CN114351086B - Preparation method of PVD (physical vapor deposition) coating on outer circle and end face of piston ring - Google Patents
Preparation method of PVD (physical vapor deposition) coating on outer circle and end face of piston ring Download PDFInfo
- Publication number
- CN114351086B CN114351086B CN202210011671.2A CN202210011671A CN114351086B CN 114351086 B CN114351086 B CN 114351086B CN 202210011671 A CN202210011671 A CN 202210011671A CN 114351086 B CN114351086 B CN 114351086B
- Authority
- CN
- China
- Prior art keywords
- piston ring
- coating
- face
- pvd
- outer circle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000576 coating method Methods 0.000 title claims abstract description 61
- 239000011248 coating agent Substances 0.000 title claims abstract description 59
- 238000002360 preparation method Methods 0.000 title claims abstract description 8
- 238000005240 physical vapour deposition Methods 0.000 title abstract description 35
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 24
- 238000000034 method Methods 0.000 claims abstract description 17
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 11
- 238000005530 etching Methods 0.000 claims abstract description 5
- 238000004140 cleaning Methods 0.000 claims abstract description 4
- 229910052751 metal Inorganic materials 0.000 claims description 20
- 239000002184 metal Substances 0.000 claims description 20
- 150000004767 nitrides Chemical class 0.000 claims description 16
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 12
- 230000037452 priming Effects 0.000 claims description 12
- 239000007789 gas Substances 0.000 claims description 10
- 229910052786 argon Inorganic materials 0.000 claims description 6
- 238000000151 deposition Methods 0.000 claims description 6
- 230000008021 deposition Effects 0.000 claims description 5
- 238000005237 degreasing agent Methods 0.000 claims description 4
- 239000013527 degreasing agent Substances 0.000 claims description 4
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims description 2
- 238000007747 plating Methods 0.000 abstract description 20
- 239000011651 chromium Substances 0.000 abstract description 15
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 abstract description 9
- 229910052804 chromium Inorganic materials 0.000 abstract description 9
- 238000005260 corrosion Methods 0.000 abstract description 5
- 230000007797 corrosion Effects 0.000 abstract description 5
- 238000002425 crystallisation Methods 0.000 abstract description 3
- 230000008025 crystallization Effects 0.000 abstract description 3
- 230000007613 environmental effect Effects 0.000 abstract description 2
- 238000000227 grinding Methods 0.000 abstract description 2
- 238000011068 loading method Methods 0.000 abstract description 2
- 238000003754 machining Methods 0.000 abstract description 2
- 238000007789 sealing Methods 0.000 abstract description 2
- 238000009713 electroplating Methods 0.000 abstract 1
- 238000005498 polishing Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 5
- 238000005121 nitriding Methods 0.000 description 4
- 238000005299 abrasion Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000005238 degreasing Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000002551 biofuel Substances 0.000 description 1
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 238000007733 ion plating Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Pistons, Piston Rings, And Cylinders (AREA)
Abstract
The invention discloses a preparation method of a PVD coating on the excircle and end face of a piston ring, which comprises the following steps: cleaning the plated surface of the piston ring; loading the plated end face of the piston ring outwards into a clamp and placing the clamp in PVD equipment at intervals; etching the plated surface of the piston ring; and introducing nitrogen to deposit the coating, wherein the bias voltage is 20-25V, and the cathode current is 80-100A when the coating is deposited. According to the invention, the outer circle and the end face are simultaneously PVD-plated, the outer corner plating is better in combination, the quality is more stable, the end face of the piston ring is PVD-resistant, high-temperature-resistant, corrosion-resistant and seizure-resistant, the process flow is less, the physical vapor deposition method is adopted to replace the electroplating chromium, and the environmental protection performance is good; the plating layer is fine and smooth in crystallization, expensive grinding machining which is necessary in the traditional process can be eliminated, the end face of the PVD is micro-polished, the roughness is good, and initial running-in and end face sealing are facilitated; the piston ring and the PVD clamp are convenient and quick to assemble and disassemble, and the piston ring is simple to operate and suitable for industrialization.
Description
Technical Field
The invention relates to surface treatment of a piston ring, in particular to a preparation method of PVD (physical vapor deposition) coating on the outer circle and the end face of the piston ring.
