Functional mechanical component and surface treatment method thereof

Abstract

The invention relates to a method for treating a mechanical component (2, 3) comprising a functional surface (8) made of NiP to be in frictional contact with another functional surface, comprising a step of oxidizing and / or phosphatizing the functional surface in order to artificially form an oxide layer (9) and / or a phosphate layer (10) on the functional surface (8), respectively, the phosphate layer (10) is a Ni phosphate layer or a Zn phosphate layer.

Description

[0001] Technical Field of the Invention

[0002] This invention relates to a mechanical component comprising a functional surface to be in frictional contact with another functional surface during use. It also relates to a method for treating the surface of said component. Technical Background

[0004] Watch movements are designed from the outset to operate with lubrication. This reduces frictional loss and, consequently, the energy required for proper functioning. Lubrication allows them to maintain high timekeeping performance and limits wear. However, oils or greases age due to the wear particles they contain, their oxidation, their migration, and even their evaporation. The environment also plays a role, as temperature alters viscosity properties and hinders the timekeeping operation of the movement. Despite all these drawbacks, watch movements are still lubricated with oils and greases, and these oils and greases have become increasingly efficient.

[0005] The key point in the entire movement chain is the escapement. Although it has been dominated by the Swiss pallet design, which is most prevalent today, for centuries, this escapement requires special attention to lubrication. From applying epillagy to the levers to force the oil to remain in contact to applying lubricant to the escape wheel, everything is done to ensure long-term lubrication and thus ensure timekeeping performance.

[0006] Many lubricants have been developed using different types of oils or to apply a solid coating to this Swiss palletescapement.

[0007] The long-held dream is to eliminate lubrication, especially in escapement mechanisms, which would allow for the eradication of lubrication-related problems.

[0008] One approach is to limit the frictional phase in the escapement. The most outstanding example is the coaxial escapement, which minimizes friction by replacing it with impact, allowing it to operate without oil. Another approach is to change the material of the escapement. Therefore, other types of escapements made of silicon or diamond have been developed to minimize friction. Paired materials in functional assemblies, such as diamond-facing ceramic pairs, have also been developed, enabling the formation of a third lubricant.

[0009] Currently, no mass-produced movements are dry-operation; only movements that can possibly be called "prototypes" have been sold in very limited quantities.

[0010] Therefore, a new solution is still being sought. Invention Overview

[0012] Therefore, the condition of the functional surfaces of mechanical components subjected to friction for several years was analyzed. Tests were conducted on components plated with NiP or made entirely of this material, as NiP is known to improve impact resistance. NiP, or nickel-phosphorus alloy, is a nickel alloy containing 12% phosphorus. It is one of the high-phosphorus alloys. It is non-magnetic and corrosion-resistant. It is hard (350 to 450 HV at the bath outlet) and can also be hardened to 900 HV by heat treatment through the precipitation of Ni3P at the grain boundaries.

[0013] Watch wheels made of electroformed NiP and steel coated with NiP deposits underwent prolonged "movement testing." This "movement testing" is a real-world test that evaluates the suitability of the escapement wheel / escapement fork system over long periods. Some NiP wheels tested without any lubricant performed exceptionally well over six years. After testing was stopped and components were disassembled, these wheels were analyzed to assess the condition of their functional surfaces. Ultra-precise microsections obtained via FIB (Focused Ion Beam) cross-sections were analyzed using SEM (Scanning Electron Microscopy). They revealed a "black layer" of unknown nature, resembling a third body that spontaneously formed during these years of operation. This "black layer" was then characterized by EDX (Energy Dispersive X-ray Spectroscopy) analysis to identify elements; subsequently, it was characterized from the outermost surface to a depth of 150 nanometers by TOF SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) analysis to attempt to determine the chemical bonds present. The results of these analyses show:

[0014] - Elements Ni, P, O, and C were detected.

[0015] - PO3 confirmed - Ni2PO4; O2 - ;PO - Ni2O3 - key.

[0016] The elements and bonds in this "black layer" indicate that the originally present nickel and phosphorus had been drastically oxidized, even forming new molecules such as Ni₂PO₄. This intense oxidation, and the formation of new nickel phosphate molecules, appear to be the reason for the good tribological behavior of the escapement wheel / escapement fork assembly.

[0017] Therefore, the inventors attempted to artificially recreate a process that had occurred naturally over several years in a short period of time. The idea was to use several techniques to induce strong oxidation on the NiP surface, and to reproduce, as simply as possible, a molecule similar to Ni2PO4, namely nickel orthophosphate with the formula Ni3(PO4)2. These two methods, oxidation and phosphate formation, were examined separately and then examined together.

