Diamond-like carbon coating with gradient phase change
By introducing a transition layer with a gradient of sp3 and sp2 bond ratios into the diamond-like carbon coating, the problems of internal stress accumulation and poor adhesion were solved, achieving a coating design with high adhesion and toughness, extending service life and optimizing friction performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YANGTZE RIVER DELTA PHYSICS RES CENT CO LTD
- Filing Date
- 2025-05-19
- Publication Date
- 2026-05-01
AI Technical Summary
Existing diamond-like carbon coatings are prone to cracking during use due to accumulated internal stress, resulting in poor adhesion and reduced service life. They are also prone to peeling, especially when temperatures change.
A diamond-like carbon coating design with phase gradient changes is adopted. By setting first and second transition layers with a gradient change in the ratio of sp3 bonds to sp2 bonds between the DLC coating and the GLC coating, and combining them with physical vapor deposition, an alternating three-dimensional and planar structure transition is formed to enhance the bonding force.
It effectively relieves internal stress, improves the adhesion between coatings, extends service life, optimizes the coefficient of friction, and enhances the hardness and wear resistance of the coating.
Smart Images
Figure CN224186242U_ABST
Abstract
Description
A diamond-like coating with phase gradient variation Technical Field
[0001] This utility model belongs to the field of surface coating processing technology, and specifically relates to a diamond-like coating with phase gradient change. Background Technology
[0002] Diamond-like carbon (DLC) coatings are widely used in precision parts, molds, internal combustion engines, and medical devices due to their excellent hardness, wear resistance, and good self-lubricating properties. However, in DLC coatings, sp... 3 While the predominantly hybridized carbon atoms endow it with excellent hardness and wear resistance, they also result in a highly cross-linked three-dimensional network structure. This structural characteristic limits the coating's deformability, causing internal stress to accumulate within the coating, making it prone to cracking and generating significant internal stress. Furthermore, as the thickness of the DLC coating increases, the highly cross-linked three-dimensional network structure further amplifies the coating's internal stress, thus affecting its service life.
[0003] To alleviate internal stress and extend the service life of DLC coatings, a common method is to incorporate a tough interlayer between the DLC layers to reduce and release stress. While the tough interlayer can improve the lifespan of the DLC coating to some extent, the adhesion between the coatings is often poor due to differences in the materials used, and it is easily affected by temperature changes, leading to peeling. Therefore, how to improve the toughness of the DLC coating while simultaneously enhancing the adhesion between the tough interlayer and the DLC coating has become a key research issue. Summary of the Invention
[0004] This invention addresses the problems in the prior art by providing a diamond-like carbon (DLC) coating with a phase gradient, which improves the bonding strength between coatings while relieving internal stress in the DLC coating, resulting in a diamond-like carbon coating with high bonding strength and toughness.
[0005] This invention provides a diamond-like carbon coating with phase gradient change. From at least one side of the substrate outward, it is provided with an underlayer, a DLC coating, and one or more sets of cyclic coatings in sequence. The cyclic coating includes a first transition layer, a GLC coating, a second transition layer, and a DLC coating in sequence from the DLC coating outward.
[0006] As a further embodiment, in the first transition layer, along the direction from the DLC coating to the GLC coating, sp 3 Key and sp 2 The ratio of bonds gradually decreases.
[0007] As a further embodiment, in the second transition layer, along the direction from the GLC coating to the DLC coating, sp 3 Key and sp 2 The ratio of bonds gradually increases.
[0008] As some options, the cyclic coating can be set to 1-10 groups.
[0009] As some preferred options, the cyclic coating can be set in 2 to 10 groups.
[0010] As a further option, the thickness of the substrate is selected from 50-500nm.
[0011] As a further option, the thickness of the DLC coating is selected from 100-1000 nm.
[0012] As some preferred options, the thickness of the DLC coating is selected from 300-800 nm.
[0013] As a further option, the thickness of the first transition layer is selected from 30-300 nm.