Background
The automobile engine is forward developed in the directions of high explosion pressure, high EGR, low fuel consumption, low exhaust emission and the like, and particularly, a great amount of corrosive gas and water vapor are arranged in a cylinder sleeve in the working process of a gas engine and a biofuel engine, and the abrasion resistance, corrosion resistance and high temperature resistance of a piston ring are particularly important for the overall fuel consumption, power output and emission of the engine.
Currently, the outer circle treatment modes of the piston ring include chromium plating, PVD, nitriding and DLC (diamond-like carbon); the strengthening of the end face of the piston ring mainly comprises chromium plating, nitriding and DLC, and the defects are that: the existing hexavalent chromium hard chromium plating process has large pollution and higher treatment cost, and is a process which is eliminated gradually; the chromium plating has the advantages that the roughness of the side surface of the piston ring is increased due to coarse crystallization, the service temperature of the existing chromium plating layer is low, the hardness of the plating layer is greatly reduced below 280 ℃, the corrosion resistance of the nitriding layer is poor, the DLC (diamond like carbon) hardness is high, the friction coefficient is ultralow, the wear resistance is good, but the problems of high-temperature stability of the plating layer, brittleness of the plating layer and the like cannot be thoroughly solved, and the production cost is high.
Disclosure of Invention
The invention aims to: the invention aims to provide a preparation method of a PVD coating on the outer circle and the end face of a piston ring, which solves the problem that the method is not suitable for a surface treatment method with no pollution, good high-temperature stability, wear resistance and corrosion resistance on the outer circle and the end face.
The technical scheme is as follows: the invention relates to a preparation method of a PVD coating on the excircle and the end face of a piston ring, which comprises the following steps:
(1) Cleaning the plated surface of the piston ring;
(2) Loading the plated end face of the piston ring outwards into a clamp and placing the clamp in PVD equipment at intervals;
(3) Etching the plated surface of the piston ring;
(4) Introducing argon to deposit a single metal priming coating;
(5) And nitrogen is introduced to deposit a single metal nitride or multi-metal nitride coating.
Preferably, in the step (1), the cleaning is performed by using ultrasonic waves and a degreasing agent.
In order to deposit metal ions on the end faces of the piston rings, the piston rings are separated one by a gasket in the step (2).
In order to increase the binding force between the coating and the piston ring, the single metal priming coating deposited in the step (4) is Cr priming coating, the thickness of the outer circle of the Cr priming coating is 2-4 mu m, and the thickness of the end face is 1-3 mu m. When a single metal priming coating is deposited in the step (4), the vacuum degree is 0.5-1.0E-2 mbar, ar gas flow is 400-600sccm, the temperature is 400-430 ℃, the bias voltage is 20-25V, and the cathode arc current is 80-100A.
In order to ensure the quality of the plating layer on the end face of the piston ring and prevent the influence on the outer diameter shrinkage dimension of the piston ring, the single metal nitride plating layer in the step (5) is CrN, and the multi-element metal nitride plating layer is Cr (Me) N; wherein Me is one or a combination of at least two of Al, mo, B or Ti, the thickness of a CrN or Cr (Me) N plating layer is 13-41 mu m, and the thickness of an end face is 4-27 mu m. When a single metal nitride or multi-metal nitride coating is deposited in the step (5), the temperature is 460-480 ℃, the vacuum degree is 2.5-3.5E-2 mbar, the Ar gas flow is 40-60sccm, the nitrogen gas flow is 760-840 sccm, the bias voltage is 28-32V, and the cathode arc current is 92-120A.
And (3) preventing the ring body with overhigh temperature from oxidizing or splashing, facilitating the subsequent polishing process, ending after depositing for 5-8 hours, cooling to below 120 ℃ under the condition of the nitrogen flow of 600-800 sccm, opening a vacuum cavity to take out a piston ring, and polishing the surface of the coating.
