WO2020007356A1 - Noble metal product with coating on surface and preparation method therefor - Google Patents

Abstract

Provided are a noble metal product with a coating on the surface and a preparation method therefor. The noble metal product comprises a noble metal base (1) and a physical vapor deposition layer (2) attached to the surface of the noble metal base, wherein the noble metal is gold or silver. The preparation method of the noble metal product comprises: attaching a physical vapor deposition layer (2) to the surface of the noble metal base (1) by adopting physical vapor deposition. The finally prepared noble metal product may have various colors, a film layer is formed stable and is not easy to fall off, and during detection, the surface film layer of the noble metal product will not affect the fineness of the noble metal base.

Description

Precious metal product with surface coating and preparation method thereof Technical field

The invention relates to the field of gold surface plating, in particular to a precious metal product with a plating layer on the surface and a preparation method thereof.

Background technique

Gold products have bright colors and good stability. They are often used as jewelry and are popular with consumers. At present, the production process of gold products mainly includes casting wax, inverted mold, and surface trimming. In order to improve the gloss of the surface of gold products, the surface of gold products is usually treated by electroplating.

CN106521594A discloses a manufacturing method and equipment for processing K gold into a natural color of gold, preparing semi-finished jewelry in advance; electroplating the semi-finished product of jewelry to restore the external color to the natural color of gold; and performing surface treatment on the semi-finished jewelry after plating To form finished jewelry.

However, when the plating method is applied to the surface of the gold product, the film layer on the surface of the gold product is unstable and easily peeled off.

CN107675136A discloses a method for physical vapor deposition (PVD) coating on the surface of a workpiece. The workpiece to be plated is put into a coating chamber to be evacuated and heated, and then argon is passed, and the workpiece to be plated is subjected to ion bombardment. Then, a working gas is passed into the plate to be coated The workpiece is biased to deposit a coating of the corresponding material on the workpiece to be plated.

CN105803412A discloses a PVD coating layer on the surface of an airspeed tube and a preparation method thereof. A single metal plating layer is plated on a polished surface of the airspeed tube substrate by a physical vapor deposition method.

In the above method, a PVD method is used to coat the surface of the workpiece to improve the combining ability of the coating and the workpiece to be plated. However, PVD is currently only suitable for coating on the surface of materials with higher hardness. When coating on the surface of materials with lower hardness (such as Mohs hardness of 2-3), the bonding force between the film layer and the substrate is still weak.

Summary of the invention

The purpose of the present invention is to overcome the problem of unstable plating on the gold surface in the prior art, and to provide a precious metal product with a coating on the surface and a preparation method thereof. Different types of film layers are formed on the surface of the precious metal product of the present invention. The structure of the formed film layer is stable and can show different colors.

In order to achieve the above object, the first aspect of the present invention provides a precious metal product, the precious metal product includes a precious metal substrate and a physical vapor deposition layer attached to a surface of the precious metal substrate, and the precious metal is gold or silver.

A second aspect of the present invention provides a method for preparing a noble metal product, the method comprising: using a physical vapor deposition to attach a physical vapor deposition layer on the surface of the noble metal substrate.

The physical vapor deposition method is used to coat the surface of the noble metal substrate, which can form a colorful layer, and improve the single color of the noble metal substrate. The change of the color will not affect the color of the noble metal substrate. According to a preferred embodiment of the present invention, the surface roughness of the precious metal substrate is between 0.001 μm and 50 μm. After cleaning, it is dried at 100-150 ° C. It is easier to coat the surface of the precious metal substrate by physical vapor deposition, and the formed The film is more stable and has better wear resistance.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic structural diagram of a precious metal product in Embodiment 1;

2 is a schematic structural diagram of a precious metal product in Example 13;

FIG. 3 is a schematic structural diagram of a precious metal product in Example 12. FIG.

Reference Signs

1. Noble metal substrate 2. Physical vapor deposition layer

3.Water plating layer 4. Transparent film layer

detailed description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the end values of each range, between the end values of each range and individual point values, and between the individual point values, one or more new numerical ranges can be obtained by combining each other. These values The scope should be considered to be specifically disclosed herein.

A first aspect of the present invention provides a precious metal product, which comprises a precious metal substrate 1 and a physical vapor deposition layer 2 attached to a surface of the precious metal substrate 1, wherein the precious metal is gold or silver.

Preferably, the content of gold in the precious metal matrix 1 is 33-99.99% by weight, and more preferably 75-99.99% by weight (or 99-99.99% by weight). The silver content is preferably 92.5-99% by weight.

If the precious metal base 1 is gold, it can be K gold or solid gold. The so-called K gold refers to the precious metal base 1 formed by mixing and melting gold with silver, zinc, copper, palladium, or nickel, and the so-called gold refers to the precious metal base 1 having a gold content of not less than 99% by weight. If the noble metal substrate 1 is silver, it can be silver, silver or 925 sterling silver.

The physical vapor deposition method is used to attach a physical vapor deposition layer 2 on the surface of the noble metal substrate 1. The film formed by attaching the physical vapor deposition layer 2 to the noble metal substrate 1 is stable, wear-resistant, and difficult to fade.

Preferably, the thickness of the physical vapor deposition layer 2 is 10 nm-50 μm, and preferably 0.04 μm-2 μm.

