Superhard decorative coating and method of making same

Abstract

The present application belongs to the field of decorative coating, and particularly relates to a superhard decorative coating and a preparation method thereof. The superhard decorative coating comprises, from inside to outside, a Ti layer, a CrSi layer, a TiCrSi layer, a TiCrSiN layer and a TiCrSiCN layer. In the multilayer film structure, the Ti layer is a primer layer, the CrSi layer and the TiCrSi layer are transition layers and stress gradient relief layers, and the TiCrSiN layer and the TiCrSiCN layer are steel color decorative layers and functional layers. Compared with a traditional steel color coating, the above five-layer structure has high color brightness and high reflectivity, and the hardness and wear resistance are far greater than those of a base material, and the performance is far superior to that of an existing coating. The superhard decorative coating and the process are particularly suitable for stainless steel shell coating applications of watches, 3C electronic products and the like.

Description

Technical Field

[0001] This invention belongs to the field of decorative coatings, specifically relating to an ultra-hard decorative coating and its preparation method. Background Technology

[0002] Physical vapor deposition (PVD) technology, as a mainstream metal surface treatment technology, has played an increasingly important role in the fields of functional thin films, decorative thin films, and optical thin films. Among them, in the field of decorative thin films, mature industrialized varieties include gold (Ti / TiN / Au), rose gold (Ti / TiN / TiCN / Au-Cu), champagne gold (Ti / TiN / AuAgNi), black (Ti / TIWC / WC), gunmetal (Ti / TiC), blue (Ti / TixOy), red (Ti / TiAl / TiAlN), coffee (Ti / TiN / TiCN), steel (Ti / SS), and chrome (Cr / CrSi).

[0003] In today's increasingly competitive market, coatings on the surfaces of many products, such as Swiss watches, Beidou-based smart wearable devices, and Apple iPhones, not only need to possess decorative properties, such as color uniformity, brightness, and Lab value, but also certain levels of hardness, wear resistance, weather resistance, and fingerprint resistance. Currently, common deposition processes often sacrifice or reduce the product's surface brightness and gloss to achieve both of these requirements. Therefore, there is an urgent need for process optimization to achieve coating effects with better overall performance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide an ultra-hard decorative coating and its preparation method.

[0005] The technical solution adopted in this invention is as follows: an ultra-hard decorative coating, comprising a multilayer film deposited sequentially from the inside to the outside on the surface of a substrate material, wherein the first layer is a Ti layer, the second layer is a CrSi layer, the third layer is a TiCrSi layer, the fourth layer is a TiCrSiN layer, and the fifth layer is a TiCrSiCN layer.

[0006] The method for fabricating the superhard decorative coating as described above is characterized by depositing a multilayer film using magnetron sputtering, comprising the following steps:

[0007] S1. Turn on the Ti target and deposit a Ti layer on the surface of the substrate material as the first layer;

[0008] S2. Turn on the CrSi target and deposit a CrSi layer on the first layer as the second layer;

[0009] S3. Turn on the Ti target and CrSi target, and deposit a TiCrSi layer on the second layer as the third layer;

[0010] S4. Turn on the Ti target and CrSi target, fill with reactive gas N2, and deposit a TiCrSiN layer on the third layer as the fourth layer.

[0011] S5. Turn on the Ti target and CrSi target, and fill with reactive gases N2 and C2H2. Deposit a TiCrSiCN layer on the fourth layer as the fifth layer.

[0012] Preferably, the four pairs of Ti and CrSi targets are arranged diagonally to form a closed magnetic field; and both the Ti and CrSi targets are sputtered using a medium-frequency (40KHz) magnetron sputtering method.

[0013] Preferably, the CrSi target is fabricated using hot isostatic pressing with a Cr:Si ratio of 90:10.

[0014] Preferably, in step S1, Ar working gas is introduced, the gas pressure is maintained at 0.3 to 0.4 Pa, the bias voltage is set to -50 to -100 V, the Ti target is turned on, the target current is 20 to 25 A, and the deposition time is 10 to 15 min to form the first layer.

[0015] Preferably, in step S2, Ar working gas is introduced, the gas pressure is maintained at 0.3 to 0.4 Pa, the bias voltage is set to -50 to -100 V, the CrSi target is turned on, the target current is 20 to 25 A, and the deposition time is 10 to 15 min to form the second layer.

[0016] Preferably, in step S3, Ar working gas is introduced and the pressure is maintained at 0.3-0.4 Pa. At the same time, Ti and CrSi targets are turned on, the target currents are both 20-25 A, and the deposition time is 10-15 min to form the third layer.

[0017] Preferably, in step S4, the working gas Ar and the reaction gas N2 at 50 sccm are introduced, the pressure is maintained at 0.3 to 0.4 Pa, the Ti and CrSi targets are turned on at the same time, the target currents are both at 20 to 25 A, and the deposition time is 10 to 15 min to form the fourth layer.

