Functional mechanical parts and their surface treatment methods

Abstract

The present invention relates to a method for treating mechanical parts (2, 3) having a functional surface (8) made of NiP intended to be in frictional contact with another functional surface, the method comprising the step of oxidizing and / or phosphate-chloriding the functional surface (8) in order to artificially form an oxide layer (9) and / or a phosphate layer (10) on the functional surface (8), the phosphate layer (10) being a layer of nickel phosphate or zinc phosphate.

Description

[Technical Field]

[0001] The present invention relates to a mechanical part that includes a functional surface intended to come into frictional contact with another functional surface during use. It also relates to a method for treating the surface of said part. [Background technology]

[0002] Watch movements were designed from the outset with lubrication in mind to ensure proper function. This reduces friction losses and, consequently, the energy required for normal operation. Lubrication maintains high timekeeping performance and suppresses wear. However, oils and greases are elements that lead to degradation due to the wear particles they contain, their oxidation, migration, and even evaporation. Environmental factors also play a role, as viscosity properties change with temperature, hindering the movement's timekeeping operation. Despite these drawbacks, movements are still lubricated with oils and greases. Nevertheless, their performance is constantly improving.

[0003] The escapement is a crucial part of the movement's overall kinetic chain. The Swiss lever escapement, the most common today, has been dominant for centuries, but this escapement requires special attention to lubrication. From the epilam applied to the lever to maintain oil contact, to the application of lubricant to the escape wheel, every measure is taken to ensure long-term lubrication and, consequently, accurate timekeeping.

[0004] Numerous lubricants have been developed, taking into account the use of various types of oils or the thick plating applied to this Swiss-type escapement.

[0005] For some time now, the ultimate goal has been to eliminate lubrication, particularly in escapements, as this is believed to eradicate lubrication-related problems.

[0006] One approach is to suppress friction in the escapement. The most notable example is the coaxial escapement, which minimizes friction by replacing it with impact, thereby enabling it to function without oil. Another approach is to change the material of the escapement. Therefore, different types of escapements using silicon or diamond have been developed to minimize friction. Combinations of materials in functional assemblies have also been developed, such as the combination of diamond-coated ceramic, which allows for the formation of a third lubricant.

[0007] Currently, there are no mass-produced movements that function as dry-type movements; only a very limited number of movements that could be called "prototypes" are available on the market. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] Saifon Kullyakool et al.,Determination of kinetic triplet of the synthesized Ni3(PO4)2_8H2O by non-isothermal and isothermal kinetic methods,Journal of Thermal Analysis and Calorimetry,Feb 2014 [Non-Patent Document 2] Ismael Saaddoune et al.,Synthesis characterization,Electrochemistry and in situ XRD investigation of Ni3(PO4)2 as negative electrode material for lithium-ion batteries,ChemElectroChem 10.1002 / celc.202001065 [Non-Patent Document 3] Lowie Henderick et al.,Plasma enhanced atomic layer deposition of nickel and cobalt phosphate for lithium-ion batteries,Dalton Transactions,2022,51,2059 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] Therefore, new solutions are still being sought. [Means for solving the problem]

[0010] For this purpose, we conducted a functional surface condition analysis of machine parts that had been subjected to friction for several years. The tests were performed on parts plated with NiP, or parts made solely of this material, because NiP is known to improve impact resistance. NiP, or nickel-phosphorus, is a nickel alloy containing 12% phosphorus. It is one of the high-phosphorus alloys, non-magnetic, and corrosion-resistant. It is hard (350-450 HV immediately after plating) and can be hardened up to 900 HV by heat treatment, which causes Ni3P deposition at the grain boundaries.

[0011] Long-term "operational testing" was conducted on watch gears made of electroformed NiP and steel coated with NiP deposits. "Operational testing" refers to testing under actual usage conditions, allowing for long-term evaluation of the suitability of the escape wheel / pallet fork mechanism. Some NiP gears tested without lubricant showed extremely good performance over six years. After the test, the components were disassembled, and the gears were analyzed to evaluate the condition of the functional surfaces. SEM (scanning electron microscopy) analysis of ultra-precise thin sections obtained by FIB (focused ion beam) cutting revealed a "black layer" with unknown properties similar to a third body, which appeared to have formed spontaneously during the years of operation. Next, this "black layer" was characterized by EDX (energy-dispersive X-ray spectroscopy) analysis, and its elements were identified. Subsequently, TOF SIMS (time-of-flight secondary ion mass spectrometry) was used to characterize the layer down to a depth of 150 nm from the surface to identify the existing chemical bonds. The following can be seen from these analytical results. - The elements Ni, P, O, and C were detected. - PO3 - Ni2PO4;O2 - ;PO - Ni2O3 - The binding was identified.