The beneficial effects are that: according to the invention, a physical vapor deposition method of vacuum multi-arc ion plating is adopted, a plurality of multi-arc ion sources are used for discharging to simultaneously deposit PVD (physical vapor deposition) coatings on the outer circle and the end face of the piston ring, the outer corner coatings are better in combination, the quality is more stable, the end face of the piston ring is PVD-resistant, wear-resistant, high-temperature-resistant and corrosion-resistant, the seizure resistance is good, the process flow is less, the production period is short, the production cost is low, and the physical vapor deposition method is adopted to replace chromium plating, so that the environmental protection performance is good; the plating layer is fine and smooth in crystallization, expensive grinding machining which is necessary in the traditional process can be eliminated, the end face of the PVD is micro-polished, the roughness is good, and initial running-in and end face sealing are facilitated; the piston ring and the PVD clamp are convenient and quick to assemble and disassemble, and the piston ring is simple to operate and suitable for industrialization.
Drawings
FIG. 1 is a schematic view of the structure of PVD coating of the outer circle and end face of the present invention;
FIG. 2 is a schematic diagram of a piston ring tooling of the present invention;
FIG. 3 is a graph showing the abrasion loss in example 1;
FIG. 4 is a mechanical load diagram of example 1;
FIG. 5 is a thermal load diagram of example 1;
FIG. 6 is a graph showing the abrasion loss in example 2;
FIG. 7 is a mechanical load diagram of example 2;
FIG. 8 is a thermal load diagram of example 2.
Detailed Description
The invention will be further described with reference to the drawings and examples.
As shown in figures 1-2, the tooling of the PVD fixture for simultaneously positioning the outer circle and the end face of the piston ring comprises a positioning plate, a gasket, a central rod and a pressing plate, wherein the positioning plate is arranged on the central rod, the piston ring is arranged on the positioning plate, the positioning plates are separated by the gasket, and the central rod is arranged on a rotating frame to ensure that the distance between the piston ring and a target is the same. The excircle and the end face PVD coating 2 are deposited on a matrix, the matrix is a cast iron/cast steel/alloy steel/stainless steel/nitriding piston ring matrix, the thickness of the excircle PVD coating is 0.015-0.045 mm, the thickness of the end face PVD coating is 0.005-0.03 mm, and the end face coating can be a single end face or a double end face.
Example 1
The invention discloses a preparation method of a PVD coating on the excircle and the end face of a piston ring, which comprises the following steps:
(1) And (3) fine washing: the ultrasonic current 2A is adopted, and the commercial degreasing agent is 10g/l; degreasing time is 6 minutes;
(2) Clamping: placing the cleaned piston rings into a special fixture, placing the piston rings into positioning sheets, separating the piston rings one by using gaskets, and enabling the plated surfaces of the end faces to face outwards;
(3) Etching: the temperature is 360-400 ℃, the vacuum degree is 1.0-2.0E-3 mbar, the argon flow is 50sccm, the bias voltage is 800-900V, the cathode current is 80-90A, and the time is 45min;
(4) Introducing argon to deposit Cr priming coating, controlling vacuum degree at 0.5-1.0E-2 mbar, ar gas flow rate at 500sccm, coating temperature at 410-430 ℃, bias voltage at 20-25V, cathode arc current at 80-100A, and deposition time at 45min.
(5) Introducing nitrogen to deposit CrN or multi-element nitride coating, controlling vacuum degree at 2.5-3.5E-2 mbar, ar gas flow rate at 50sccm, nitrogen flow rate at 750sccm, coating temperature at 460-480 ℃, bias voltage at 28-32V, cathode arc current at 92-120A, and deposition time at 5h.
(6) Cooling: introducing 600-800 sccm nitrogen, quenching to below 120 ℃, and opening the furnace door to discharge;
(7) And (5) clamping unloading and checking: removing the piston ring from the positioning sheet;
(8) Micro polishing: and polishing the outer circle and the end face of the piston ring on a 3M polishing wheel for 2 times.
After polishing the piston ring the PVD coating of the piston ring is detected, thickness of outer circle plating: 0.02-0.025 mm; the thickness of the end face plating layer is the total thickness of the metal transition layer and the nitride layer: 0.01-0.012 mm; coating hardness: 1756HV; coating binding force: good. Coating roughness RZ1.3.
The friction and wear test is carried out on the piston ring after coating, the test result is shown in figure 3, and the figure 3 shows that the PVD coating wear amount of the piston ring is reduced by more than 40% compared with that of electroplated chromium.
The PVD coating was tested to have not only good wear resistance, but also good mechanical load resistance as shown in fig. 4 and thermal load capacity as shown in fig. 5.
