CN111663110A

CN111663110A - Molybdenum disulfide/yttrium stabilized zirconia composite film with high wear resistance and anti-irradiation performance and preparation method thereof

Info

Publication number: CN111663110A
Application number: CN202010719235.1A
Authority: CN
Inventors: 王鹏; 程勇; 段泽文; 赵晓宇
Original assignee: Lanzhou Institute of Chemical Physics LICP of CAS; Hefei Institutes of Physical Science of CAS
Current assignee: Lanzhou Institute of Chemical Physics LICP of CAS; Hefei Institutes of Physical Science of CAS
Priority date: 2020-07-23
Filing date: 2020-07-23
Publication date: 2020-09-15
Anticipated expiration: 2040-07-23
Also published as: CN111663110B

Abstract

The invention discloses a molybdenum disulfide/yttrium stabilized zirconia composite film (MoS) with high wear resistance and irradiation resistance₂YSZ) is prepared by preparing MoS by radio frequency magnetron sputtering physical vapor deposition₂The film is thermally annealed to eliminate MoS₂Intrinsic defects of the crystal in the magnetron sputtering growth process; the resulting film MoS₂(002) Preferred orientation, good crystallization property, low friction and high wear resistance (average friction coefficient)<0.05Wear life>2×10⁵Rotary) and high wear-resistant and anti-radiation characteristics, thereby realizing MoS₂The low friction and radiation-resistant self-adaptive integration of the/YSZ-based composite film can be used for lubricating mechanical moving parts in the irradiation environment of a reactor and a fusion reactor.

Description

Molybdenum disulfide/yttrium stabilized zirconia composite film with high wear resistance and anti-irradiation performance and preparation method thereof

Technical Field

The invention relates to a molybdenum disulfide/yttrium stabilized zirconia composite film (MoS) with high wear resistance and anti-irradiation performance₂YSZ) and a preparation method thereof, which are mainly used for lubricating mechanical moving parts in a reactor and a fusion reactor irradiation environment.

Background

The energy is the basis of the development of human society, and nuclear energy becomes an important resource which can be developed and used on a large scale and is clean, safe and efficient at present. Chinese nuclear power development is divided into three steps: advanced pressurized water reactors, fast reactors/breeder reactors, fusion reactors. Most of the work at present mainly focuses on the mechanism research of radiation damage resistance of the nuclear structure material of the reactor. Up to now, the radiation damage dose of the designed reactor nuclear structure material is close to 200 dpa. Fourth generation reactor and fusion reactor engineering designs have entered into the demonstration phase of construction applications, where the nuclear reactor key mechanical motion mechanisms, such as the service environment and requirements of the EAST plant telemanipulator arm, are increasingly demanding, complex, and variable: environmental alternation 10^-5-10⁵Pa, neutron flux 10¹²-10¹⁵High contact stress of 1.5GPa, stroke error less than 0.1%, etc. The irradiation environment of the reactor requires that the lubricating material applied to the mechanical moving part has higher irradiation resistance. However, there are few reports on the damage behavior of solid lubricating materials under irradiation environment and the correlation mechanism between the accumulation effect and the tribological performance of the thin film. Therefore, the design of the solid lubricating film material with low friction, high wear resistance and high radiation resistance has epoch-making significance for the design of advanced nuclear energy and the breakthrough of the technical bottleneck restricting the safety reliability and the service life of equipment.

At present, metal sulfides are an important material among many solid lubricants, such as WS₂，MoS₂，FeS，NbS₂And the like. Wherein MoS₂Has been developed as the most widespread solid lubricant because of its excellent lubricating properties and low preparation cost. Calculation shows that the nano-structure MoS₂Maximum atom of (2)The off-digit rate can reach 1.51 × 10^-8dpa/s, discloses MoS₂Has certain radiation resistance. In the field of friction, in order to increase the hardness, density, carrying capacity and wear life of films, the MoS technique₂The doping of metal, non-metal elements, oxides and the like has been developed into an effective method. However, most of the elements are doped at the sacrifice of MoS₂Degree of order, increase of MoS₂The unsaturation of the crystal and the introduction of voids, among other defects. The existence of the defects can greatly reduce the dislocation threshold of S, Mo atoms and reduce MoS₂The intrinsic anti-irradiation capability of the crystal further promotes the generation of collision cascade in the irradiation process to cause MoS₂Eventually leading to rapid lubrication failure. Therefore, there is an urgent need to develop new technologies and methods to enhance MoS₂MoS in base film₂The intrinsic radiation resistance of the crystal enables the crystal to show excellent lubricating property under the irradiation environment.

Disclosure of Invention

The invention aims to provide a MoS with high wear resistance and radiation resistance₂A preparation method of/YSZ composite film.