[0014] As a further option, the thickness of the GLC coating is selected from 50-500 nm.
[0015] As some preferred options, the thickness of the GLC coating is selected from 80-300 nm.
[0016] As a further option, the thickness of the second transition layer is selected from 30-300 nm.
[0017] As a further option, the diamond-like carbon coating with phase gradient variation is prepared by physical vapor deposition.
[0018] As a further option, the sputtering energy for the underlayer is 600-900eV, the current is 55-80mA, and the sputtering time is 1-15min.
[0019] As a further embodiment, the sputtering energy N1 of the DLC coating is selected from 800-1000 eV, the current D1 is selected from 72-90 mA, and the sputtering time is selected from 30-120 min.
[0020] As a further preferred embodiment, the sputtering energy N1 of the DLC coating is selected from 800-950eV, the current D1 is selected from 72-86mA, and the sputtering time is selected from 45-100min.
[0021] As a further option, the sputtering energy N2 of the GLC coating is selected from 550-750eV, the current D2 is selected from 50-70mA, and the sputtering time is selected from 5-20min.
[0022] As a further option, the sputtering energy N2 of the GLC coating is selected from 600-700eV, the current D2 is selected from 55-65mA, and the sputtering time is selected from 8-20min.
[0023] As a further option, the sputtering energy difference between the DLC coating and the GLC coating is selected from 200eV-400eV, and the current difference is selected from 10-40mA.
[0024] As a further option, the sputtering energy of the first transition layer is selected from N1 to N2eV in descending order, and the sputtering current is selected from D1 to D2mA in descending order.
[0025] As a further option, the sputtering energy of the second transition layer is selected from N1 to N2eV in order of increasing value, and the sputtering current is selected from D1 to D2mA in order of increasing value.
[0026] As a further embodiment, the sputtering energy of the first transition layer is selected from 1eV to 35eV in a decreasing gradient from high to low, the sputtering current is selected from 1 to 10mA in a decreasing gradient from high to low, and the sputtering time per gradient is selected from 0.5 to 4min.
[0027] As some preferred embodiments, the sputtering energy of the first transition layer decreases in a gradient from high to low, ranging from 15eV to 30eV; the sputtering current decreases in a gradient from high to low, ranging from 1 to 3mA; and the sputtering time per gradient is selected from 0.5 to 4 min.
[0028] As a further option, the sputtering energy of the second transition layer is selected from 1eV to 35eV, the sputtering current is selected from 1 to 10mA, and the sputtering time for each gradient is selected from 0.5 to 4min.
[0029] As some preferred embodiments, the sputtering energy of the second transition layer is selected from 15eV to 30eV, the sputtering current is selected from 1 to 3mA, and the sputtering time per gradient is selected from 0.5 to 4min.
[0030] As a further option, the type of substrate is not limited in principle, and technicians can select the appropriate material according to their needs, such as any one of stainless steel, carbon steel, or titanium alloy.
[0031] As a further option, the underlying layer is not limited in principle, and technicians can choose the appropriate underlying layer according to their needs, such as any one of titanium layer, aluminum layer, or chromium layer.
[0032] Compared with the prior art, the present invention has at least the following beneficial effects:
[0033] This invention provides a diamond-like carbon (DLC) coating with a phase gradient, achieved by alternating deposition of a GLC coating with high compatibility to a DLC coating, and by creating an spline between the DLC and GLC coatings. 3 Key and sp 2 The first and second transition layers, with their varying bond ratios, achieve a gradual transition between the three-dimensional and planar structures, avoiding structural chaos at the interface. This also effectively enhances the bonding strength between the DLC and GLC coatings, extending the coating's lifespan. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0035] Figure 1 shows the positions of the rotatable target stage, sample stage, high-energy beam ion source, and low-energy beam ion source when preparing a diamond-like carbon coating with phase gradient changes.
[0036] Figure 2 is a schematic diagram of Example 1;
[0037] Figure 3 is a SEM image of Example 1.