[0012] These elements and the bonds constituting this "black layer" indicate that the originally present nickel and phosphorus were significantly oxidized, forming new molecules such as Ni2PO4. This intense oxidation, coupled with the formation of new nickel phosphate molecules, is thought to be a factor in the favorable tribological behavior of the escape wheel / anchor assembly.

[0013] Therefore, the inventors aimed to artificially reproduce in a short period of time what had occurred naturally over several years. The concept was to vigorously oxidize the NiP surface using multiple techniques and reproduce a molecule similar to Ni2PO4, i.e., nickel orthophosphate represented by the formula Ni3(PO4)2, as simply as possible. In other words, two approaches, oxidation and phosphate chlorination, were investigated individually and then in combination.

[0014] More specifically, the present invention relates to a method for treating a mechanical part comprising a functional surface made of NiP, intended to come into frictional contact with another functional surface, said method comprising the step of oxidizing and / or phosphatizing said functional surface in order to artificially form an oxide layer and / or a phosphate layer respectively on said functional surface. According to the invention, the phosphate layer is a nickel phosphate layer or, as a variant, a zinc phosphate layer which can also improve tribological properties.

[0015] Several options for performing this oxidation and / or phosphatization treatment have been fully evaluated using a tribometer. - Dry oxidation using O2 plasma or using the flow of an O2 / O3 mixed gas - Generation of Ni3(PO4)2 by chemical reaction (hydrolysis) - Dry oxidation + Ni3(PO4)2 generation - Electrochemical oxidation in an aqueous medium

[0016] The presence of oxides and phosphates on the surface made of NiP stabilizes and, for example, compared to ruby, the coefficient of friction is lower than that of untreated NiP and the dry tribology is significantly improved.

[0017] The present invention also relates to a mechanical part comprising a functional surface intended to come into frictional contact with another functional surface, said NiP functional surface having been subjected to the above treatment method and comprising a layer of oxides and / or phosphates of Ni or Zn.

[0018] Another aspect of the present invention relates to a functional assembly comprising the aforementioned mechanical part and another mechanical part comprising another functional surface intended to come into frictional contact with the functional surface of said mechanical part, said functional assembly being characterized in that the frictional contact is dry.

[0019] Other objects, advantages and features of the present invention will become apparent from the following detailed description, with reference to the accompanying drawings.

Brief Description of the Drawings

[0020] [Figure 1] This is a partial diagram of a functional assembly comprising two parts, namely an escape wheel and a pallet stone, having contact surfaces treated according to the method of the present invention. [Figure 2] This is a schematic cross-sectional view of a functional component processed by the method according to the present invention. [Figure 3] This is an electron microscope image showing the distribution of two types of Ni3(PO4) crystals on the surface of the sample. [Figure 4] These are electron microscope images of two types of Ni3(PO4) crystals. [Figure 5] This figure shows the dynamic friction coefficient curves corresponding to the distance traveled for two NiP / ruby pair samples using NiP treated with the dry oxidation process according to the present invention, and for a comparison with an untreated NiP / ruby pair. [Figure 6] This figure shows the dynamic friction coefficient curves corresponding to the distance traveled for two NiP / ruby pair samples using NiP treated with the Ni3(PO4)2 generation process according to the present invention, and for a comparison with an untreated NiP / ruby pair. [Figure 7] This figure shows the dynamic friction coefficient curves corresponding to the distance traveled for two NiP / ruby pair samples using NiP treated with the dry oxidation treatment and Ni3(PO4)2 generation treatment according to the present invention, and for a NiP / ruby pair without any treatment, as a comparison. [Figure 8] This figure shows the dynamic friction coefficient curves corresponding to the distance traveled for one NiP / ruby pair sample using NiP that has undergone oxidation treatment in an aqueous medium according to the present invention, and for a comparison with an untreated NiP / ruby pair. [Modes for carrying out the invention]