[0018] More specifically, the present invention relates to a method for processing a mechanical component comprising a functional surface made of NiP to be in frictional contact with another functional surface, the method comprising the steps of oxidizing and / or phosphate-modifying the functional surface to artificially form oxide layers and / or phosphate layers, respectively, on the functional surface. According to the invention, the phosphate layer is a Ni phosphate layer, or, as a variant, a Zn phosphate layer, which can also improve tribological properties.

[0019] Several options for performing this oxidation and / or phosphate treatment have been successfully evaluated using a tribometer:

[0020] - Dry oxidation using O2 plasma or purging with an O2 / O3 mixture

[0021] - Ni3(PO4)2 is germinated through a chemical reaction (hydrolysis).

[0022] - Dry oxidation + Ni3(PO4)2 germination,

[0023] - Electrolytic oxidation in an aqueous medium.

[0024] The presence of oxides and phosphates on surfaces composed of NiP results in significant dry tribological gains, achieving stabilization and a lower coefficient of friction compared to untreated NiP, for example, paired with ruby.

[0025] The present invention also relates to a mechanical component comprising a functional surface to be in frictional contact with another functional surface, the NiP functional surface having undergone the above-described treatment method and comprising a layer of Ni or Zn oxide and / or phosphate.

[0026] Another aspect of the invention relates to a functional assembly comprising the aforementioned mechanical component and another mechanical component, the other mechanical component including another functional surface to frictionally contact a functional surface of the mechanical component, the functional assembly being characterized in that the frictional contact is dry.

[0027] Other objects, advantages, and features of the invention will become clearer from the following detailed description with reference to the accompanying drawings. Brief description of the attached diagram

[0029] Figure 1 It is a partial view of a functional assembly including two components, namely the escape wheel and the escape fork bearing, having contact surfaces treated according to the method of the present invention.

[0030] Figure 2 This is a cross-sectional schematic diagram of a functional component processed according to the method of the present invention.

[0031] Figure 3Electron microscope image showing the distribution of Ni3(PO4)2 seed crystals on the sample surface.

[0032] Figure 4 Electron microscope image showing Ni3(PO4)2 seed crystals.

[0033] Figure 5 The dynamic friction coefficient curves of two samples, a NiP / ruby pair with NiP treated by dry oxidation according to the present invention and a NiP / ruby pair without NiP treatment, are shown as a function of travel distance.

[0034] Figure 6 The dynamic friction coefficient curves of two samples, NiP / ruby pairs with NiP treated by Ni3(PO4)2 germination according to the present invention and, as a contrast, NiP / ruby pairs without NiP treatment, are shown as a function of travel distance.

[0035] Figure 7 The dynamic friction coefficient curves of two samples, NiP / ruby pairs with NiP treated by dry oxidation and Ni3(PO4)2 germination according to the present invention and a contrasting NiP / ruby pair without NiP treatment, are shown as a function of travel distance.

[0036] Figure 8 The dynamic friction coefficient curves of a NiP / ruby pair with NiP treated by oxidation in an aqueous medium according to the present invention and a NiP / ruby pair without NiP treatment are shown as a function of travel distance for a sample. Invention Details

[0038] This invention relates to a mechanical component that undergoes friction with another component or one or more functional surfaces or contact surfaces on one or more so-called functional surfaces or contact surfaces. This mechanical component can be used in any system where friction is a concern. These can be applications in automotive parts, electronic devices, etc. More specifically, this can be a component used in the watchmaking industry, particularly a component in a movement. Examples of such components include escapement forks, escapement wheels, mobileaxes, bearings, mainsprings, or gears. The component may contact another component. As an example, in the watchmaking industry… Figure 1The functional assembly 1 shown may include a first component 2 and a second component 3. The first component 2 is the pallet stone 4 of the pallet fork 5, and the second component 3 is the escape wheel 6. More specifically, the pallet stone 4 has a rest plane A and an impact plane B, which mesh with the rest plane C and impact plane D of the teeth 7 of the escape wheel 6. These planes A, B, C, and D are functional surfaces subjected to heavy use and high friction and / or contact levels, requiring the use of special materials to reduce friction. Alternatively, one functional surface of the component may contact another functional surface of the same component. For example, this could be a mainspring formed by a strip, where one face of the mainspring contacts the other face of the mainspring.