[0038] Among them, 1-substrate; 2-undercoat; 3-DLC coating; 4-first transition layer; 5-GLC coating; 6-second transition layer. Detailed Implementation
[0039] For ease of understanding, the present invention will be described more comprehensively below, and embodiments of the present invention will be given, but this does not limit the scope of the present invention.
[0040] The following are descriptions of terms or words, and unless otherwise defined, all technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains.
[0041] In this article, the term "DLC coating" refers to diamond-like carbon coating, a type of coating composed of carbon elements containing a diamond structure (sp). 3 (bond) and graphite structure (sp) 2 Metastable amorphous coatings with (bonds).
[0042] In this article, the term "GLC coating" refers to a coating applied to a substrate. 2 The coating is composed of amorphous carbon with bonds as the main chemical bond structure.
[0043] This invention provides a diamond-like carbon coating with phase gradient change, as shown in Figure 2. From at least one side of the substrate 1 outward, there are sequentially provided an underlayer 2, a DLC coating 3, and one or more sets of circulating coatings. The circulating coatings from the DLC coating 3 outward sequentially include a first transition layer 4, a GLC coating 5, a second transition layer 6, and the DLC coating 3.
[0044] This invention provides a diamond-like carbon (DLC) coating with a phase gradient. Firstly, an underlayer 2 is formed between the substrate 1 and the DLC coating 3. The presence of the underlayer 2 helps ensure a tight bond between the substrate 1 and the DLC coating 3, preventing the DLC coating 3 from peeling off, thus providing a basis for the application of a cyclic coating. Secondly, the high hardness and high wear resistance of the DLC coating 3 originate from its high sp2 content. 3 Hybrid structures, typically in DLC coatings, sp 3 The bond content can reach 80-90%, while sp 2 The key is only 10-20%, sp 3 Key and sp 2 The higher the proportion of sp bonds, the more compact the tetrahedral structure built from carbon atoms, and the more effectively it can resist external load impacts. Macroscopically, this manifests as higher hardness and better wear resistance in the DLC coating. However, excessively high sp... 3 A low bond ratio leads to reduced coating toughness, resulting in brittle fracture under impact loads. In contrast, sp 2 The planar structure formed by hybrid carbon atoms is relatively loose, and the bonding force between layers is weak, which can effectively alleviate the stress generated by the GLC coating. Therefore, this scheme introduces a GLC coating 5 on the basis of DLC coating 3. On the one hand, the alternating deposition of DLC coating 3 and GLC coating 5 can effectively utilize the high toughness of GLC coating 5 to disperse internal stress and fully release the external stress from external load impact. On the other hand, compared with introducing a material completely different from DLC coating 3, we believe that GLC coating and DLC coating have better compatibility and can effectively alleviate the stress caused by temperature changes, thereby optimizing the service life of DLC coating 3. In order to further optimize the compounding effect between DLC coating 3 and GLC coating 5, this scheme further sets a first transition layer 4 and a second transition layer 6 between DLC coating 3 and GLC coating 5. Among them, the first transition layer 4 contains sp 3 Key and sp 2 The proportion of bonds changes continuously from high to low until it reaches the level of sp in GLC coating 5. 3 Key and sp 2 The proportions of the bonds are equal, and the sp in the second transition layer 6 3 Key and sp 2 The proportion of bonds changes continuously from low to high until it reaches the level of sp in DLC coating 3. 3 Key and sp2 The bond ratios are equal; the first transition layer 4 is disposed between the DLC coating 3 and the GLC coating 5, and the second transition layer 6 is disposed between the GLC coating 5 and the DLC coating 3, by continuously changing the sp... 3 Key and sp 2 The bond ratio allows for a gradual transition between three-dimensional and planar structures of carbon atoms from DLC coating 3 to GLC coating 5 or from GLC coating 5 to DLC coating 3, thus avoiding structural disorder at the interface. Simultaneously, the gradient-continuous first transition layer 4 and second transition layer 6 effectively enhance the bonding force between DLC coating 3 and GLC coating 5, extending the coating's service life. Through the combined action of the undercoat 2, DLC coating 3, and the cyclic coating, this scheme achieves a diamond-like carbon coating with high bonding strength and stability, while fully retaining the hardness and wear resistance of DLC. Furthermore, as shown in Figure 3, the diamond-like carbon coating with phase gradient change proposed in this scheme exhibits a uniform morphology.