Example 2
(1) And (3) fine washing: the ultrasonic current 2A is adopted, and the commercial degreasing agent is 10g/l; degreasing time is 6 minutes;
(2) Clamping: placing the cleaned piston rings into a special fixture, placing the piston rings into positioning sheets, and separating the piston rings one by using gaskets; the plated surface of the end face faces outwards;
(3) Etching: the temperature is 300-350 ℃, the vacuum degree is 1.0-2.0E-3 mbar, the argon flow is 50sccm, the bias voltage is 900-950V, the cathode current is 80-90A, and the time is 35min;
(4) Introducing argon to deposit Cr priming coating, controlling vacuum degree at 0.5-1.0E-2 mbar, ar gas flow rate at 600sccm, coating temperature at 410-430 ℃, bias voltage at 20-25V, cathode arc current at 80-100A, and deposition time at 60min.
(5) Introducing nitrogen to deposit CrN or multi-element nitride coating, controlling the vacuum degree at 2.5-3.5E-2 mbar, ar gas flow rate at 60sccm, nitrogen flow rate at 800sccm, coating temperature at 460-480 ℃, bias voltage at 28-32V, cathode arc current at 92-120A, and deposition time at 7h;
(6) Cooling: introducing 600-800 sccm nitrogen, quenching to below 100 ℃, and opening the furnace door to discharge;
(7) And (5) clamping unloading and checking: removing the piston ring from the positioning sheet;
(8) Micro polishing: and polishing the outer circle and the end face of the piston ring on a 3M polishing wheel for 2 times.
After polishing the piston ring the PVD coating of the piston ring is detected, thickness of outer circle plating: 0.03-0.035 mm; the thickness of the end face plating layer is the total thickness of the metal transition layer and the nitride layer: 0.015-0.020 mm; coating hardness: 1690HV; coating binding force: good. Coating roughness RZ1.6.
The friction and wear test is carried out on the piston ring after coating, the test result is shown in figure 6, and the figure 6 shows that the PVD coating wear amount of the piston ring is reduced by more than 40% compared with that of electroplated chromium.
The PVD coating was tested to have not only good wear resistance, but also good mechanical load resistance as shown in fig. 7 and thermal load capacity as shown in fig. 8.
Claims (5)
1. The preparation method of the PVD coating on the outer circle and the end face of the piston ring is characterized by comprising the following steps:
(1) Cleaning the plated surface of the piston ring;
(2) The method comprises the steps that a plated end face of a piston ring is outwards arranged in a clamp and is arranged in PVD equipment at intervals, the clamp comprises a locating plate, a gasket, a central rod and a pressing plate, the locating plate is arranged on the central rod, the piston ring is arranged on the locating plate, the locating plates are separated by the gasket, the central rod is arranged on a rotating frame of the PVD equipment, and the distance between the piston ring and a target is guaranteed to be the same;
(3) Etching the plated surface of the piston ring;
(4) Argon is introduced to deposit a single metal priming coating, the single metal priming coating is a Cr priming coating, the thickness of the outer circle of the Cr priming coating is 2-4 mu m, and the thickness of the end face is 1-3 mu m;
(5) Nitrogen is introduced to deposit a single metal nitride or multi-metal nitride coating, wherein the single metal nitride coating is CrN, and the multi-metal nitride coating is Cr (Me) N; wherein Me is one or a combination of at least two of Al, mo, B or Ti, the outer circle thickness of CrN or Cr (Me) N is 13-41 mu m, and the end face thickness is 4-27 mu m.
2. The method for preparing the PVD coating of the outer circle and the end face of the piston ring according to claim 1, wherein the step (1) is performed by ultrasonic wave and degreasing agent.
3. The method for preparing the PVD coating on the outer circle and the end face of the piston ring according to claim 1, wherein when the single metal priming coating is deposited in the step (4), the vacuum degree is 0.5-1.0E-2 mbar, ar gas flow is 400-600sccm, the temperature is 400-430 ℃, the bias voltage is 20-25V, and the cathode arc current is 80-100A.