[0039] The mechanical component is at least partially made of NiP. This means that at least one or more functional surfaces are made of NiP. The component may be entirely made of NiP, or may contain NiP coatings on at least some of its functional surfaces. Another mechanical component, containing another functional surface to be in frictional contact with the functional surface of the mechanical component, may be made of a material selected from ruby, steel, and NiP treated or untreated according to the method of the present invention.

[0040] According to the present invention, at least the functional surface comprises oxides and / or phosphates. Figure 2 This is a schematic diagram of a functional surface 8 having an oxide layer 9 and a phosphate layer 10. For this purpose, the functional surface is subjected to oxidation and / or phosphate treatment. Figure 2 The examples show oxidation and phosphate treatments.

[0041] Oxidation can be performed by dry oxidation or electrolysis. Dry oxidation can be achieved by atmospheric pressure plasma, vacuum plasma, or thermal oxidation in an oxygen-purged furnace. For example, samples can be oxidized in a vacuum reactor under oxygen plasma or, if the equipment is equipped with an ozone (O3) generator, under O2-O3 blend purging. The oxidation artificially produced by this method is in the form of a thin and very uniform layer with a deeper color than the initial substrate. The resulting conversion layer can be considered isotropic, although this needs further confirmation. Advantageously, the oxide layer has a thickness between 7 and 13 nm, preferably between 8 and 12 nm. This thickness can be measured by ellipsometry using, for example, a SEMILAB SE 2000 spectroellipsometry. Advantageously, the oxide layer has an a value between 2.2 and 3 in the CIELAB color space (according to CIE No. 15, ISO 7724 / 1, DIN 5033 Teil 7, ASTM E-1164). The value of b is between 8 and 12, preferably between 9 and 11. value.

[0042] Phosphating can be performed by germinating phosphate on a NiP substrate. This process involves forming seed crystals that promote good tribology. Preferably, this is nickel orthophosphate (Ni3(PO4)2), which germinates relatively easily. Zinc phosphate (Zn3(PO4)2) can also be germinated.

[0043] Germination involves hydrolysis, specifically the breaking of covalent bonds in an aqueous medium. The principle lies in the merging of nickel in the form of nickel chloride hexahydrate (NiCl2, 6H2O) with phosphate in the form of potassium dihydrogen phosphate (KH2PO4). These two molecules do not react with each other during merging. However, if a hydrolytic agent such as urea (NH2CONH2) is added and the mixture is heated to a certain temperature, typically between 70°C and 100°C, the two molecules decompose according to the following reaction chain to form a third molecule, nickel orthophosphate:

[0044]

[0045] Typically, nickel chloride hexahydrate is in an aqueous solution with a molar concentration of 0.01 to 0.06 M, potassium dihydrogen phosphate is in an aqueous solution with a molar concentration of 0.02 to 0.09 M, and urea is in an aqueous solution with a molar concentration of 0.01 to 0.15 M.

[0046] Nickel orthophosphate germination on NiP. The germination exhibits an average density of 35 seeds per 100 x 100 micrometers. This is shown in... Figure 3 This means there are 0.0035 crystals per square micrometer. The crystals have a leaf-like appearance, forming a petal-like structure. The seed crystals were measured to be approximately 5 to 6 micrometers (see [reference needed]). Figure 4 ), and it adheres strongly to the NiP surface.

[0047] Alternative methods exist for generating nickel orthophosphate (Ni3(PO4)2). The hydrolysis reaction described above requires an energy source. In this case, heat enables the reaction to occur. However, it is conceivable to provide this energy using cold plasma (under reduced pressure or atmospheric pressure) or ultrasonic energy.

[0048] In addition, other reactions lead to the formation of nickel orthophosphate in aqueous or solid media. In this regard, it can be mentioned that:

[0049] - Saifon Kullyakool et al."Determination of kinetic triplet of thesynthesized Ni3(PO4)2_8H2O by non-isothermal and isothermal kinetic methods" (Journal of Thermal Analysis and Calorimetry, February 2014):

[0050] NiSO4 and Na2HPO4 at 90℃ for 1 to 5 days

[0051] NiSO4 (0.5 M) and Na3PO4 (0.5 M) were subjected to 70°C for 1 day.

[0052] In the latter two cases, nickel orthophosphate precipitate is obtained.