[0045] As a further option, the cyclic coating can be set to 1-10 groups.
[0046] As some preferred embodiments, the cyclic coating can be configured with 2 to 10 groups. A cyclic coating with 2 to 10 groups helps to construct a structure with alternating distributions of hard and brittle phases and soft and tough phases, thereby more effectively releasing applied stress when facing external load impacts. This ensures both the hardness and wear resistance of the coating and improves its service life.
[0047] As a further embodiment, the first transition layer 4, along the direction from the DLC coating 3 to the GLC coating 5, sp 3 Key and sp 2 The ratio of bonds gradually decreases.
[0048] As a further embodiment, the second transition layer 6 is positioned along the direction from the GLC coating 5 to the DLC coating 3, sp 3 Key and sp 2 The ratio of bonds gradually increases.
[0049] As a further option, the thickness of the underlayer 2 is selected from 50-500nm.
[0050] As a further option, the thickness of the DLC coating 3 is selected from 100-1000 nm.
[0051] As some preferred options, the thickness of the DLC coating 3 is selected from 300-800 nm.
[0052] As a further option, the thickness of the first transition layer 4 is selected from 30-300 nm.
[0053] As a further option, the thickness of the GLC coating 5 is selected from 50-500 nm.
[0054] As some preferred options, the thickness of the GLC coating 5 is selected from 80-300 nm.
[0055] As a further option, the thickness of the second transition layer 6 is selected from 30-300 nm.
[0056] As a further option, the diamond-like carbon coating with phase gradient variation is prepared by physical vapor deposition.
[0057] As a further option, the sputtering energy for the second layer is 600-900eV, the current is 55-80mA, and the sputtering time is 1-15min.
[0058] As a further option, the sputtering energy N1 of the DLC coating 3 is selected from 800-1000eV, the current D1 is selected from 72-90mA, and the sputtering time is selected from 30-120min. Adjusting these conditions helps to obtain a DLC coating 3 with better hardness, wear resistance, and good adhesion, thus ensuring the performance of the final coating.
[0059] As a further preferred embodiment, the sputtering energy N1 of the DLC coating 3 is selected from 800-950eV, the current D1 is selected from 72-86mA, and the sputtering time is selected from 45-100min. This helps to further optimize the thickness of the DLC coating 3, thereby better improving the hardness of the DLC coating 3 and synergistically releasing stress with the GLC coating 5.
[0060] As a further option, the sputtering energy N2 of the GLC coating is selected from 550-750 eV, the current D2 is selected from 50-70 mA, and the sputtering time is selected from 5-20 min, which helps to promote sputtering. 2 The generation of hybrid carbon atoms fully utilizes the toughness of GLC coating 5 and extends the service life of diamond-like carbon coatings with phase gradient changes.
[0061] As a further option, the sputtering energy N2 of the GLC coating 5 is selected from 600-700eV, the current D2 is selected from 55-65mA, and the sputtering time is selected from 8-20min.
[0062] As a further embodiment, the sputtering energy difference between the DLC coating 3 and the GLC coating 5 is selected from 200eV-400eV, and the current difference is selected from 10-40mA.
[0063] As a further option, the sputtering energy of the first transition layer 4 is selected from N1 to N2 eV in descending order, and the sputtering current is selected from D1 to D2 mA in descending order.
[0064] As a further option, the sputtering energy of the second transition layer 6 is selected from N1-N2eV in order of increasing value, and the sputtering current is selected from D1-D2mA in order of increasing value.