[0018] Preferably, in step S5, working gas Ar and reactive gases N2 and C2H2 are introduced, with N2 and C2H2 increasing in a gradient. Specifically, N2 increases from an initial 20 sccm at a rate of 1 sccm / min to 60 sccm, and C2H2 increases from an initial 15 sccm at a rate of 1 sccm / min to 55 sccm. The gas pressure is maintained at 0.35–0.45 Pa, and the Ti and CrSi targets are turned on simultaneously. The target currents are both 20–25 A, and the deposition time is 40 min to form the fourth layer.

[0019] Preferably, before step S1, the method further includes: injecting a certain amount of Ar under high vacuum, starting an arc power supply to perform ion cleaning on the substrate material, removing the microparticle layer on the surface of the substrate material and activating its surface to increase the bonding force between the film and the substrate.

[0020] The ultra-hard decorative coating provided by this invention comprises, from the inside out, a Ti layer, a CrSi layer, a TiCrSi layer, a TiCrSiN layer, and a TiCrSiCN layer. In this multilayer film structure, the Ti layer serves as the base layer, the CrSi and TiCrSi layers as transition and stress gradient relief layers, and the TiCrSiN and TiCrSiCN layers as steel-colored decorative and functional layers. Compared to traditional steel-colored coatings, the five-layer structure proposed in this invention not only boasts higher color brightness and reflectivity but also exhibits significantly greater hardness and wear resistance than the substrate material, demonstrating performance far superior to existing coatings. This ultra-hard decorative coating and process are particularly suitable for coating applications on stainless steel casings of watches, 3C electronic products, and other similar devices. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0022] Figure 1 This is a schematic diagram of the coating structure of the present invention;

[0023] Figure 2 This refers to the arrangement of the Ti target and CrSi target inside the furnace body and the introduction of the working gas and reaction gas in this invention;

[0024] Figure 3 This is a schematic diagram of the magnet arrangement and magnetic induction lines inside the magnetron cathodes of the Ti target and CrSi target in this invention;

[0025] Figure 4 This is a schematic diagram of the appearance of an embodiment of the present invention;

[0026] Figure 5 This is a comparison of the Lab value and Vickers hardness of the lining steel sheet and the steel sheet before coating in an embodiment of the present invention;

[0027] In the diagram, 1 is the furnace body; 2 is the rotating frame; 3-1 and 3-2 are Ti targets; 4-1 and 4-2 are CrSi targets; and 5-2 and 5-2 are gas pipes. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] Example 1:

[0030] This embodiment describes the coating preparation process for a saber / watch steel case product, with a liner steel sheet placed in the same furnace to test the coating performance.

[0031] The coating apparatus used in this embodiment is distributed as follows: Figure 2 As shown, the furnace body 1 contains a rotating frame 2, two sets of Ti targets, two sets of CrSi targets, and two gas pipes. The four pairs of Ti and CrSi targets are arranged diagonally to form a closed magnetic field. The rotating frame 2 is located between the Ti and CrSi targets. The two gas pipes are used to introduce N2 and C2H2, respectively. The CrSi targets are manufactured using the hot isostatic pressing method, with a Cr:Si ratio of 90:10.

[0032] The specific process is as follows:

[0033] 1. The substrate material is ultrasonically cleaned, heated and vacuumed in the coating chamber, and kept at a temperature of 200℃.

[0034] 2. In a vacuum of 6*10 -3 Pa, Ar gas is introduced to achieve a pressure of 0.15 Pa, bias voltage -350 V, and the substrate material is ion cleaned by rotating 3 times in a vacuum furnace.

[0035] 3. Introduce working gas Ar, maintain the gas pressure at 0.35 Pa, turn on the Ti target, set the target current to 25 A, and deposit the Ti layer for 15 min.

[0036] 4. Introduce working gas Ar, maintain the gas pressure at 0.35 Pa, turn on the CrSi target, set the target current to 25 A, and deposit the CrSi layer for 15 min.

[0037] 5. Introduce working gas Ar, maintain the gas pressure at 0.35 Pa, and simultaneously turn on the Ti and CrSi targets. The target currents are both 20-25 A, and the deposition time is 10-15 min to deposit the TiCrSi layer.

[0038] 6. Introduce working gas Ar and 50 sccm of reaction gas N2, maintain the gas pressure at 0.35 Pa, and simultaneously turn on the Ti and CrSi targets. The target current is 25 A for both targets. The deposition time is 10-15 min to deposit the TiCrSiN layer.

[0039] 7. Introduce working gas Ar and reactive gases N2 and C2H2, with N2 and C2H2 increasing in a gradient. Specifically, N2 increases from an initial 20 sccm to 60 sccm at a rate of 1 sccm / min, and C2H2 increases from an initial 15 sccm to 55 sccm at a rate of 1 sccm / min. Maintain the gas pressure at 0.40 Pa, and simultaneously turn on the Ti and CrSi targets with a target current of 25 A each. Deposit for 40 min to deposit the TiCrSiCN layer.