[0053] The other two methods are described in the following literature:

[0054] - Ismaël Saaddoune et al. “Synthesis characterization, Electrochemistryand in situ XRD investigation of Ni3(PO4)2as negative electrode material for lithium-ion batteries” (ChemElectroChem 10.1002 / celc.202001065):

[0055] Ni3(PO4)2 was synthesized in solid state using NiO and ammonium phosphate (NH4)2HPO4. These components were mixed (in powder form) and then calcined in stages from 200°C to 900°C in a furnace without gas protection.

[0056] - Lowie Henderick et al. The paper "Plasma enhanced atomic layer deposition of nickel and cobalt phosphate for lithium-ion batteries" (2022, 51, 2059 Dalton Transactions) suggests the use of Nicp2 (cyclopentadienyl-nickel) and TMP (trimethyl phosphate) precursors in O2 plasma at 300 °C.

[0057] Nickel orthophosphate films can also be deposited using ALD (atomic layer deposition) technology. This involves a film rather than a seed crystal.

[0058] Samples were prepared by oxidation and / or phosphate treatment according to the invention, and these samples were subjected to tribological tests.

[0059] Oxidation was performed using vacuum dry oxidation. This was achieved using vacuum plasma treatment. The equipment used was a Denton Discovery PVD / PECVD apparatus. The samples were placed in a vacuum chamber. They were first heated to between 100 and 200°C. A highly plasmagenic Ar gas was introduced into the chamber, where a negative potential varying between 500 and 1000 V was applied to the substrate support. This generated a power varying between 90 W and 380 W in the Denton apparatus used. The pressure was set to 15 microbars. It is typically between 10 and 30 microbars. Ar plasma initiation. The first step was to clean the surface by bombarding it with relatively heavy Ar ions for several minutes. Once the surface was cleaned, Ar was gradually replaced by O2 until a pure oxygen plasma was obtained, which subsequently exhibited a yellow hue. This oxygen plasma generated the desired oxide layer. This high-energy plasma has an electron temperature of approximately 100,000°K. This temperature is not physical; it merely reflects the agitation and strong reactivity of atoms confined within this plasma.

[0060] Approximately 10 experiments were conducted under different conditions, with many parameters set: the pressure in the vacuum chamber and the flow rates of Ar and O2, while other parameters were variable: the applied voltage, the temperature of the chamber, and the residence time of the sample in the chamber.

[0061] In addition, two other experiments were conducted at the ALD Encapsulix facility, which features an ozone generator. This O3 gas is particularly reactive, but also highly unstable and transient. The generator provides an O2 / O3 gas blend, which can be used with or without plasma, and the sample is purged from its chamber, in which a vacuum has been pre-created as in the previous equipment. One experiment was conducted with plasma, risking the destruction of O3 molecules; the other was conducted with a simple chemical purging without plasma.

[0062] Ten tests were conducted on the two devices described above. The tribological results for one sample from each device are given below. One sample, number 36, was tested in the ALD device under O2 / O3 blend chemical purging (plasma-free) for 4 hours. The other sample, number 8, was tested in the PVD device at 150°C and 700 V (172 W) for 15 minutes. Figure 5 ).

[0063] The oxidation process is also carried out in an aqueous medium. Oxidation is achieved through simple electrolysis of water connected to the positive (+) electrode. O2 is subsequently released, as is well known to those skilled in the art. The variable parameters are:

[0064] - Type of solvent

[0065] • Electrolytic degreasing bath (alkaline).

[0066] • 1M KOH solution (alkaline).

[0067] - Anodizing in 0.1 M H3PO4 medium (acid),

[0068] - Impregnation in alkaline, neutral and acidic media (i.e. chemical impregnation).

[0069] The results of the tribological test for sample number 35 are given below. Figure 8 ).

[0070] For phosphate treatment, Ni3(PO4)2 is germinated according to the following scheme:

[0071] - Nickel source: Nickel chloride hexahydrate (NiCl2, 6H2O), dissolved at a ratio of 1,570 mg per 200 cc of water, i.e., a 0.033 M solution.

[0072] - Phosphate source: Potassium dihydrogen phosphate (KH₂PO₄), dissolved at a ratio of 1,794 mg per 200 cc of water, i.e., a 0.066 M solution.

[0073] - Source of hydrolysing agent: Urea (NH2CONH2) dissolved in different proportions:

[0074] • 300 mg / 200 cc water (0.025 M solution)

[0075] • 600 mg / 200 cc water (0.05 M solution)

[0076] • 900 mg / 200 cc water (0.075 M solution)

[0077] • 1200 mg / 200 cc water (0.1 M solution).