[0065] As a further option, the sputtering energy of the first transition layer 4 is selected from 1eV to 35eV in a gradient from high to low, the sputtering current is selected from 1 to 10mA in a gradient from high to low, and the sputtering time for each gradient is selected from 0.5 to 4min.
[0066] As some preferred embodiments, the sputtering energy of the first transition layer 4 is selected from 15eV to 30eV, the sputtering current is selected from 1 to 3mA, and the sputtering time per gradient is selected from 0.5 to 4min.
[0067] As a further option, the sputtering energy of the second transition layer 6 is selected from 1eV to 35eV in a low-to-high gradient, the sputtering current is selected from 1 to 10mA in a low-to-high gradient, and the sputtering time for each gradient is selected from 0.5 to 4min.
[0068] As some preferred embodiments, the sputtering energy of the second transition layer 6 is selected from 15eV to 30eV, the sputtering current is selected from 1 to 3mA, and the sputtering time per gradient is selected from 0.5 to 4min.
[0069] The optimal sputtering energy, current, and time of the first transition layer 4 and the second transition layer 6 help to further adjust the sputtering parameters in the first transition layer 4 and the second transition layer 6. 3 Key and sp 2 The rate of change in bond ratio makes the transition between three-dimensional and planar structures more natural, thereby improving the adhesion of diamond-like carbon coatings with phase gradient changes and extending their service life.
[0070] As a further option, the type of the substrate 1 is not limited in principle. Technicians can select the appropriate material according to their needs, such as any one of stainless steel, carbon steel, or titanium alloy.
[0071] As a further option, the underlying layer 2 is not limited in principle, and technicians can choose the appropriate underlying layer 2 according to their needs, such as any one of titanium layer, aluminum layer, or chromium layer.
[0072] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0073] The chemical raw materials used in the following examples and comparative examples are all prior art and were obtained commercially. The experimental apparatus and testing equipment used in the following examples and comparative examples are all conventional equipment in the art, and there are no special requirements or limitations.
[0074] Example 1
[0075] S1: Using 1mm thick 304 stainless steel as the substrate, it was first ultrasonically cleaned with alcohol for 10 minutes, followed by ultrasonication twice with deionized water, 15 minutes each time. After drying, it was mounted on the sample stage, and the vacuum was evacuated to 6*10. -4 Pa, filled with argon gas to 3.5*10 Pa. -2 Pa, and set the sample stage rotation speed to 5 rpm, turn on the low-energy beam ion source, set the sputtering energy to 75 eV and the current to 9 mA, sputter for 5 min, then turn off the low-energy beam ion source. Turn on the high-energy beam ion source, use a Ti target as the target material, set the high-energy beam ion source sputtering energy to 800 eV and the current to 72 mA, sputter for 15 min, and obtain a substrate layer with a thickness of 120 nm 2;
[0076] S2: The Ti target was converted to a graphite target, the sputtering energy of the high-energy beam ion source was adjusted to 900 eV, the current was 81 mA, and sputtering was performed for 90 min to obtain a DLC coating with a thickness of 500 nm.
[0077] S3: Then the sputtering energy of 900eV and the current of 81mA were reduced to 700eV and 63mA. Each time the sputtering energy was reduced by 20eV and the current was reduced by 1.8mA and held for 2 minutes. After the reduction was completed, a first transition layer 4 with a thickness of 100nm was obtained. Then it was held for 20 minutes to obtain a GLC coating 5 with a thickness of 80nm.
[0078] S4: Increase the sputtering energy and current to 900eV and 81mA, increasing by 20eV and 1.8mA each time, and hold for 2 minutes. After the increase is completed, a second transition layer 6 with a thickness of 100nm is obtained.
[0079] S5: Sputtering energy is maintained at 900eV, current is maintained at 81mA, deposition is carried out for 90min, and a DLC coating with a thickness of 500nm is obtained.