4. The method for preparing the PVD coating on the outer circle and the end face of the piston ring according to claim 1, wherein the temperature is 460-480 ℃, the vacuum degree is 2.5-3.5E-2 mbar, the Ar gas flow is 40-60sccm, the nitrogen gas flow is 760-840 sccm, the bias voltage is 28-32V, and the cathode arc current is 92-120A when the single metal nitride or the multi-metal nitride coating is deposited in the step (5).
5. The method for preparing PVD coating on outer circle and end face of piston ring according to any one of claims 1-4, wherein the deposition is finished for 5-8 hours, and the piston ring is cooled to below 120 ℃ under the flow rate of nitrogen of 600-800 sccm and discharged from the furnace.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210011671.2A CN114351086B (en) | 2022-01-06 | 2022-01-06 | Preparation method of PVD (physical vapor deposition) coating on outer circle and end face of piston ring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210011671.2A CN114351086B (en) | 2022-01-06 | 2022-01-06 | Preparation method of PVD (physical vapor deposition) coating on outer circle and end face of piston ring |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114351086A CN114351086A (en) | 2022-04-15 |
| CN114351086B true CN114351086B (en) | 2024-08-09 |
Family
ID=81107280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210011671.2A Active CN114351086B (en) | 2022-01-06 | 2022-01-06 | Preparation method of PVD (physical vapor deposition) coating on outer circle and end face of piston ring |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114351086B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103789725A (en) * | 2014-01-29 | 2014-05-14 | 仪征亚新科双环活塞环有限公司 | Multilayer multi-component compound hard PVD (Physical Vapor Deposition) plating layer on surface of piston ring, piston ring and preparation process |
-
2022
- 2022-01-06 CN CN202210011671.2A patent/CN114351086B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103789725A (en) * | 2014-01-29 | 2014-05-14 | 仪征亚新科双环活塞环有限公司 | Multilayer multi-component compound hard PVD (Physical Vapor Deposition) plating layer on surface of piston ring, piston ring and preparation process |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114351086A (en) | 2022-04-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3221892B2 (en) | Piston ring and its manufacturing method | |
| CN111270203B (en) | AlCrNbSiTiCN high-entropy alloy nano composite coating for die-casting die and preparation method thereof | |
| EP2907889B1 (en) | A multilayer multi-element composite hard PVD coating on the surface of a piston ring, a piston ring and a preparation process | |
| CN101430004B (en) | A kind of PVD chromium-based ceramic composite coating piston ring and preparation method thereof | |
| CN108728793B (en) | A kind of tough and corrosion-resistant CrAlN/Cr2AlC multilayer film coating and preparation method thereof | |
| CN102825855B (en) | Ultra-thick CrSiBN composite coating on surface of base body and preparation method thereof | |
| CN101665940A (en) | Method for preparing diamond-like composite coating on surface of piston ring | |
| CN107130212A (en) | A kind of thick tantalum coating of high hard wear-resisting heat shock resistance and preparation method thereof | |
| JP2771947B2 (en) | Sliding member | |
| CN110863182A (en) | Method for strengthening surface coating of gear cold extrusion die | |
| US11377729B2 (en) | Post-processing method for improving anti-wear and friction-reducing properties of CrN coating | |
| JP2739722B2 (en) | piston ring | |
| CN114351086B (en) | Preparation method of PVD (physical vapor deposition) coating on outer circle and end face of piston ring | |
| JPH08312779A (en) | Slide material and piston ring | |
| CN114196918A (en) | Power station high-temperature bolt protective coating and preparation method thereof | |
| CN110079777A (en) | Method for preparing Cr coating on round head surface of ball valve | |
| KR101551963B1 (en) | Coating material for aluminum die casting and method for coating the same | |
| JP2007132423A (en) | piston ring | |
| CN116555716A (en) | Stainless steel composite material and preparation method thereof | |
| CN117987773B (en) | Wear-resistant low-friction coating piston ring and preparation method thereof | |
| CN113913736A (en) | A kind of corrosion-resistant and wear-resistant Cr-PVD composite coating and preparation method thereof | |
| CN215370059U (en) | High-wear-resistance piston ring | |
| CN110923639B (en) | MoTiCrWN composite coating attached to surface of piston ring, piston ring and preparation method of MoTiCrWN composite coating | |
| CN116162902B (en) | A composite and a method for preparing the same | |
| CN118256882A (en) | Wear-resistant corrosion-resistant double-effect protective hard film and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |