CN107338407B - Preparation method of tungsten carbide-cobalt wear-resistant coating - Google Patents

Preparation method of tungsten carbide-cobalt wear-resistant coating Download PDF

Info

Publication number
CN107338407B
CN107338407B CN201710506848.5A CN201710506848A CN107338407B CN 107338407 B CN107338407 B CN 107338407B CN 201710506848 A CN201710506848 A CN 201710506848A CN 107338407 B CN107338407 B CN 107338407B
Authority
CN
China
Prior art keywords
tungsten carbide
graphene
coating
powder
spraying
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
Application number
CN201710506848.5A
Other languages
Chinese (zh)
Other versions
CN107338407A (en
Inventor
田浩亮
崔永静
郭孟秋
汤智慧
王长亮
高俊国
张欢欢
周子民
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AECC Beijing Institute of Aeronautical Materials
Original Assignee
AECC Beijing Institute of Aeronautical Materials
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by AECC Beijing Institute of Aeronautical Materials filed Critical AECC Beijing Institute of Aeronautical Materials
Priority to CN201710506848.5A priority Critical patent/CN107338407B/en
Publication of CN107338407A publication Critical patent/CN107338407A/en
Application granted granted Critical
Publication of CN107338407B publication Critical patent/CN107338407B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
    • C23C4/126—Detonation spraying
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
    • C23C4/06—Metallic material

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Lubricants (AREA)
  • Coating By Spraying Or Casting (AREA)
  • Carbon And Carbon Compounds (AREA)

Abstract

The invention discloses a preparation method of a tungsten carbide-cobalt wear-resistant coating, which comprises the following steps: step 1: weighing the graphene modified tungsten carbide self-lubricating wear-resistant additive, adding the graphene modified tungsten carbide self-lubricating wear-resistant additive into WC-12Co spraying powder, and ball-grinding in an absolute ethyl alcohol medium; step 2: and carrying out ultrasonic dispersion treatment on the mixed powder containing the liquid medium after ball milling for hours, drying the powder after ultrasonic treatment, and screening to obtain spraying powder. And step 3: preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen to acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s; and 4, step 4: and performing polishing treatment after spraying a coating on the surface. The graphene coating material can not be blown away by high-speed and high-temperature spraying flame flow to be lost, and the component content and the uniform distribution of graphene in the coating are effectively kept.