[0021] The present invention relates to a mechanical part that experiences friction with another part or one or more functional surfaces of the same part at one or more of its so-called functional surfaces or contact surfaces. The mechanical part can be used in any mechanism where friction is important. These may be applications in automotive parts, electronic equipment, etc. More specifically, this may be a part used in the field of watchmaking, particularly a part of a movement. Examples of such parts include pallet stones, escape wheels, movable shafts, bearings, barrel springs, and gears. The part may be in contact with another part. For example, in the field of watchmaking, the functional assembly 1 shown in Figure 1 may include a first part 2 which is a pallet stone 4 of the anchor 5 and a second part 3 which is an escape wheel 6. More specifically, the pallet stone 4 has resting surface A and impact surface B which engage with resting surface C and impact surface D of the teeth 7 of the escape wheel 6. These surfaces A, B, C, and D are frequently used functional surfaces that experience high levels of friction and / or contact and require the use of special materials to reduce friction. Alternatively, one functional surface of a component may be in contact with another functional surface of the same component. For example, this could be a barrel spring formed from blades, where one surface of the spring is intended to be in contact with another surface of the spring.

[0022] The machine component is made of NiP at least partially. This means that at least one or more functional surfaces are made of NiP. The component may be made entirely of NiP, or it may have NiP plating on at least its functional surfaces. Other machine components, including other functional surfaces intended to come into frictional contact with the functional surfaces of the machine component, may be made of materials selected from ruby, steel, and NiP, with or without treatment according to the method of the present invention.

[0023] According to the present invention, at least the functional surface contains an oxide and / or a phosphate. Figure 2 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 chlorination treatment, and an example of oxidation and phosphate treatment is shown in Figure 2.

[0024] Oxidation can be carried out by dry oxidation or electrolysis. Dry oxidation can be achieved by heat treatment in an atmospheric pressure plasma, vacuum plasma, or an oven through which oxygen flows. For example, if the apparatus is equipped with an ozone (O3) generator, the sample can be oxidized in a vacuum reactor under oxygen plasma or through an O2 / O3 mixed gas flow. Oxidation performed artificially in this way takes the form of a highly homogeneous thin layer that is darker in color than the original substrate. It can be inferred that the resulting conversion layer is isotropic, although this has not yet been proven. Advantageously, the thickness of the oxide layer is 7–13 nm, preferably 8–12 nm. The thickness can be measured by polarization analysis using, for example, a SEMILAB SE-2000 spectroscopic ellipsometer. Advantageously, the oxide layer is a in the CIELAB color space (according to CIE No. 15, ISO 7724 / 1, DIN 5033 Teil 7, ASTM E-1164). * The value is 2.2~3, b * The value is 8 to 12, preferably 9 to 11.

[0025] Phosphating can be performed by generating phosphate on a NiP substrate. This process generates seed crystals that are advantageous for good tribological properties. Preferably, this is nickel orthophosphate (Ni3(PO4)2), which is relatively easy to generate. Zinc phosphate (Zn3(PO4)2) may also be generated.

[0026] The formation involves hydrolysis, that is, the cleavage of covalent bonds in an aqueous medium. The principle involves combining nickel in the form of nickel chloride hexahydrate (NiCl2·6H2O) with a phosphate in the form of potassium dihydrogen orthophosphate (KH2PO4). These two molecules do not react with each other when combined. On the other hand, when a hydrolyzing agent such as urea (NH2CONH2) is added and the mixture is heated to a specific temperature, usually 70-100°C, the two molecules decompose according to the following reaction chain, producing a third molecule, nickel orthophosphate. CO(NH2)2 + H2O -> 2NH3 + CO2 NiCl2->Ni ++ +2Y - Ni++ + 4NH3 -> [Ni(NH4)] 2+ 3[Ni(NH3)] 2+ + 2H2PO4 - + 8H2O -> Ni3(PO4)2·8H2O + 3NH3 + 2H2

[0027] Typically, nickel chloride hexahydrate is in an aqueous solution with a molar concentration of 0.01 - 0.06 M, potassium dihydrogen orthophosphate is in an aqueous solution with a molar concentration of 0.02 - 0.09 M, and urea is in an aqueous solution with a molar concentration of 0.01 - 0.15 M.

[0028] Nickel orthophosphate is generated on NiP. The average density of generation is 35 seed crystals per 100×100 square micrometers, which is shown in Figure 3 for this. This corresponds to 0.0035 seed crystals per square micrometer. The crystals exhibit a leaf-like appearance and form a petal-like structure. The size of the seed crystals is about 5 - 6 μm (see Figure 4) and they adhere strongly to the NiP surface.