[0078] These four concentrations affect the size (length, width, and thickness) of the sheet-like crystals during the seed crystallization process. Then, 1 cc of surfactant (sodium lauryl sulfonate) is added. The sample is pre-washed and then subjected to a temperature of 5 A / dm. 2The samples were then activated by cathodic electrolysis. They were then vertically immersed in the hydrolysis solution. The samples were heated to 90°C, and once the solution reached the correct temperature, the samples were held in the solution for 45 minutes. After this time, the samples were removed, rinsed, and dried.

[0079] The fixed parameters are as follows:

[0080] - Reagent concentrations (NiCl2 0.033 M & KH2PO4 0.066 M).

[0081] - Hydrolysis temperature (90℃).

[0082] The variable parameters are as follows:

[0083] - Hydrolyzing agent concentration,

[0084] - The holding time of the plate-like crystals in the beaker

[0085] - The pH of the solution.

[0086] In addition, several samples were ground with a grinding disc (P4000 or 5 μm) in the hope of creating more germination sites.

[0087] Twenty-four samples were treated. The tribological results are presented below for sample number 15 (treated for 45 minutes at a maximum urea concentration of 0.1 M at pH 4.08) and sample number 14 (treated under the same conditions, but for 30 minutes). Figure 6 ).

[0088] Samples were also prepared by combining these two treatments, preferably first by oxidation followed by phosphate treatment. Some samples underwent the dry oxidation treatment described in Sample 8 above, followed by germination with 750 mg of hydrolysate (urea). It should be noted that, in order to preserve the previously plasma-oxidized surface, electrolytic degreasing prior to germination was performed using anodic degreasing rather than cathodic degreasing.

[0089] Tribological tests were conducted on a Ø2 mm ruby ​​sphere in an alternating linear mode. The test conditions were as follows:

[0090] - Normal force: 1 mN,

[0091] - Maximum sinusoidal velocity: 10 mm / s

[0092] - Amplitude: 4 mm

[0093] - Travel distance: 25 m

[0094] - Condition: Dry.

[0095] The test was conducted by LIGA ( Lithographie Galvanoformung AbformungA baseline consisting of rough NiP disks manufactured using methods such as photolithography, electroforming, and molding is used, and its tribological results show a significant change in the coefficient of friction:

[0096] - Starts on 0.5 and above.

[0097] - The break-in period at 0.5 (Lapping phase at 0.5).

[0098] - Dropped to 0.25,

[0099] - Stable at 0.25, with many peaks.

[0100] All tests were conducted under the same configuration and compared to this benchmark.

[0101] exist Figure 5 As can be seen, dry oxidation makes it possible to stabilize CoF, but it also limits the break-in period of NiP. A significant advantage in CoF gain is observed in oxidation using O2 / O3 purging (sample 36).

[0102] Figure 6 The results show that the germination of Ni3(PO4)2 limits the peak CoF and reduces the dry CoF to 0.15. The CoF decrease is very rapid during startup, thus limiting the break-in period.

[0103] In the case of oxidation in an aqueous medium, Figure 8 The dry CoF level decreased and stabilized at 0.15, indicating a very short break-in period.

[0104] Samples combining these two treatments ( Figure 7 The results showed that the CoF decreased and stabilized at 0.15 during dry germination. Depending on the degree of germination, the most significant effects involved longer or shorter break-in periods, but the CoF at startup was significantly lower than the baseline.

[0105] Colorimetric measurements were also performed on samples oxidized by ALD and on control samples that underwent natural oxidation for several years without accelerated oxidation. The colorimetric values ​​(L) of the polished samples were measured using a KONICA MINOLTA CM-3610A spectrophotometer under the following conditions. a b SCI (including specular reflection) and SCE (excluding specular reflection), 8° tilt angle, 4 mm diameter SAV measurement area. The results are given in the table below.

[0106]

[0107] The color difference between two chips is measured based on ΔE, where ΔE is based on L. a b The value is calculated as follows, where This refers to the value of the reference chip, and This refers to the value of the chip oxidized by the process according to the present invention.

[0108]

[0109] This yields a ΔE of 5.4. It can be concluded that the treated sample is darker relative to the reference sample. Therefore, an oxide layer has formed on the sample surface. This oxide layer was characterized more precisely by elliptic polarization analysis. The thickness of this layer appears to be between 9 and 10 nm. On the other hand, its exponent, between 1.8 and 2, indicates that the layer is not primarily composed of NiO (not corresponding to its exponent of 2.1818), but rather of phosphorus oxides, which does not exclude the presence of small amounts of NiO. Phosphorus trioxide (P₂O₃), phosphorus tetroxide (P₂O₄), or phosphorus pentoxide (P₂O₅) have exponents of approximately 1.82, within the determined range. This is a logical result because the reaction kinetics of NiO are lower than those of phosphates, which are dominant and form more easily and rapidly than NiO.

