period of ten minutes from approximately 1400 to 2000 volts to the plates The plates are rotated between the magnetron target mounts at about one revolution per minute The pressure in the container is maintained at approximately 20 N / m2 (2 x 10"1 mbar). The sheets are then subjected to another cleaning procedure by etching at low pressure for about five minutes. During this cleaning procedure by low pressure engraving, a negative potential of approximately 1400 volts is applied to the sheets, C.D. to the cathodes to achieve a current flow of approximately 2.6 amps, and argon gas is introduced into the vacuum chamber at a rate which is increased over a period of five minutes from about 800 sccm (standard cubic centimeters per minute) to about 1000 sccm. The pressure is maintained at approximately 1.1 N / m2 (1.1 x 10"2 millibars) and the plates are rotated at approximately one rpm.The target material is cleaned by sputtering or cathodic sublimation again for approximately 1 minute applying sufficient energy to the cathodes to achieve a current flow of approximately 18 amps, introducing argon gas at a rate of approximately 150 sccm, and maintaining a pressure of approximately 3 x 10"1 N / m2 (3 x 10" 3 mbar). cleaning process, protections are interposed between the sheets and the magnetron objective assemblies to avoid the deposition of the objective material on the sheets, the protections are removed and a layer of zirconium having an average thickness of approximately 0.0762 μm (3 millionths of a meter) is deposited. 0.000003) of an inch over the palladium / nickel layer of the sheets over a period of four minutes. Ion sputtering or cathodic sublimation comprises applying energy from C.D. to the cathodes to achieve a current flow of approximately 18 amps, introduce argon gas in a vessel at approximately 450 sccm, maintain the pressure in the vessel at approximately 6 x 10"1 N / m2 (6 x 10" 3 mbar), and spin the plates at approximately 0.7 revolutions per minute. After the zirconium layer is deposited, the sandwich layer of alternating zirconium and zirconium nitride layers is deposited on the zirconium layer. Gaseous argon is introduced from the vacuum chamber at a rate of approximately 250 sccm. C.D. energy is fed. to the cathodes to achieve a current flow of approximately 18 amps. A deviation voltage of approximately 200 volts is applied to the substrates. Gaseous nitrogen is introduced at an initial rate of about 80 sccm. The flow of nitrogen is then reduced to zero or close to zero. This pulsation of nitrogen is set to occur at approximately a 50% duty cycle. The pulse continues for approximately 10 minutes, resulting in a walled pile with approximately six layers of an average thickness of approximately 0.0254 μm (one millionth (0.000001) of an inch). The walled pile has a thickness of approximately 0.1524 μm (six millionths (0.000006) of an inch). After deposition of the sandwich layer of alternating layers of zirconium nitride and zirconium, a layer of zirconium nitride having an average thickness of about 0.2539 μm (10 millionths (0.00001) inch on the walled pile during a period of approximately 20 minutes In this step, the nitrogen is regulated to maintain a partial ionic current of approximately 6.3 x 10-11 amps., the cd energy and the deviation voltage are maintained as before. After completing the deposition of the zirconium nitride layer, a thin layer of the reaction products of zirconium, oxygen and nitrogen having an average thickness of about 0.0063 μm (0.25 millionths (0.00000025) of inch) is deposited over a period of time. of about 30 seconds In this step, the introduction of the argon is maintained at approximately 250 sccm, the cathode current is maintained at approximately 18 amps, the deviation voltage is maintained at approximately 200 volts and the nitrogen flow is set at approximately 80 sccm Oxygen is introduced at a rate of about 20 sccm Although certain embodiments of the invention have been described for purposes of illustration, it should be understood that there are many other embodiments and modifications within the general scope of the invention.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (11)

1. CLAIMS 1. An article comprising a substrate having deposited on at least a portion of its surface a multilayer coating, characterized in that it comprises: a layer composed of semi-gloss nickel; a layer composed of bright nickel; a layer composed of palladium / nickel alloy; a layer composed of zirconium or titanium; a plurality of alternating layers composed of zirconium or titanium and of zirconium compounds or titanium compounds; and a layer composed of a zirconium compound or titanium compound.
2. 2. The article according to claim 1, characterized in that the zirconium or titanium composite layers are composed of zirconium.
3. 3. The article according to claim 2, characterized in that the layers composed of a zirconium compound or a titanium compound are composed of a zirconium compound.
4. 4. The article according to claim 3, characterized in that the zirconium compound is composed of zirconium nitride.
5. 5. The article according to claim 1, characterized in that the substrate is composed of bronze.
6. 6. An article comprising a substrate having on at least a portion of its surface a multilayer coating, characterized in that it comprises: a layer composed of semi-glossy nickel; a layer composed of bright nickel; a layer composed of palladium / nickel alloy; a layer composed of zirconium or titanium; a sandwich layer composed of a plurality of alternating layers composed of titanium or zirconium and of zirconium compounds or titanium compounds; a layer composed of a zirconium compound or a titanium compound; and a layer composed of zirconium oxide or titanium oxide.
7. 7. The article according to claim 6, characterized in that the layers composed of zirconium or titanium are composed of zirconium.
8. 8. The article according to claim 7, characterized in that the layers composed of a zirconium compound or a titanium compound are composed of a zirconium compound.
9. 9. The article according to claim 8, characterized in that the zirconium compound is zirconium nitride.
10. 10. The article according to claim 9, characterized in that the substrate is bronze.
11. 11. The article according to claim 6, characterized in that the substrate is bronze.