Within this thickness range, the bonding between the physical vapor deposition layer 2 and the noble metal substrate 1 is stronger, and when the noble metal products are tested, the physical vapor deposition layer 2 does not affect the color of the noble metal substrate 1 itself.

According to the present invention, the physical vapor deposition layer 2 may be a single plating layer or a multilayer plating layer. For example, physical vapor deposition can be used to deposit the same single plating layer on the entire surface of the noble metal substrate 1. Specifically, the material of the physical vapor deposition layer 2 can be a common metal, alloy, metal oxide, metal nitride, Metal carbide, metal fluoride, metal sulfide, metal boride or diamond-like coating, such as: Ni, Ti, Zn, Cr, Mg, Nb, Sn, Al, In, Fe, Zr, Si, Cu, Ta, Ge, Ag, Co, Au, Gd, La, Y, Ce, W, Hf, Mo, CrN, TiN, TiAlCN, TiCN, TiAlN, AlTiN, TiB ₂ , ZrN, FeCo, AlSi, TiSi, CrSi, ZnAl, TiZn , TiAl, TiZr, TiSi, TiNi, NiAl, NiV, NiFe, gold-copper alloy or DLC, preferably gold-copper alloy.

If the plating layer on the surface of the precious metal substrate 1 is CrN, the precious metal products appear grayish black; if the plating layer on the surface of the precious metal substrate 1 is TiN, the precious metal products develop champagne gold; if the plating on the surface of the precious metal substrate 1 is TiAlN, The color of the noble metal product is brown; if the plating on the surface of the noble metal substrate 1 is DLC, the color of the noble metal product is black.

In addition, in the present invention, a multi-layer plating layer may be deposited on the surface of the noble metal substrate 1 by a physical vapor deposition method, and finally a colorful color is formed. For example, a masking method can be used to cover areas that do not need to be dyed, and then a physical vapor deposition layer 2 is formed on the surface of the precious metal substrate 1, and finally the surface of the precious metal product has different patterns.

Multiple coatings can also be made on the surface of the noble metal substrate 1 in advance, and then a part of the color deposited on the noble metal substrate 1 can be removed by a numerically controlled machine tool or a manual grinding and polishing method. Finally, the surface of the noble metal product can also be formed with patterns of different colors.

According to the present invention, the surface roughness of the precious metal substrate 1 may be 0.001 μm to 50 μm, preferably 0.005 μm to 0.2 μm.

The surface roughness is Ra, that is, the small pitch and unevenness of the small peaks and valleys of the processed surface can be directly tested by a surface roughness measuring instrument. If the raw material of the noble metal substrate 1 itself meets a surface roughness of 0.001 μm to 50 μm, the subsequent steps may be directly performed. If the raw material of the noble metal substrate 1 does not satisfy the surface roughness of 0.001 μm to 50 μm, the noble metal substrate 1 can be treated by a chemical or mechanical method, and the method is not particularly limited as long as it can satisfy the above roughness.

The surface roughness of the noble metal substrate 1 satisfies the above conditions, and it is easier to plate a film on the surface of the noble metal substrate. If the surface roughness is too low, the firmness of the bonding between the film layer and the precious metal substrate is reduced; if the surface roughness is too large, the color of the final precious metal product is affected.

In the present invention, the gloss of the gold product 1 may be 700-900 Gu. In the present invention, Gu means English gloss unit, and 1 gloss unit = 1Gu. When testing the gloss, the gloss gloss of precious metal products was measured with a gloss tester at a 60 ° geometric condition.

According to the present invention, the gold content of the physical vapor deposition layer 2 may be 0.1% by weight or less than 33% by weight. Preferably, the gold content of the physical vapor deposition layer 2 is less than 0.01% by weight or 70-90% by weight. Between, more preferably, the physical vapor deposition layer 2 has a gold content between 0.001-0.008% by weight or between 75-85% by weight.

A second aspect of the present invention provides a method for preparing a noble metal product, the method comprising: using a physical vapor deposition to attach a physical vapor deposition layer 2 on a surface of the noble metal substrate 1.

According to the present invention, the conditions of physical vapor deposition are such that the thickness of physical vapor deposition layer 2 is 10 nm-50 μm (such as 10 nm, 20 nm, 30 nm, 50 nm, 80 nm, 0.1 μm, 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.5 μm , 0.8 μm, 1 μm, 2 μm, 10 μm, 30 μm, 50 μm, or any value between the foregoing values), preferably 0.04 μm to 2 μm.

The physical vapor deposition method is not particularly required, and may be a vacuum evaporation coating, a vacuum sputtering coating, or a vacuum ion plating, and preferably a vacuum ion plating.

If vacuum evaporation coating is used, the vacuum evaporation system is used, and the precious metal substrate 1 and the metal to be plated are both placed in the vacuum evaporation system. The precious metal substrate 1 is heated under the condition of a vacuum of 5-7 × 10 ^-3 Pa, and the material to be plated is placed. In the evaporation boat. The material to be plated can be selected from metal materials (such as aluminum) for color development, and the evaporation voltage is adjusted to heat the evaporation boat to reach the vaporization temperature of the material to be plated, for example, 800-1500 ° C, to achieve coating on the surface of the precious metal substrate 1, and then inert Annealing under the protection of a gas (such as argon).