[0029] There are alternative methods to produce nickel orthophosphate (Ni3(PO4)2). An energy source is required to cause the above hydrolysis reaction. In this case, the energy that enabled this reaction was heat. However, it is probably also possible to add this energy using cold plasma (under reduced pressure or atmospheric pressure) or ultrasonic energy.

[0030] Furthermore, there are other reactions to produce nickel orthophosphate in an aqueous or solid medium. Regarding this, the following literature can be cited. - Non-Patent Document 1 · NiSO4 and Na2HPO4 at 90°C for 1 - 5 days · NiSO4 (0.5 M) and Na3PO4 (0.5 M) at 70°C for 1 day

[0031] In these last two cases, precipitates of nickel orthophosphate are obtained.

[0032] The other two methods are described below. - Non-patent document 2 Solid-state synthesis of Ni3(PO4)2 using NiO and ammonium phosphate (NH4)2HPO4. After mixing these raw materials (into a powder), the mixture is baked in an oven without gas protection at temperatures ranging from 200 to 900°C. - Non-patent document 3 proposes NiCp2 (cyclopentadienyl nickel) and TMP (trimethyl phosphate) precursors in an O2 plasma at 300°C.

[0033] Nickel orthophosphate films may be deposited using ALD (atomic layer deposition) technology. In this case, a thin film is formed instead of a seed crystal.

[0034] Samples were prepared by oxidation and / or phosphate chlorination treatment according to the present invention, and tribological tests were performed on these samples.

[0035] The oxidation process was carried out using vacuum dry oxidation. The latter was achieved using plasma vacuum treatment. The equipment used was a "Denton Discovery PVD / PECVD" system. The sample is placed in a vacuum chamber. First, it is heated to 100-200°C. Ar gas, which has high plasma generation capacity, is introduced into the chamber, and a negative potential that can be varied in the range of 500-1000V is applied to the substrate carrier. This generates power that varies in the range of 90-380W in the Denton system used. The pressure is set to 15 μbar. Normally, this can be 10-30 μbar. The Ar plasma is ignited. As the first step, relatively heavy Ar ions are collided with it for several minutes to clean the surface. After the surface is cleaned, Ar is gradually replaced with O2 until a pure oxygen plasma is obtained. This has a yellowish tint. This oxygen plasma generates the expected oxide layer. The electron temperature of this high-energy plasma is approximately 100,000 K (100,000 Kelvin). This temperature is not a physical phenomenon, but merely represents the vibration and intense reactivity of atoms trapped within this plasma.

[0036] Approximately 10 tests were conducted under various conditions. Several parameters, such as the pressure in the vacuum chamber and the flow rates of Ar and O2, were set, while other parameters, such as the applied voltage, chamber temperature, and sample residence time in the chamber, were left variable.

[0037] Furthermore, two additional tests were conducted using the ALD Encapsulix instrument equipped with an ozone generator. This O3 gas is particularly reactive but very unstable and only lasts for a short time. This generator supplies an O2 / O3 mixed gas that can be used with or without plasma and passes through the sample in a pre-vacuumed chamber, similar to the aforementioned instrument. One test was conducted using plasma, which poses a risk of destroying O3 molecules, while the other was conducted in the form of simple chemical passage without plasma.

[0038] Ten tests were conducted using the two devices described above. The tribological results shown below were obtained for one sample from each device. One of these samples, sample number 36, was subjected to chemical flow (without plasma) of an O2 / O3 mixed gas in an ALD device for 4 hours. The other sample, sample number 8, was produced by applying 700V (172W) at 150°C for 15 minutes in a PVD device (Figure 5).

[0039] The oxidation treatment was also carried out in an aqueous medium. Oxidation was performed by simple electrolysis of water connected to the positive (+) electrode. As is well known to those skilled in the art, O2 was released. The variable parameters are as follows: - Types of solutions • Electrolytic degreasing tank (alkaline) • 1M KOH solution (alkaline) - Anodizing (acidic) in 0.1M H3PO4 medium - Immersion in alkaline, neutral, and acidic media (i.e., chemical immersion) The results of the tribology test for sample number 35 are shown below (Figure 8).