[0080] Repeat steps S3-S5 twice to obtain a diamond-like coating with a phase gradient change consisting of two sets of first transition layer 4, GLC coating 5, second transition layer 6, and DLC coating 3.
[0081] Example 2
[0082] The preparation method and steps are the same as in Example 1, except that steps S3-S5 are repeated only once to obtain a diamond-like coating with a phase gradient change consisting of a first transition layer 4, a GLC coating 5, a second transition layer 6, and a DLC coating 3.
[0083] Example 3
[0084] The preparation method and steps are the same as in Example 1, except that the sputtering energy for steps S2 and S5 of preparing the DLC coating 3 is selected from 800eV, the current is maintained at 72mA, and the deposition time is 45min.
[0085] Example 4
[0086] The preparation method and steps are the same as in Example 1, except that when preparing the first transition layer 4, the sputtering energy is reduced by 30 eV and the current is 2.7 mA each time; when preparing the second transition layer 6, the sputtering energy is increased by 30 eV and the current is 2.7 mA each time; and in step S3 of preparing the GLC coating 5, the sputtering energy is selected from 720 eV, the current is maintained at 65 mA, and the deposition time is 20 min.
[0087] Example 5
[0088] The preparation method and steps are the same as in Example 1, except that when depositing the GLC coating, the sputtering energy is selected from 600eV, the current is selected from 54mA, and the holding time is 5min.
[0089] Comparative Example 1
[0090] S1: Using 1mm thick 304 stainless steel as the substrate, it was first ultrasonically cleaned with alcohol for 10 minutes, followed by ultrasonication twice with deionized water, 15 minutes each time. After drying, it was mounted on the sample stage. The vacuum was evacuated to 6*10-4 Pa, and argon gas was introduced to 3.5*10-2 Pa. The sample stage rotation speed was set to 5 rpm. The low-energy beam ion source was turned on, and the sputtering energy was set to 75 eV and the current to 9 mA. After sputtering for 5 minutes, the low-energy beam ion source was turned off. The high-energy beam ion source was turned on, using a Ti target as the target material. The sputtering energy of the high-energy beam ion source was set to 800 eV and the current to 72 mA. Sputtering was carried out for 15 minutes to obtain the underlayer 2.
[0091] S2: Change the target material to a graphite target, adjust the high-energy beam ion source energy to 900eV, the current to 81mA, and the sputtering time to 120min.
[0092] Comparative Example 2
[0093] The preparation method and steps are the same as in Example 1, except that the GLC coating 5 is not prepared.
[0094] Comparative Example 3
[0095] The preparation method and steps are the same as in Example 1, except that the first transition layer 4 and the second transition layer 6 are not prepared.
[0096] The specific preparation parameters for the examples and comparative examples are shown in Table 1, and the test results for the examples and comparative examples are shown in Table 2.
[0097] Table 1
[0098]
[0099]
[0100]
[0101] Table 2
[0102]
[0103] As can be observed from Examples 1-5 and Comparative Examples 1-3 in Table 2, the examples as a whole exhibit better interfacial bonding and friction coefficient than the comparative examples. This indicates that the diamond-like carbon coating with phase gradient change proposed in this scheme can effectively release inter-coating stress, improve interfacial bonding between coatings, and optimize the friction coefficient, thereby improving the service life of the diamond-like carbon coating with phase gradient change.
[0104] This scheme first discusses the influence of different coatings on the performance of diamond-like carbon coatings with phase gradient changes. It can be observed from Example 1 and Comparative Example 1 that Comparative Example 1 without a circulating coating is weaker than Example 1 in terms of interfacial bonding force and friction coefficient. This shows that the circulating coating set in this scheme can effectively improve the bonding force between different coatings and prevent coating peeling.