If vacuum sputtering coating is used, the noble metal substrate 1 is heated at 100-250 ° C. under the conditions of a vacuum of 1 × 10 ^-2 Pa-7 × 10 ^-3 Pa, and the surface oxide film is removed from the target to be plated. Under the condition of plasma, positive ions formed after argon ionization bombarded the target surface, and the surface of the precious metal substrate 1 was coated by magnetron sputtering with a sputtering voltage of 300-700V. The metal to be plated formed a thin film on the surface of the precious metal substrate 1. .

In the present invention, the step of vacuum ion plating includes: placing the noble metal substrate 1 under a vacuum condition, then heating the noble metal substrate 1, starting a metal target, injecting a gas, applying a bias voltage, and coating the surface of the noble metal substrate 1.

Wherein, when the noble metal substrate 1 is left under a vacuum condition, the degree of vacuum is 1 × 10 ^-2 Pa to 7 × 10 ^-3 Pa.

After the gas is injected, the degree of vacuum is 1 × 10 ^-2 Pa to 9.5 × 10 ^-1 Pa.

The temperature will affect the binding force and color of the coating and the noble metal substrate. Especially in the production of rose gold coating, the heating temperature in the furnace is generally 100-250 ° C, preferably 200 ° C.

The coating time is 2-2000min. In the present invention, the deposition time is related to the target and the plating layer. The target is divided into arc target, column target, and flat target. The arc target ion particles are the thickest, followed by flat targets, and the column target ion particles are the most thick. It is thin, so the arc target is colored fast, followed by the flat target, and the column target is colored slowly. Taking rose gold as an example, the coating time of the arc target is about 10min, the coating time of the column target is 20-30min, and the magic color coating time is about 10min. The shortest purple coating time is 2-3min, so the purple color difference of the coating is large and the color is unstable.

The material used for the metal target is selected from nickel, zinc, magnesium, tin, iron, chromium, silicon, copper, titanium, zirconium, molybdenum, tungsten, aluminum, niobium, indium, tantalum, germanium, silver, gold, cobalt, Thallium, lanthanum, yttrium, cerium, thorium, tungsten, gold-copper alloys, stainless steel and its alloys or at least one of oxides, nitrides, carbides, fluorides, sulfides, borides, and preferably gold-copper alloys. In a gold-copper alloy, the atomic ratio of gold to copper is (75-85): (15-25), preferably 85:15 or 75:25.

The gas includes a protective gas and a color tone gas, the protective gas is an inert gas, and the color tone gas is selected from one or more of nitrogen, acetylene, methane, and oxygen; wherein argon is used as the protective gas for adjusting The degree of vacuum, the gas flow of the protective gas may be 20-200 sccm, preferably 20-150 sccm; nitrogen, acetylene, methane or oxygen as the working gas, which can be combined with metal to form a coating film for adjusting the color of the coating layer, the working gas The gas flow is 50-500 sccm.

Among them, the loading bias voltage is 10-150V, and the duty cycle is 10-80%; in the present invention, the "duty cycle" refers to the ratio of the time occupied by the pulse to the total time during a continuous working time. In the present invention, the higher the bias voltage, the greater the brightness, but exceeding a certain value, the edge of the precious metal product will turn yellow; therefore, it is best to limit the loading bias voltage to the above range.

The target current of the metal target is 3-120A for column target, preferably 20-120A, and 50-200A for arc target. In the present invention, the larger the current is, the thicker the ionic particles are, resulting in a more hazy surface coating of precious metal products, that is, the gloss is not good, especially the current of the arc target has the greatest effect on the gloss, and the current of the column target has the greatest effect on the gloss. The degree of influence is slightly worse, and the appropriate current is important for the gloss of the coating. Therefore, it is best to limit the target current to the above range.

The deposition time is related to the shape of the target and the coating layer, which is specifically explained in the examples.

The metal target and protective gas can be selected according to the color displayed by the final precious metal product. It can be a single metal. For example, the selected metal target is a titanium target, the protective gas is argon, the working gas is nitrogen, and the gas flow rate is 100- 350sccm, the final precious metal product is golden yellow. It can also be a mixture of multiple metals. For example, the selected metal target is a titanium aluminum target, the protective gas is argon, the working gas is nitrogen, and the gas flow rate is 100-350 sccm. The color of the final precious metal product is brown. The details are explained in the examples.

According to the present invention, the glow cleaning can be performed before physical vapor deposition, and the conditions for the glow cleaning include: a gas flow of a protective gas of 100-320 sccm, preferably 280-320 sccm, and a loading bias of 380-1000 V, preferably 380- 420V, duty cycle is 10-80%, preferably 48-52%; time is 160-720s, preferably 160-200s.

In the present invention, the method may further include a step of surface-treating the surface of the noble metal substrate 1 so that the surface roughness of the noble metal substrate 1 is 0.001 μm to 50 μm.

The surface treatment method of the noble metal substrate 1 is not particularly limited, and a method of physical grinding or chemical etching may be adopted as long as the condition that the surface roughness of the noble metal substrate 1 is 0.001 μm to 50 μm can be achieved. The surface roughness of the noble metal substrate 1 is 0.001 μm to 50 μm (such as 0.02 μm, 0.05 μm, 0.2 μm, 0.3 μm, 1 μm, or any value between the foregoing values), and preferably 0.005 μm to 0.2 μm.

Preferably, the method further comprises cleaning the precious metal substrate 1 after the surface treatment. The cleaning method is: ultrasonically washing the precious metal substrate 1 at 20-30 kHz for 1-15 min, and / or using 95-98% by weight. Alcohol cleans the surface of the precious metal substrate.

In the present invention, different cleaning methods can be selected according to the surface structure, area, and cleaning degree of the noble metal substrate 1. Generally, there are two ways to clean.

The first type: ultrasonically wash the precious metal substrate 1 under the condition of 20-30kHz for 1-15min; in the present invention, it should be noted that in special cases, the ultrasonic cleaning time can be extended. After the ultrasonic cleaning is completed, the water is washed 6 times. Above, the surface cleaning agent residue is removed. After the cleaning is completed, a drying treatment is required to dehydrate and bake.

The second type: the surface of the precious metal substrate 1 is cleaned, without an oxide layer, and ultrasonic cleaning is not required. The surface of the precious metal substrate 1 can be directly wiped with 95-98% by weight of alcohol.

In the present invention, the cleaning method may be the first or the second method, and preferably, the cleaning method may be the first method or the second method.

The ultrasonic treatment and / or alcohol washing of the precious metal substrate 1 under the above conditions can further improve the binding force between the physical vapor deposition layer 2 and the precious metal substrate 1. In a short period of time, a film layer with a thickness of 10 nm-50 μm can be formed on the surface of the precious metal substrate, and the formed film layer is more stable.

Preferably, the method may further include the step of drying the noble metal substrate 1 after ultrasonic treatment, the drying temperature is 100-150 ° C., and the drying time is 5-30 min.

There is no particular limitation on the method for drying the precious metal substrate, as long as the temperature can be maintained between 100-150 ° C, for example, an oven can be used.

In addition, in order to improve the abrasion resistance and brightness of the physical vapor deposition layer 2, a water plating layer 3 and / or a transparent film layer 4 may also be formed on the surface of the physical vapor deposition layer. That is, the precious metal product of the present invention includes: a precious metal substrate 1 and The physical vapor deposition layer 2 and the water plating layer 3 (shown in FIG. 2) attached to the surface of the precious metal substrate 1 in order, or the precious metal article of the present invention includes: a precious metal substrate 1 and a physical vapor deposition layer sequentially attached to the surface of the precious metal substrate 1 2. The water plating layer 3 and the transparent film layer 4 (as shown in FIG. 3), or the precious metal product of the present invention includes a precious metal substrate 1 and a physical vapor deposition layer 2 and a transparent film layer 4 which are sequentially attached to the surface of the precious metal substrate 1.

The thickness of the water plating layer 3 is 0.05-50 μm, preferably 0.1-1.5 μm. In the present invention, limiting the thickness of the water plating layer 3 to the above range can increase the gloss of the film layer. The material of the water plating layer 3 may be a gold-copper alloy. In the gold-copper alloy, the weight ratio of the content of gold and copper is (75-85): (15-25), preferably 85:15 or 75:25. . The water plating solution in the water plating process is not specifically limited, and can be conventionally selected in the art, for example, a 3G brand gold plating solution, in which the gold trichloride content is 20-25 g / L, potassium pyrophosphate 40-50 g / L, citric acid The salt is 60-80g / L, the additive is 0.2-0.5g / L, and the gold content is 24K. Water plating current is 0.5-0.9A, preferably 0.7-0.8A; temperature is 50-80 ° C, preferably 65-75 ° C; water plating time is 1-5min, preferably 2-3min. In the present invention, the conditions of the water plating are limited to the above range, and the thickness of the water plating layer 3 defined in the present invention can be formed.

The thickness of the transparent film layer 4 is 0.0001-10 μm, preferably 0.0005 to 0.1 μm. The material of the transparent film layer 4 may be a fluoride; for example, the fluoride may be an AF pill; in the present invention, the AF pill Available commercially, for example, AF pills can be purchased from Huizhou Memtech Electronic Technology Co., Ltd., model TS-2AB.

The transparent film layer is made by vacuum evaporation coating, and it is evaporated for 170-190s under the condition of the evaporation source current of 700-750A; and then for 170-190s under the condition of the evaporation source current of 750-800A; Evaporate 410-430s at 800-900A.

In addition, the vacuum evaporation coating was performed at normal temperature, with a vacuum degree of 3 × 10 ^-1 Pa to 6 × 10 ^-1 Pa, an argon flow rate of 50-60 sccm, an oxygen flow rate of 70-80 sccm, and a loading bias of 30-40V. The duty ratio is 30-40% and the time is 20-30min. The targets are aluminum target and silicon target. When aluminum target is used, the current is 2-3A. When silicon target is used, the current is 2-3A.

In the present invention, the thickness and material of the material of the transparent film layer 4 are in the ranges defined above, so that the formed film layer can be made more stable, more resistant to abrasion, and the formed color can be made more durable. fade.