[0110] In summary, the presence of oxides and phosphates on NiP-based surfaces provides significant dry tribological gains.

Claims

1. A functional assembly (1) comprising a first mechanical component (2, 3) and a second mechanical component, the first mechanical component comprising a first functional surface (8) made of NiP, the second mechanical component comprising a second functional surface to be in frictional contact with the first functional NiP surface (8) of the first mechanical component (2, 3), wherein the first functional NiP surface comprises an oxide layer (9) and / or a phosphate layer (10), the phosphate layer (10) being a Ni phosphate layer or a Zn phosphate layer, and the frictional contact between the first and second mechanical components is dry.

2. The functional assembly (1) according to the preceding claim, characterized in that... At least the second functional surface of the second mechanical component is made of a material selected from ruby, steel and NiP.

3. The functional assembly (1) according to the preceding claim, characterized in that... The second functional NiP surface comprises an oxide layer (9) and / or a phosphate layer (10), wherein the phosphate layer (10) is a Ni phosphate layer or a Zn phosphate layer.

4. The functional assembly according to the preceding claim, characterized in that... The Ni phosphate layer or Zn phosphate layer (10) contains seed crystals.

5. The functional assembly according to the preceding claim, characterized in that... These seed crystals are Ni3(PO4)2 seed crystals.

6. The functional assembly according to any one of the preceding claims, characterized in that... The oxide layer (9) has a thickness between 7 and 13 nm, preferably between 8 and 12 nm.

7. The functional assembly according to the preceding claim, characterized in that... The oxide layer (8) mainly contains phosphorus oxides.

8. The functional assembly according to any one of the preceding claims, characterized in that... The oxide layer (9) in L ,a ,b The color space has an a value between 2.2 and 3. The value of b is between 8 and 12, preferably between 9 and 11. value.

9. The functional assembly according to any one of the preceding claims, characterized in that... It is a component of the watch movement.

10. The functional assembly according to any one of the preceding claims, characterized in that... It is a mechanical component (2, 3) selected from the escape fork bearing (4), escape wheel (6), drive shaft, bearing, mainspring and gear.

11. A method for processing a mechanical component (2, 3) of a functional assembly according to any one of claims 1 to 10, the method comprising the step of oxidizing or phosphate-modifying the functional surface (8) to artificially form an oxide layer (9) and / or a phosphate layer (10) on the functional surface (8), respectively, the phosphate layer (10) being a Ni phosphate layer or a Zn phosphate layer.

12. The processing method according to claim 11, characterized in that... The oxidation step is performed by dry oxidation, by atmospheric pressure plasma, by vacuum plasma, by purging with an O2-O3 blend in the presence or absence of plasma, by heat in a furnace purged with oxygen, or by electrolytic oxidation in an aqueous medium.

13. The processing method according to any one of claims 11 to 12, characterized in that... The phosphate treatment step is performed by ALD deposition to form a phosphate film or by a chemical reaction to form phosphate seed crystals.

14. The processing method according to any one of claims 11 to 13, characterized in that... It includes an oxidation step, followed by a phosphate step.

15. The processing method according to any one of claims 11 to 14, characterized in that... The oxidation step is a dry oxidation process with the following sub-steps: - Heat the mechanical components (2, 3) to between 100 and 200°C, and place the mechanical components (2, 3) on the substrate support in the vacuum chamber. Ar is introduced into the vacuum chamber by applying a negative potential between 500 and 1,000 V to the substrate support.

16. The processing method according to any one of claims 11 to 15, characterized in that... The phosphate step is carried out through a chemical reaction between nickel chloride hexahydrate (NiCl2,6H2O), potassium dihydrogen phosphate (KH2PO4), and urea (NH2CONH2).

17. The processing method according to claim 16, characterized in that... The nickel chloride hexahydrate is in an aqueous solution with a molar concentration of 0.01 to 0.06 M, the potassium dihydrogen phosphate is in an aqueous solution with a molar concentration of 0.02 to 0.09 M, and the urea is in an aqueous solution with a molar concentration of 0.01 to 0.15 M.

Images