One, MoS₂Preparation of/YSZ composite film

MoS of the invention₂The preparation method of the/YSZ composite film is to firstly adopt the radio frequency magnetron sputtering physical vapor deposition technology to prepare MoS₂The film is thermally annealed to eliminate MoS₂Intrinsic defects of the crystal in the magnetron sputtering growth process; the obtained film has good crystallization property and MoS₂Exhibits preferred (002) orientation, low friction coefficient and excellent wear resistance.

And the substrate cleaning is to place the substrate material in anhydrous acetone and alcohol for cleaning for 15-20 min in sequence and blow-drying.

The radio frequency magnetron sputtering physical vapor deposition technology is used for preparing MoS₂the/YSZ composite film process comprises placing cleaned substrate material on the chassis of multi-target magnetron sputtering equipment, and vacuum pumping to 1.3 × 10^-3Pa, introducing argon, and carrying out Ar under the condition that the substrate is biased to 400V⁺Ion(s)Cleaning to remove oxide on the surface of the substrate; firstly, depositing a Ti transition layer with the thickness of 100-300 nm by using direct current sputtering; co-sputtering MoS under the condition of no substrate bias voltage₂Coating with YSZ target for 90-120 min to obtain MoS₂a/YSZ film; then MoS₂the/YSZ film is placed in annealing equipment for thermal annealing treatment.

Ar⁺In the ion cleaning, the substrate temperature is controlled at 100-150 ℃, the argon flow is controlled at 40sccm, and the air pressure is adjusted to 7.5 Pa.

In the direct current sputtering deposition of the Ti transition layer, the substrate bias voltage is removed, the working air pressure is 0.65Pa, and the working current of the Ti target is controlled at 0.5A.

Co-sputtering MoS₂In coating with YSZ target, MoS₂Selecting MoS with the purity of 99.9% as the target material₂ZrO in YSZ target₂:Y₂O₃5at% of 95: 60-80 mm of target base distance. The argon flow rate was controlled at 40sccm and the working gas pressure was maintained at 0.65 Pa. MoS₂The target deposition power is kept at 250W, the YSZ target deposition power is kept at 150W, the film deposition time is controlled to be 1.5-2 h, and the obtained MoS₂The thickness of the/YSZ film is 4-6 um.

During the annealing process, the vacuum is finally pumped to 6.7 × 10^-7mbar, heating to 600 ℃ in 57 minutes, and keeping the temperature for 1 minute; and after the annealing is finished, cooling to room temperature to obtain the molybdenum disulfide/yttrium stabilized zirconia composite film.

Two, MoS₂Structure and performance of/YSZ composite film

1. Radiation resistance

To test MoS₂The anti-irradiation characteristic of the/YSZ composite film is that heavy ions (Au) are respectively carried out on the film before and after annealing under three flows²⁺) Irradiation experiment of (3.3 × 10)¹⁴、6.6×10¹⁴And 1.65 × 10¹⁵ion/cm². FIG. 1 shows MoS₂XRD spectrum of YSZ film, wherein (a) XRD spectrum changes after non-annealed film irradiation and (b) XRD spectrum changes after annealed film irradiation, X-ray diffraction experiment shows that when irradiation dose is increased to 1.65 × 10¹⁵Au²⁺/cm²The annealed composite film still appeared very goodStrong (002) orientation preferential peak, which shows that the composite film has extremely strong heavy ion irradiation resistance.

FIG. 2 shows MoS₂The analysis result of the X-ray photoelectron spectrum of the/YSZ composite film shows that the composite film MoS which is not annealed₂The content of the composite film MoS is obviously lower than that of the composite film MoS subjected to annealing treatment₂And the content indicates that the composite film without annealing treatment has a large number of defects such as vacancies.

FIG. 3 shows MoS₂HRTEM image of/YSZ composite film cross section. Wherein (a) a topographic map of the unannealed film after irradiation; (b) and (5) a topographic map after the annealing film is irradiated. HRTEM shows that after heavy ion irradiation, the original deposition film has a layered structure, MoS, inside the film₂The crystals were severely damaged and exhibited amorphization characteristics. After the film after annealing treatment is irradiated by heavy ions, MoS with the grain size of 7-15nm₂Completely arranged in the irradiated area and still maintains good crystallinity. The heat treated film has a greatly reduced MoS as compared to the untreated film₂Sensitivity of the crystal to irradiation by heavy ions. Therefore, the film has stronger radiation damage resistance in structure.

2. Frictional properties

GCr15 is used as a dual, the rotating speed is 1000r/min, the rotating radius is 3 mm, and the load is 3N under the vacuum environment, so that the friction performance is tested. FIG. 4 shows MoS₂A friction curve diagram of a YSZ composite film, wherein (a) the friction curve changes after irradiation of a non-annealed film; (b) the friction curve changes after the annealed film is irradiated.

The results of the rotating friction experiment show that the average friction coefficient of the annealed film after heavy ion irradiation is lower than 0.04, and the wear rate is 2.5 × 10^-16m³N.m, longer than 2 × 10⁵And (200 min). The heat treated film has a greatly reduced MoS as compared to the untreated film₂The sensitivity of the crystal to heavy ion irradiation greatly reduces irradiation defects and simultaneously maintains the low friction and high wear resistance of the film. Thus, the heat treatment process realizes MoS₂Low friction and radiation resistant self-adaptive integration of/YSZ-based composite filmAnd (4) transforming.

The reason why the film of the present invention has the above properties is that: MoS obtained by radio frequency magnetron sputtering₂The crystals are affected by doping elements in MoS₂A large amount of intrinsic defects such as vacancies, dislocations and the like, MoS, exist in the crystal₂Will be greatly reduced in crystallinity, MoS₂The crystal unsaturation increases. Defect enriched MoS₂The crystals are easy to generate collision cascade in the heavy ion irradiation process, and finally become amorphous; the MoS can be greatly eliminated by the treatment of the thermal annealing experiment₂Compared with an unannealed film, the dislocation threshold of atoms such as Mo, S and the like is increased, so that the occurrence of a large number of collision cascades in the irradiation process is effectively avoided, and the MoS is greatly improved₂Radiation stability of the crystals. Thermally annealed MoS₂The YSZ film forms a typical hard-to-soft nano-structure material after heavy ion irradiation, and the structure film has excellent tribological properties.

Drawings

FIG. 1 shows MoS₂XRD spectrum of/YSZ film. Wherein (a) the XRD spectrum changes after the unannealed film is irradiated; (b) the XRD spectrogram changes after the annealing film irradiation.

FIG. 2 shows MoS₂XPS spectrum of YSZ film. Wherein (a) the XPS spectrum changes after irradiation of the unannealed film; (b) and the XPS spectrogram changes after the annealing film irradiation.

FIG. 3 shows MoS₂HRTEM image of/YSZ composite film cross section. Wherein (a) a topographic map of the unannealed film after irradiation; (b) and (5) a topographic map after the annealing film is irradiated.

FIG. 4 shows MoS₂Friction curve diagram of/YSZ composite film. Wherein (a) the friction curve changes after irradiation of the unannealed film; (b) the friction curve of the annealed film after irradiation changes.

Detailed Description

The MoS of the invention is illustrated by the following specific examples₂The preparation and properties of the/YSZ films are further illustrated.

The equipment used was: the RF magnetron sputtering system was manufactured by Shenkou instruments Inc., Chinese academy of sciences, model No. JS-600. The system mainly comprises a deposition chamber, a substrate plate, a direct current power supply, two radio frequency power supplies, a bias power supply and a set of vacuum pumping devices, wherein the sputtering power supply is connected with a target material, and the bias voltage is connected with a substrate. The annealing equipment is prepared by the combined fertilizer and crystal material technology company Limited, and the model is OTF-1200X.

Cleaning a silicon substrate: and (2) placing the monocrystalline silicon (001) in anhydrous acetone for ultrasonic cleaning for 10min, then placing the monocrystalline silicon in anhydrous ethanol for cleaning for 10min, drying the monocrystalline silicon by using an air gun, and then placing the monocrystalline silicon in a deposition chamber.

Vacuumizing: firstly, pumping the air pressure of the chamber to be within 10Pa by using a mechanical pump, closing the mechanical pump, starting the molecular pump, and simultaneously starting the substrate heating device.

Plasma cleaning, namely, when the vacuum pressure is less than 1.3 × 10^-3And when Pa is needed, controlling the substrate temperature at 150 ℃, introducing argon gas, controlling the argon gas flow rate at 40sccm, adjusting the gas pressure to 3Pa, adding the substrate bias voltage to-400V, and carrying out plasma cleaning on the surface of the sample for 10 min.

And (3) deposition of a Ti transition layer: after cleaning, removing the bias voltage of the substrate, keeping the argon flow rate unchanged (controlling the argon flow at 40 sccm), adjusting the working pressure of the chamber to be 0.65Pa by controlling the inserting plate valve, and adjusting the distance between the target and the substrate to be 60-80 cm; controlling the current of the Ti target at 0.5A, and depositing a Ti transition layer with the thickness of 200nm on a silicon substrate;

MoS₂deposition of/YSZ composite film: MoS₂Selecting MoS with the purity of 99.9% as the target material₂ZrO in YSZ target₂:Y₂O₃5at% of 95: 80 mm. The argon flow is controlled at 40sccm, the working pressure is adjusted to 0.65Pa, and the substrate bias is removed. MoS₂The target deposition power was maintained at 250W, the YSZ target deposition power was maintained at 150W, and the coating was carried out for 120 minutes. After deposition, the chamber temperature was cooled to 60 ℃ and the sample was removed.