Hereinafter, the present invention will be described in detail through examples.

The detection methods involved in the following examples are as follows:

Gloss: LS192 gloss instrument is used to test the gloss of precious metal products at 60 degrees (angle).

Abrasion resistance: The WS-97 coating adhesion scratch tester developed by Zhongke Kaihua Technology Development Co., Ltd. is used to perform scratch test on precious metal products. The scratch test uses a stylus with a smooth conical tip to characterize the coating surface under gradually increasing load until the coating is damaged. The load applied when the coating is broken is the critical load, and this is used as the adhesion strength of the coating and the substrate. measure. Set the loading rate to 10 N / min, the loading load to 30 N, the scratch speed to 2 mm / min, and the scratch length to 5 mm.

Example 1

This embodiment is to prepare a coffee-colored TiAlN film-plated pure gold product using the method of the present invention, and its structure is shown in FIG. 1.

(1) Pre-treatment

Select precious metal substrate 1: Select gold as precious metal substrate 1 with a surface roughness of 0.02 μm;

Cleaning: Ultrasonic clean the pure gold with distilled water under the condition of 20kHz for 10min, and dry the pure gold at 150 ℃ for 30min after ultrasonic cleaning; then wipe the clean surface with a clean cloth dipped in 98% by weight alcohol;

Vacuum in the furnace: Put the dried gold in a vacuum furnace and adjust the vacuum to 3 × 10 ^-3 Pa to ensure the vacuum environment in the furnace is clean.

(2) Deposition of physical vapor deposition layer 2

Glow cleaning: Glow cleaning is performed under conditions of an argon flow of 300 sccm, a loading bias of 400 V, a duty cycle of 50%, and a time of 400 s.

Adjust the temperature in the furnace to 200 ° C, start the TiAl column target, where the Ti / Al atomic ratio is 7: 3, and the target current is 25A; inject protective gas argon, gas flow rate is 130sccm, and inject nitrogen gas, and the gas flow rate is 150sccm. Adjust the vacuum degree to 3.0 × 10 ^-1 Pa, apply a bias voltage of 100V, a duty cycle of 50%, and deposit for 30 minutes to form a brown TiAlN film with a thickness of 0.3 μm on the surface of pure gold.

Example 2

This embodiment is to prepare a gray-black CrN-plated pure gold product using the method of the present invention.

(1) Pre-treatment

Select precious metal substrate 1: Select pure gold as precious metal substrate 1, whose surface roughness is 0.05 μm;

Cleaning: Pure gold was ultrasonically cleaned with distilled water at 30 kHz for 5 minutes, and the cleaned pure gold was dried at 150 ° C for 30 minutes; then, the surface was cleaned with 98% by weight alcohol;

Vacuum in the furnace: Put the dried gold in a vacuum furnace, adjust the vacuum to 3 × 10 ^-3 Pa, and adjust the temperature in the furnace to 200 ° C.

(2) Deposition of physical vapor deposition layer 2

Glow cleaning: Glow cleaning is performed under conditions of an argon flow of 300 sccm, a loading bias of 400 V, a duty cycle of 50%, and a time of 400 s.

Start a high-purity intermediate frequency chromium arc target with a target current of 100A; inject nitrogen, gas flow is 230sccm, adjust the vacuum to 3 × 10 ^-1 Pa, apply a bias voltage of 100V, a duty cycle of 50%, and deposit for 5 minutes. A gray-black CrN film was formed on the gold surface with a thickness of 0.15 μm.

Example 3

This embodiment is to use the method of the present invention to prepare a black DLC film-plated pure gold product.

(1) Pre-treatment

Select noble metal substrate 1: Pure gold is selected as the noble metal substrate 1, and its surface roughness is 0.2 μm;

Cleaning: Pure gold was ultrasonically cleaned with distilled water at 25 kHz for 10 minutes, and the cleaned pure gold was dried at 150 ° C for 30 minutes; then, the surface was cleaned with 95% by weight alcohol;

Vacuum in the furnace: Put the dried gold in a vacuum furnace and adjust the vacuum to 3 × 10 ^-3 Pa.

(2) Deposition of physical vapor deposition layer 2

Glow cleaning: Glow cleaning is performed under conditions of an argon flow of 300 sccm, a loading bias of 400 V, a duty cycle of 50%, and a time of 400 s.

Adjust the temperature in the furnace to 200 ℃, start the chromium target, the target current is 20A, inject protective gas argon, gas flow is 130sccm, inject acetylene gas, gas flow is 200sccm, load bias 50V, duty cycle is 50%, deposited for 50min, a black film layer with a thickness of 0.5 μm was formed on the surface of pure gold. Then turn off the power of the chrome target column, inject acetylene gas, the gas flow rate is 200 sccm, load the bias voltage 1000V, the duty ratio is 80%, deposit 5h, and form a DLC film on the surface of pure gold with a thickness of 0.1 μm.

Example 4

This embodiment is to prepare a gold-yellow TiN film-plated pure gold product using the method of the present invention.

(1) Pre-treatment

Select noble metal substrate 1: Pure gold is selected as the noble metal substrate 1, and its surface roughness is 0.03 μm;

Cleaning: Pure gold was ultrasonically cleaned with distilled water at 25 kHz for 10 minutes, and the cleaned pure gold was dried at 150 ° C for 30 minutes; then, the surface was cleaned with 98% by weight alcohol;

Vacuum in the furnace: Put the dried gold in a vacuum furnace and adjust the vacuum to 3 × 10 ^-3 Pa to ensure the vacuum environment in the furnace is clean.

(2) Deposition of physical vapor deposition layer 2

Glow cleaning: Glow cleaning is performed under conditions of an argon flow of 300 sccm, a loading bias of 400 V, a duty cycle of 50%, and a time of 400 s.

Start the Ti column target with a target current of 20A. Protective gas argon was injected with a gas flow rate of 130 sccm and nitrogen was injected with a gas flow rate of 200 sccm. The vacuum degree was adjusted to 5 × 10 ^-1 Pa. With a bias voltage of 100V, a duty cycle of 50%, and a deposition time of 30 minutes, a golden yellow TiN film was formed on the surface of pure gold with a thickness of 0.2 μm.

Example 5

This embodiment is to prepare a brown TiAlN film-coated 18K gold gold product using the method of the present invention.

The surface of the gold was plated in the same manner as in Example 1, except that the gold was replaced with 18K gold.

Example 6

This embodiment is to use the method of the present invention to prepare rose gold with reddish pure gold products.

(1) Pre-treatment

Select precious metal substrate 1: Select gold as precious metal substrate 1 with a surface roughness of 0.02 μm;

Cleaning: Ultrasonic clean the pure gold with distilled water under the condition of 20kHz for 10min, and dry the pure gold at 150 ℃ for 30min; then clean the surface with a dust-free cloth dipped in 98% by weight alcohol;

Vacuum in the furnace: Put the dried gold in a vacuum furnace and adjust the vacuum to 3 × 10 ^-3 Pa to ensure the vacuum environment in the furnace is clean.

(2) Deposition of physical vapor deposition layer 2

Glow cleaning: Glow cleaning is performed under conditions of an argon flow of 300 sccm, a loading bias of 400 V, a duty cycle of 50%, and a time of 400 s.

The furnace temperature was adjusted to 200 ° C, and the gold-copper target column target was started. The atomic ratio of gold and copper was 75:25, and the target current was 3A. Protective gas argon was injected, the gas flow rate was 130 sccm, and the vacuum degree was adjusted to 3 × 10 ^-1 Pa. A bias voltage of 100V was applied, the duty ratio was 50%, and the deposition was carried out for 20 minutes to form a reddish-red film layer on the surface of pure gold with a thickness of 0.1 μm.

Example 7

This embodiment is to use the method of the present invention to prepare a rose gold-purple pure gold gold product.

The same method as in Example 6 was used to coat the surface of pure gold, except that the TiAl pillar target was started, wherein the Ti / Al atomic ratio was 7: 3 and the target current was 20A. Protective gas argon was injected, the gas flow rate was 130 sccm, and the nitrogen flow rate was 200 sccm. The vacuum degree was adjusted to 5.0 × 10 ^-1 Pa, the bias voltage was 100 V, the duty ratio was 50%, and the deposition time was 30 minutes. The rose gold-purple film layer has a thickness of 0.3 μm.

Example 8

This embodiment is to use the method of the present invention to prepare purple pure gold gold products.

The same method as in Example 6 was used to coat the surface of pure gold, except that the temperature in the furnace was adjusted to 200 ° C, the Ti target arc target was started, the target current was 100A, and a protective gas, argon was injected, and the gas flow rate was It is 130 sccm, the adjusted vacuum degree is 2.0 × 10 ^-1 Pa, oxygen is injected, the gas flow rate is 100 sccm, the bias voltage is 100 V, the duty ratio is 50%, and the deposition is performed for 3 minutes to form a film with a thickness of 0.1 μm on the surface of pure gold.

Example 9

This embodiment consists in using the method of the present invention to prepare a violet pure gold gold product.

According to the same method as in Example 6, the surface of the gold was plated, except that the temperature in the furnace was adjusted to 260 ° C, and the TiAl target arc target was started, wherein the Ti / Al atomic ratio was 7: 3. The material current is 90A, nitrogen is injected, the gas flow rate is 240 sccm, the vacuum degree is adjusted to 6.0 × 10 ^-1 Pa, the bias voltage is 120V, the duty ratio is 40%, and the deposition is performed for 20 minutes to form a film with a thickness of 0.3 μm on the gold surface.

Example 10

This embodiment consists in using the method of the present invention to prepare champagne gold solid gold products.

According to the same method as in Example 6, the surface of pure gold was plated, except that the temperature in the furnace was adjusted to 200 ° C, the Ti target arc target was started, the target current was 80A, and a protective gas, argon gas was injected, and the gas flow rate was It is 130 sccm, the vacuum degree is adjusted to 3.0 × 10 ^-1 Pa, nitrogen gas is injected, the gas flow rate is 100 sccm, the bias voltage is 80 V, the duty ratio is 60%, and the deposition is performed for 5 minutes to form a film with a thickness of 0.1 μm on the surface of pure gold.

Example 11

This embodiment consists in using the method of the present invention to prepare an iridescent pure gold product.