[0040] The final product obtained is a steel case for a military knife watch, such as... Figure 4 As shown, the color has high brightness and high reflectivity.

[0041] The Lab values ​​of the steel sheet before and after coating were measured using a Minolta CM-2600D spectrophotometer.

[0042] The surface hardness of the steel sheet before and after coating was tested using a Matsuzawa fully automatic Vickers hardness tester from Japan.

[0043] Comparative Example 1:

[0044] The process of this comparative example is roughly the same as that of Example 1, except that a Cr target is used instead of a CrSi target to prepare the film system No. ①.

[0045] Comparative Example 2:

[0046] The process of this comparative example is roughly the same as that of Example 1, except that Cr:Si=50:50 is used instead of Cr:Si=90:10 to prepare membrane system No. ②.

[0047] Comparative Example 3:

[0048] The process of this comparative example is roughly the same as that of Example 1, except that the sudden increase of N2 and C2H2 replaces the gradient increase, resulting in membrane system No. ③.

[0049] Test results as follows Figure 5 As shown, the five-layer structure film proposed in this invention not only has high color brightness and high reflectivity, but also has hardness and wear resistance that are far superior to other comparative examples.

[0050] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, optical disk, etc.

[0051] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for manufacturing an ultra-hard decorative coating, characterized in that, The deposition of multilayer films using magnetron sputtering includes the following steps: S1. Turn on the Ti target and deposit a Ti layer on the surface of the substrate material as the first layer; S2. Turn on the CrSi target and deposit a CrSi layer on the first layer as the second layer; S3. Turn on the Ti target and CrSi target, and deposit a TiCrSi layer on the second layer as the third layer; S4. Turn on the Ti target and CrSi target, fill with reactive gas N2, and deposit a TiCrSiN layer on the third layer as the fourth layer. S5. Turn on the Ti target and CrSi target, and fill with reactive gases N2 and C2H2. Deposit a TiCrSiCN layer on the fourth layer as the fifth layer. The four pairs of Ti and CrSi targets used are arranged diagonally to form a closed magnetic field; and both the Ti and CrSi targets are sputtered using a 40kHz mid-frequency magnetron sputtering method. The CrSi target was fabricated using hot isostatic pressing with a Cr:Si ratio of 90:

10. In step S5, working gas Ar and reactive gases N2 and C2H2 are introduced, with N2 and C2H2 increasing in a gradient. Specifically, N2 increases from 20 sccm to 60 sccm at a rate of 1 sccm / min, and C2H2 increases from 15 sccm to 55 sccm at a rate of 1 sccm / min. The gas pressure is maintained at 0.35–0.45 Pa, and the Ti and CrSi targets are turned on. The target currents are both 20–25 A, and the deposition time is 40 min to form the fifth layer.

2. The method for manufacturing the ultra-hard decorative coating as described in claim 1, characterized in that, In step S1, Ar working gas is introduced, the gas pressure is maintained at 0.3 to 0.4 Pa, the bias voltage is set to -50 to -100 V, the Ti target is turned on, the target current is 20 to 25 A, and the deposition time is 10 to 15 min to form the first layer.

3. The method for manufacturing the ultra-hard decorative coating as described in claim 1, characterized in that, In step S2, Ar working gas is introduced, the gas pressure is maintained at 0.3 to 0.4 Pa, the bias voltage is set to -50 to -100 V, the CrSi target is turned on, the target current is 20 to 25 A, and the deposition time is 10 to 15 min to form the second layer.

4. The method for manufacturing the ultra-hard decorative coating as described in claim 1, characterized in that, In step S3, Ar working gas is introduced and the pressure is maintained at 0.3-0.4 Pa. At the same time, Ti and CrSi targets are turned on, and the target currents are both 20-25 A. The deposition time is 10-15 min to form the third layer.

5. The method for manufacturing the ultra-hard decorative coating as described in claim 1, characterized in that, In step S4, the working gas Ar and the reaction gas N2 at 50 sccm are introduced, and the gas pressure is maintained at 0.3 to 0.4 Pa. At the same time, the Ti and CrSi targets are turned on, the target currents are both at 20 to 25 A, and the deposition time is 10 to 15 min to form the fourth layer.

6. The method for manufacturing the ultra-hard decorative coating as described in claim 1, characterized in that, Before step S1, the process also includes: filling a certain amount of Ar under high vacuum, starting the arc power supply to perform ion cleaning on the substrate material, removing the microparticle layer on the surface of the substrate material and activating its surface to increase the bonding force between the film and the substrate.

7. The superhard decorative coating prepared by the method for producing the superhard decorative coating according to any one of claims 1-6, characterized in that, It includes a multilayer film deposited sequentially from the inside to the outside on the surface of a substrate material, wherein the first layer is a Ti layer, the second layer is a CrSi layer, the third layer is a TiCrSi layer, the fourth layer is a TiCrSiN layer, and the fifth layer is a TiCrSiCN layer.

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