Heat treatment, cooling to room temperature after deposition, taking out the sample and placing in a muffle furnace (annealing equipment), pumping the pressure in the furnace to within 10Pa by a mechanical pump, closing the mechanical pump, opening a molecular pump until the vacuum pressure is less than 6.7 × 10^- ⁷When mbar occurs, the heating device is started, and the temperature in the furnace is heated from 30 ℃ for 57minKeeping the temperature at 600 ℃ for 1 min. After the furnace body temperature is cooled to room temperature, taking out a sample MoS₂a/YSZ composite film.

Sample MoS₂The thickness of the/YSZ composite film is 6um, the film has stronger radiation damage resistance on the structure, and good crystallinity is still kept after 2MeV heavy ion irradiation; the sample is proved to have good radiation resistance.

Using GCr15 as a dual, under the vacuum environment, the rotating speed is 1000r/min, the rotating radius is 3 mm, and the sample MoS₂The friction coefficient of the/YSZ composite film is lower than 0.04, and the wear rate is 2.5 × 10^-16m³/N.m。

Claims

1. A process for preparing the Mo/Y stabilized zirconium oxide film with high antiwear and antiradiation performance includes such steps as washing the substrate, preparing MoS by RF-magnetron sputtering physical vapor deposition₂a/YSZ composite film, then MoS₂Thermal annealing treatment is carried out on the/YSZ composite film to eliminate MoS₂The intrinsic defects of the crystal in the magnetron sputtering growth process obtain the molybdenum disulfide/yttrium stabilized zirconia composite film with excellent friction performance and irradiation resistance.

2. The method for preparing the molybdenum disulfide/yttrium-stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 1, wherein: and the cleaning is to place the substrate material in anhydrous acetone and alcohol for cleaning for 15-20 min in sequence and blow-drying.

3. The method for preparing the molybdenum disulfide/yttrium-stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 1, wherein: the radio frequency magnetron sputtering physical vapor deposition technology is used for preparing MoS₂the/YSZ composite film is prepared by placing the cleaned substrate material on the chassis of a multi-target magnetron sputtering device, and vacuumizing to 1.3 × 10^-3Pa, introducing argon, and carrying out Ar under the condition that the substrate is biased to 400V⁺Ion cleaning to remove oxide on the surface of the substrate; firstly using DC sputteringDepositing a Ti transition layer with the thickness of 100-300 nm; co-sputtering MoS under the condition of no substrate bias voltage₂Coating with a YSZ target for 90-120 minutes; obtaining MoS₂a/YSZ film; then MoS₂the/YSZ film is placed in annealing equipment for thermal annealing treatment.

4. The method for preparing the molybdenum disulfide/yttrium-stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 3, wherein: ar (Ar)⁺In the ion cleaning, the substrate temperature is controlled at 100-150 ℃, the argon flow is controlled at 40sccm, and the air pressure is adjusted to 7.5 Pa.

5. The method for preparing the molybdenum disulfide/yttrium-stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 3, wherein: in the direct current sputtering deposition of the Ti transition layer, the deposition gas is Ar gas, the working pressure is 0.65Pa, and the working current of the Ti target is 0.5A.

6. The method for preparing the molybdenum disulfide/yttrium-stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 3, wherein: co-sputtering MoS₂In coating with YSZ target, MoS₂Selecting MoS with the purity of 99.9% as the target material₂ZrO in YSZ target₂:Y₂O₃5at% of 95: 60-80 mm of target base distance.

7. The method for preparing the molybdenum disulfide/yttrium-stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 3, wherein: co-sputtering MoS₂In the YSZ target coating film, the argon flow rate is controlled at 40sccm, and the working pressure is kept at 0.65 Pa.

8. The method for preparing the molybdenum disulfide/yttrium-stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 3, wherein: MoS₂The target deposition power is kept at 200-250W, the YSZ target deposition power is kept at 100-150W, and the film deposition time is keptControlling the temperature to be 1.5-2 h to obtain MoS₂The thickness of the/YSZ film is 4-6 um.

9. The method for preparing the molybdenum disulfide/yttrium stabilized zirconia composite film with high wear resistance and radiation resistance as claimed in claim 3, wherein during the annealing process, the vacuum is finally pumped to 6.7 × 10^-7Par, heating from room temperature to 600 ℃ over 57 minutes, and keeping the temperature for 1 minute; and after the annealing is finished, cooling to room temperature to obtain the product, namely the molybdenum disulfide/yttrium stabilized zirconia composite film.