The same method as in Example 6 was used to coat the surface of pure gold, except that the temperature in the furnace was adjusted to 150 ° C, the Ti target arc target was started, the target current was 100A, and a protective gas, argon was injected, and the gas flow rate It is 130 sccm, the adjusted vacuum degree is 3.0 × 10 ^-1 Pa, oxygen is injected, the gas flow rate is 100 sccm, the bias voltage is 100 V, the duty ratio is 50%, and the deposition is performed for 10 minutes to form a film with a thickness of 0.2 μm on the surface of pure gold.

Example 12

This embodiment is a method for preparing pure gold gold products by using the method of the present invention, and its structure is shown in FIG. 3.

A gold product is prepared according to the method of Example 1, except that a water plating layer 3 and a transparent film layer 4 are further formed on the surface of the physical vapor deposition layer 2.

(1) Pre-treatment

Select precious metal substrate 1: Select gold as precious metal substrate 1 with a surface roughness of 0.02 μm;

Cleaning: Ultrasonic cleaning the distilled gold at 25 kHz using distilled water for 10 minutes, and then wipe the clean surface with a dust-free cloth dipped in 98% by weight alcohol; the cleaned pure gold is dried at 150 ° C for 30 minutes;

Vacuum in the furnace: Put the dried gold in a vacuum furnace and adjust the vacuum to 3 × 10 ^-3 Pa to ensure the vacuum environment in the furnace is clean.

(2) Deposition of physical vapor deposition layer 2

Glow cleaning: Glow cleaning under conditions of argon flow of 300 sccm, loading bias of 400 V, duty cycle of 50%, and time of 400 s;

Then, the temperature in the furnace was adjusted to 200 ° C, and the gold-copper target column target was started. The atomic ratio of gold and copper was 75:25, and the target current was 3A. Protective gas argon was injected, the gas flow rate was 130 sccm, and the vacuum degree was adjusted to 3 × 10 ^-1 Pa. A bias voltage of 100V was applied, the duty ratio was 50%, and the deposition was carried out for 20 minutes to form a reddish-red film layer on the surface of pure gold with a thickness of 0.1 μm.

(3) Water plating 3

Using a water plating process, a water plating layer having a thickness of 0.2 μm is formed under conditions of a water plating current of 0.8 A, a temperature of 70 ° C., and a water plating time of 2 min;

(4) Transparent film layer 4

The solid gold plated with the physical vapor deposition layer 2 and the water plating layer 3 on the surface is placed in a vacuum furnace, and the film is coated by a vacuum evaporation coating method. Adjust the vacuum degree to 2.0 × 10 ^-2 Pa, inject argon gas, the flow rate of argon gas is 60sccm, adjust the vacuum degree to 1.5 × 10 ° Pa, and glow clean for 180s; inject oxygen, oxygen flow rate to 80sccm, adjust the vacuum degree to 4.0 × 10 ^-1 Pa, start the aluminum target 90s and the silicon target 180s, then turn off the power of the aluminum target and the silicon target, start the power of the evaporation source, and the AF pill evaporates for 180s under the condition of the evaporation source current of 720A; then, the evaporation source current is 780A Under the conditions of evaporation for 180 s; and then for 420 s under the condition of an evaporation source current of 850 A, a transparent film layer 4 having a thickness of 0.01 μm is formed.

Example 13

This embodiment is to use the method of the present invention to prepare pure gold products, and its structure is shown in FIG. 2.

A gold product was prepared according to the method of Example 12, except that only the water plating layer 3 was formed on the surface of the physical vapor deposition layer 2.

A water plating process 3 having a thickness of 0.2 μm was formed by using a water plating process under conditions of a water plating current of 0.8 A, a temperature of 70 ° C., and a water plating time of 2 min.

Example 14

This embodiment consists in using the method of the present invention to prepare pure gold products.

A gold product is prepared according to the method of Example 1, except that a transparent film layer 4 is formed on the surface of the physical vapor deposition layer 2.

Place the gold with the physical vapor deposition layer 2 on the surface in a vacuum furnace, and apply vacuum evaporation coating to adjust the vacuum degree to 2.0 × 10 ^-2 Pa. Inject argon, and the flow rate of argon gas is 60 sccm. Adjust the vacuum degree. 1.5 × 10 ° Pa; glow cleaning for 180s, inject oxygen, oxygen flow rate is 80sccm, adjust vacuum degree to 4.0 × 10 ^-1 Pa; start aluminum target 90s, silicon target 180s, then turn off power of aluminum target and silicon target, Start the power source of the evaporation source, the AF pill evaporates for 180s under the condition of the evaporation source current of 720A; then evaporates for 180s under the condition of the evaporation source current of 780A; and then evaporates for 420s under the condition of the evaporation source current of 850A to form a thickness of 0.05 μm fluoride transparent film layer 4.

Example 15

A gold product was prepared according to the method of Example 1, except that the surface roughness of the pure gold was 10 μm.

Example 16

A gold product was prepared according to the method of Example 1, except that the surface roughness of the pure gold was 1 μm.

Example 17

A gold product was prepared according to the method of Example 1, except that the pure gold was ultrasonically cleaned at 5 kHz for 10 minutes.