[0105] Furthermore, in Example 1 and Comparative Examples 2 and 3, the role of the transition layer (including the first transition layer 4 and the second transition layer 5) and the GLC coating 5 were discussed. It can be observed that, regardless of the absence of the transition layer or the GLC coating 5, Comparative Examples 2 and 3 exhibited lower interfacial bonding strength than Example 1. This may be because, in diamond-like carbon coatings with phase gradient changes, the presence of the GLC coating 5 helps to effectively mitigate the influence of internal stress and external pressure on coating performance, avoiding peeling due to excessive stress. The gradient change in the transition layer... 3 Key and sp 2 The bond ratio helps to smoothly transition between the three-dimensional and planar structures of carbon atoms, further optimizing the bonding force. Therefore, the absence of any of the above coatings may affect the performance of the ratio.
[0106] In traditional diamond-like carbon (DLC) coatings, different numbers and thicknesses of coating layers can affect coating performance. According to Examples 1 and 2, it can be observed that in this scheme, regardless of whether one or two sets of cyclic coatings are set, Examples 1 and 2 exhibit good friction coefficients and interfacial adhesion. At the same time, when two sets of cyclic coatings are set, Example 1 exhibits better friction coefficients and interfacial adhesion than Example 2. This may be because when two sets of cyclic coatings are set, the alternating GLC coating 5 and DLC coating 3 can effectively release external stress when subjected to external load impact, thereby effectively improving interfacial adhesion and extending the service life of the diamond-like carbon coating with phase gradient changes.
[0107] Examples 1, 3, and 5 discuss the influence of different coating thicknesses on the performance of diamond-like carbon (DLC) coatings with phase gradient changes. We can observe that when the thickness of GLC coating 5 is selected from 80-300 nm and the thickness of DLC coating 3 is selected from 300-800 nm, Example 1 exhibits a better coefficient of friction and interfacial adhesion than Examples 2 and 3. This may be because these thicknesses can better cooperate with other coatings to release stress, thereby improving interfacial adhesion and optimizing the coefficient of friction.
[0108] In Examples 1 and 4, we discussed the effects of the transition layer change rate and thickness on the diamond-like carbon coating with phase gradient changes. Similarly, it can be observed that in Examples 1 and 5, the interfacial adhesion and friction coefficient both showed good performance. This may be because when the transition layer meets the requirements of sputtering energy increasing / decreasing by 15eV-30eV each time, sputtering current increasing / decreasing by 1-3.5mA, and sputtering time selected from 0.5-4min, it helps to form a more natural transition layer, thereby optimizing the interfacial adhesion.
[0109] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions, and variations to the above embodiments within the scope of the present invention. Furthermore, without contradiction, those skilled in the art can combine and integrate different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
Claims
1. A diamond-like carbon coating with phase gradient variation, characterized in that, From at least one side of the substrate (1) outward, a base layer (2), a DLC coating (3) and one or more sets of circulating coatings are provided in sequence. The circulating coatings include a first transition layer (4), a GLC coating (5), a second transition layer (6), and a DLC coating (3) in sequence from the DLC coating (3) outward.
2. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, In the first transition layer (4), along the direction from the DLC coating (3) to the GLC coating (5), sp 3 Key and sp 2 The bond ratio gradually decreases; in the second transition layer (6), along the direction from the GLC coating (5) to the DLC coating (3), sp 3 Key and sp 2 The ratio of bonds gradually increases.
3. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, The circulating coating can be set in 1 to 10 groups; preferably, the circulating coating can be set in 2 to 10 groups.
4. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, The thickness of the underlayer (2) is selected from 50-500nm.
5. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, The thickness of the DLC coating (3) is selected from 100-1000 nm.
6. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, The thickness of the DLC coating (3) is selected to be 300-800nm.
7. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, The thickness of the first transition layer (4) is selected to be 30-300nm.
8. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, The thickness of the GLC coating (5) is selected to be 50-500 nm.
9. The diamond-like carbon coating with phase gradient variation according to claim 1, characterized in that, The thickness of the GLC coating (5) is selected to be 80-300 nm.
10. The diamond-like carbon coating with phase gradient according to claim 1, characterized in that, The thickness of the second transition layer (6) is selected from 30-300 nm.