[0040] In the phosphate chlorination treatment, Ni3(PO4)2 was generated according to the following procedure. - Nickel source: Nickel chloride hexahydrate (NiCl2·6H2O) dissolved at a rate of 1,570 mg per 200 cc of water, i.e., a 0.033 M solution. - Phosphate source: Potassium dihydrogen orthophosphate (KH2PO4) dissolved in water at a ratio of 1,794 mg per 200 cc, i.e., a 0.066 M solution. - Hydrolyzate source: Urea (NH2CONH2) is dissolved in the following different proportions. • 300 mg per 200 cc of water (0.025 M solution) • 600 mg per 200 cc of water (0.05 M solution) • 900 mg per 200 cc of water (0.075 M solution) • 1,200 mg per 200 cc of water (0.1 M solution)

[0041] These four concentrations affect the sheet dimensions (length, width, and thickness) during seed crystal formation. Next, 1 cc of surfactant (sodium lauryl sulfonate) is added. The sample is pre-washed and 5 A / dm 2 The sample is activated by cathode electrolytic degreasing. Then, it is vertically immersed in a hydrolysis solution. The sample is heated to 90°C, and once the solution reaches that temperature, it is held for 45 minutes. After this time has elapsed, the sample is removed, rinsed, and dried.

[0042] The fixed parameters are as follows: - Reagent concentrations (NiCl 20.033M and KH2PO 40.066M) - Hydrolysis temperature (90℃) The variable parameters are as follows: - Concentration of hydrolyzing agent - Plate holding time in the beaker - pH of the solution Furthermore, to increase the number of locations where the growth occurs, several samples are polished with a polishing disc (P4000 or 5μm).

[0043] Twenty-four samples were processed. The tribological results for sample number 15, which was processed for 45 minutes at a maximum urea concentration of 0.1 M and pH 4.08, and sample number 14, which was processed for 30 minutes under the same conditions, are shown below (Figure 6).

[0044] Furthermore, samples were prepared by combining two treatments: first, preferential oxidation treatment, followed by phosphate chlorination treatment. Some samples were subjected to the dry oxidation treatment described in Sample 8 above, and then generated using 750 mg of hydrolyzing agent (urea). It should be noted that, in order to preserve the surface that had been previously plasma-oxidized, electrolytic degreasing before generation should be performed using anodic degreasing rather than cathodic degreasing.

[0045] The tribology test was performed on a 2 mm diameter ruby ​​sphere using an alternating linear mode. The test conditions were as follows: - Normal load: 1mN - Maximum sine wave speed: 10mm / s - Amplitude: 4mm - Travel distance: 25m - Condition: Dry

[0046] When a reference sample consisting of a rough-surfaced NiP disc manufactured using the LIGA (Lithography, Electroforming, Molding) method was tested, the tribological results showed a significant change in the coefficient of friction. - Starting: Over 0.5 - Wrapping stage: 0.5 - Decreases to 0.25 - With numerous peaks, it stabilizes at 0.25.

[0047] All tests were conducted using the same configuration and compared to this reference sample.

[0048] Figure 5 shows that dry oxidation not only stabilizes the coefficient of friction but also suppresses the lapping stage of NiP. Oxidation using O2 / O3 flow shows a significant advantage in terms of improving the coefficient of friction (Sample 36).

[0049] As shown in Figure 6, the generation of Ni3(PO4)2 suppresses the peak of the friction coefficient, reducing it to 0.15 in the dry process. The decrease in the friction coefficient at the start is very rapid, which suppresses the lapping phase.

[0050] In oxidation in an aqueous medium, as shown in Figure 8, the lapping stage is extremely short, the coefficient of friction decreases to 0.15 in the dry state, and stabilization occurs.

[0051] The sample combining the two treatments (Figure 7) shows stabilization, with the coefficient of friction decreasing to 0.15 in the dry process. Depending on the degree of occurrence, the most significant effect is seen during the lapping stage, which is somewhat longer, but the initial coefficient of friction is significantly lower than that of the reference sample.

[0052] Colorimetric measurements were also performed on samples oxidized by ALD, and on comparison samples that underwent natural oxidation, which can take several years, without accelerated oxidation treatment. Colorimetric measurement value L of polished sample. * a * b * The measurements were taken using a Konica Minolta CM-3610A spectrophotometer under the following conditions: SCI (including specular reflection) and SCE (excluding specular reflection), tilt of 8°, and SAV measurement diameter of 4 mm. The results are shown in the table below.