Example 18

Gold products were prepared according to the method of Example 1, except that the pure gold was ultrasonically cleaned at 50 kHz for 10 minutes.

Example 19

The gold product was prepared according to the method of Example 1, except that the washed gold was not dried.

Comparative Example 1

A gold product was prepared according to the method of Example 1. The difference was that copper plating was performed on copper, the pH of the copper-containing plating solution was 0.1, the plating temperature was 25 ° C, the cathode current density was 4A / dm ² , and the plating was performed for 1 hour. A copper layer having a thickness of 30 μm was formed on the surface of the pure gold.

Comparative Example 2

According to the method of Example 1, an aluminum alloy is used as a substrate, and physical vapor deposition coating is used for the aluminum alloy.

Performance tests were performed on the precious metal products prepared in Examples 1-19 and Comparative Examples 1-2. The specific test results are shown in Table 1.

Table 1

Numbering	Gloss / GU	Abrasion resistance / N
Example 1	853	18.4
Example 2	851	18.8
Example 3	842	20.2
Example 4	821	19.1
Example 5	816	19.9
Example 6	879	17.5
Example 7	865	20.9
Example 8	820	18.5
Example 9	816	20.6
Example 10	812	19.7
Example 11	854	20.2
Example 12	943	26.4
Example 13	895	24.3
Example 14	917	twenty two

Example 15	719	19.4
Example 16	735	18.9
Example 17	754	17.8
Example 18	741	16.4
Example 19	792	16.8
Comparative Example 1	489	13.8
Comparative Example 2	762	15.2

From the results in Table 1, it can be seen that the gold product formed by PVD on the surface of the gold product substrate in the present invention has good surface gloss, and the formed plating layer is stable and not easy to fall off. The film layer formed on the surface of the gold product prepared by the above method is relatively thin and can exhibit different colors.

Examples 20-22

Precious metal products were prepared according to Examples 1-3, except that the precious metal substrate was 925 silver, and the specific performance results are shown in Table 2.

Table 2

Numbering	Film color	Gloss / GU	Abrasion resistance / N
Example 20 (Noble metal substrate is silver)	Brown	855	18.5
Example 21 (Noble metal substrate is silver)	Gray-black	851	18.8
Example 22 (Noble metal substrate is silver)	black	840	19.9

It can be known from the above data that if silver is used as the substrate, under the above conditions, a physical vapor deposition method can be used to plate the surface of silver, and the produced precious metal products can exhibit different colors and can be maintained for a long time without discoloration.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the disclosure of the present invention. All belong to the protection scope of the present invention.

Claims (10)

1. A noble metal product, characterized in that the noble metal product includes a noble metal substrate (1) and a physical vapor deposition layer (2) attached to a surface of the noble metal substrate (1), and the noble metal is gold or silver.
2. The precious metal article according to claim 1, wherein the content of gold in the precious metal matrix (1) is 33-99.99% by weight, preferably 75-99.99% by weight, and the content of silver is 92.5-99% by weight.
3. The precious metal product according to claim 1 or 2, wherein the thickness of the physical vapor deposition layer (2) is 10 nm-50 μm, preferably 0.04 μm-2 μm; and the material of the physical vapor deposition layer (2) is Ni, Ti, Zn , Cr, Mg, Nb, Sn, Al, In, Fe, Zr, Si, Cu, Ta, Ge, Ag, Co, Au, Gd, La, Y, Ce, W, Hf, Mo, CrN, TiN, TiAlCN , TiCN, TiAlN, AlTiN, TiB ₂ , ZrN, FeCo, AlSi, TiSi, CrSi, ZnAl, TiZn, TiAl, TiZr, TiSi, TiNi, NiAl, NiV, NiFe, gold-copper alloy, and DLC Is preferably a gold-copper alloy.
4. The precious metal product according to claim 1 or 2, wherein the surface roughness of the precious metal substrate (1) is 0.001 μm to 50 μm, preferably 0.005 μm to 0.2 μm.
5. A method for preparing a precious metal product according to any one of claims 1-4, characterized in that the method comprises: using a physical vapor deposition to attach a physical vapor deposition layer (2) on the surface of the precious metal substrate (1).
6. The preparation method according to claim 5, wherein the conditions of the physical vapor deposition are such that the thickness of the physical vapor deposition layer (2) is 10 nm to 50 µm.
7. The method according to claim 5, wherein the physical vapor deposition method is a vacuum evaporation coating, a vacuum sputtering coating, or a vacuum ion plating, preferably a vacuum ion plating.
8. The preparation method according to claim 5, wherein the method further comprises surface-treating the surface of the noble metal substrate (1) so that the surface roughness of the noble metal substrate (1) is 0.001 μm-50 μm, preferably 0.005 μm- 0.2 μm.
9. The preparation method according to claim 8, wherein the method further comprises cleaning the noble metal substrate (1) after the surface treatment, and the cleaning method is: ultrasonically washing the noble metal substrate (1) under a condition of 20-30 kHz. 1-15min, and / or use 95-98% by weight of alcohol to clean the surface of the precious metal substrate (1).
10. The preparation method according to claim 9, wherein the method further comprises a step of drying the noble metal substrate (1) after ultrasonic treatment, the drying temperature is 100-150 ° C, and the drying time is 5-30 minutes.

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