[0053] [Table 1]

[0054] TIFF2026520168000003.tif31170

[0055] TIFF2026520168000004.tif6170

[0056] As a result, Delta E is 5.4. This leads to the conclusion that the treated sample is darker in color than the reference sample. In other words, an oxide layer was formed on the surface of the sample. This oxide layer was rigorously characterized by polarization analysis. The layer thickness is estimated to be 9-10 nm. On the other hand, its refractive index of 1.8-2 does not match that of NiO (2.1818), indicating that the composition of this layer is mainly phosphorus oxide rather than NiO, although trace amounts of NiO may be present. The refractive indices of phosphorus trioxide (P2O3), phosphorus tetroxide (P2O4), and phosphorus pentoxide (P2O5) are approximately 1.82, which is within the identified range. This is a logical result because the reaction rate of NiO is slower than that of phosphate, and phosphate is dominant and forms more easily and quickly than NiO.

[0057] In conclusion, the presence of oxides and phosphates on a NiP surface offers significant advantages in dry tribology.

Claims

1. A functional assembly (1) comprising a first mechanical component (2, 3) having a first functional surface (8) made of NiP, and a second mechanical component having a second functional surface intended to frictionally contact the first functional NiP surface (8) of the first mechanical component (2, 3), wherein the first functional NiP surface each comprises an oxide layer (9) and / or a phosphate layer (10), the phosphate layer (10) being a layer of nickel phosphate or zinc phosphate, and the frictional contact between the first mechanical component and the second mechanical component is dry.

2. The functional assembly (1) according to claim 1, 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 claim 2, characterized in that the second functional NiP surface each comprises an oxide layer (9) and / or a phosphate layer (10), and the phosphate layer (10) is a layer of nickel phosphate or zinc phosphate.

4. The functional assembly according to claim 3, characterized in that the nickel phosphate or zinc phosphate layer (10) contains seed crystals.

5. The aforementioned seed crystal is Ni ３ (PO ４ ) ２ The functional assembly according to claim 4, characterized in that it is a seed crystal.

6. The functional assembly according to any one of claims 1 to 5, characterized in that the oxide layer (9) has a thickness of 7 to 13 nm, preferably 8 to 12 nm.

7. The functional assembly according to claim 6, characterized in that the oxide layer (8) mainly contains phosphorus oxide.

8. The oxide layer (9) is L ＊ a ＊ , b ＊ In the color space, a is 2.2 to 3. ＊ The value is 8 to 12, preferably 9 to 11. ＊ A functional assembly according to any one of claims 1 to 7, characterized by having a value.

9. A functional assembly according to any one of claims 1 to 8, characterized in that it is a component of a watch movement.

10. The functional assembly according to any one of claims 1 to 9, characterized in that it comprises mechanical parts (2, 3) selected from a pallet stone (4), an escape wheel (6), a movable shaft, a bearing, a barrel spring, and a gear.

11. A method for processing mechanical parts (2, 3) of a functional assembly according to any one of claims 1 to 10, comprising the step of oxidizing or phosphate-chlorinating the functional surface (8) in order to artificially form an oxide layer (9) and / or a phosphate layer (10) on the functional surface (8), wherein the phosphate layer (10) is a layer of nickel phosphate or zinc phosphate.

12. The oxidation step is carried out by dry oxidation by atmospheric pressure plasma, vacuum plasma, through-flow of an O ２ / O ３ mixed gas with or without plasma, or heat treatment in an oven through which oxygen is passed, or by oxidation by electrolysis in an aqueous medium, and is characterized in that it is the treatment method according to claim 11. ２ / O ３ ​

13. The treatment method according to claim 11 or 12, characterized in that the phosphate chlorination step is carried out by ALD deposition to form a phosphate film or by a chemical reaction to form a phosphate seed crystal.

14. A processing method according to any one of claims 11 to 13, characterized in that it includes a phosphate chlorination step following an oxidation step.

15. The oxidation process is a sub-process of the following: - Heat the mechanical parts (2, 3) to 100-200°C and place the mechanical parts (2, 3) into a substrate carrier in a vacuum chamber. - Introducing Ar gas into the vacuum chamber and applying a negative potential of 500 to 1000 V to the substrate carrier. The treatment method according to any one of claims 11 to 14, characterized by being a dry oxidation accompanied by a dry oxidation.

16. The phosphate chlorination step involves nickel chloride hexahydrate (NiCl ２ 6H ２ O), potassium dihydrogen orthophosphate (KH ２ PO ４ ), and urea (NH ２ CONH ２ The processing method according to any one of claims 11 to 15, characterized in that it is carried out by a chemical reaction between ).

17. The treatment 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 orthophosphate 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.

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