Description

Preparation method of tungsten carbide-cobalt wear-resistant coating
Technical Field
The invention belongs to the field of graphene modified tungsten carbide composite materials, and particularly relates to a preparation method of a tungsten carbide-cobalt wear-resistant coating.
Background
The hot spraying tungsten carbide coating has the advantages of high microhardness, good wear resistance, low oxide content, high coating bonding strength and the like, is a common wear-resistant coating, and is widely applied to wear-resistant protection of the surfaces of equipment key friction kinematic pair parts in the industrial fields of aviation, aerospace, nuclear energy, machinery and the like. However, in an actual working environment, due to the higher hardness of the tungsten carbide coating, the friction coefficient of a friction system is higher, so that the friction pair matched with the tungsten carbide coating is seriously abraded, and the service life of the wear-resistant protective coating is even influenced. In addition, with the technological progress, the industrial production is increasingly developed towards high automation and high speed, many parts (such as bearings, bushings, sealing rings, piston rods and the like) often work under severe environmental conditions of heavy load, high speed, high temperature, low temperature, high vacuum, strong corrosion and the like, and the environment not only exceeds the use limit of lubricating oil or grease, but also limits the application of the tungsten carbide coating, so that the tungsten carbide coating with self-lubricating property needs to be developed to meet the service requirements under extreme friction conditions.
The tungsten carbide spraying powder is the basis for preparing the tungsten carbide wear-resistant coating by thermal spraying, and in order to prepare the tungsten carbide wear-resistant coating with self-lubricating property, a self-lubricating additive must be added into the tungsten carbide spraying powder, the self-lubricating agent added into the spraying powder at present mainly comprises soft metals (Au, Ag and the like), fluorides (LiF2, CaF2 and the like), disulfides (MoS2, WS2 and the like) and metal oxides (Zr2O3, Cr2O3 and the like), and the prior art has conducted many researches on the lubricants used as the lubricating phases of the coatings. However, these additives have some limitations, such as that sulfide added in the coating is easily oxidized in lubrication compatibility with the increase of temperature during the friction process, the tribological performance is seriously reduced, and the additive is especially serious in a humid environment; although fluorides of alkaline earth metals and rare metals have high-temperature self-lubricating properties, they have poor tribological properties at low temperatures and exhibit brittleness.
Through long-term research and analysis, the graphene is a new carbonaceous material with a single-layer two-dimensional honeycomb lattice structure formed by tightly accumulating carbon atoms, is a basic unit for constructing the most common solid lubricant graphite, has a lower friction coefficient than graphite, and is a novel self-lubricating antifriction coating additive. However, graphene is a carbon material with a nanoscale single-layer structure, the weight is light, the ceramic tungsten carbide spraying powder is large in weight, and if the graphene is directly added into the tungsten carbide spraying powder, the graphene is blown away by high-speed flame flow in the spraying process and is lost, so that the graphene component is difficult to remain in a recoating layer. In addition, the graphene has large specific surface area and high activity, is easy to agglomerate when being compounded with tungsten carbide spraying powder, and is difficult to ensure uniform mixing in the spraying powder, so that the prepared coating has self-lubricating wear-resistant property. Therefore, how to increase the specific gravity of the graphene in the tungsten carbide spraying powder and ensure the uniform mixing in the spraying powder is the main technical content of the invention.
Accordingly, the prior art is deficient and needs improvement.
Disclosure of Invention
The invention aims to provide a preparation method of a tungsten carbide-cobalt wear-resistant coating, which adopts the following technical scheme for realizing the aim:
a preparation method of a tungsten carbide-cobalt wear-resistant coating comprises the following steps:
step 1: weighing the graphene modified tungsten carbide self-lubricating wear-resistant additive, adding the graphene modified tungsten carbide self-lubricating wear-resistant additive into WC-12Co spraying powder, and ball-grinding in an absolute ethyl alcohol medium;
step 2: carrying out ultrasonic dispersion treatment on the mixed powder containing the liquid medium after ball milling for hours, drying the powder after ultrasonic treatment, and screening to obtain spraying powder;
and step 3: preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen to acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s;
and 4, step 4: and performing polishing treatment after spraying a coating on the surface.
In the step 1, 2 to 10g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention is weighed and added into 200gWC to 12Co spraying powder, and ball milling is carried out in an absolute ethyl alcohol medium for 10 hours, wherein the rotating speed of the ball mill is 3 rpm/s.
In the step 2, the mixed powder containing the liquid medium after ball milling is subjected to ultrasonic dispersion treatment for 2 hours, and the powder after ultrasonic treatment is dried at 40 ℃ for 2 hours and then is screened to obtain the spraying powder with the particle size of 25-45 μm.
In the above, in the step 4, the final thickness of the coating after polishing is 0.2 mm.
Compared with the closest prior art, the invention has the following beneficial effects:
1) according to the technical scheme provided by the invention, nano tungsten carbide particles which are dispersedly distributed can be grown in situ on the surface of the lamellar graphene, and the size, the shape and the content of the nano tungsten carbide particles grown in situ on the surface of the graphene can be regulated and controlled by controlling the content ratio of reactants and reaction conditions.
2) Compared with the method that graphene is directly added into tungsten carbide spraying powder as a self-lubricating agent, the graphene modified carbide self-lubricating agent prepared by the method has the advantages that the characteristics of a graphene lamellar carbon structure unit are not changed, the graphene still has the advantages of large specific surface area, high activity and the like, the weight of the graphene is improved to a great extent, and the nano tungsten carbide loaded with in-situ growth on the surface improves the compatibility and the uniform mixing with the tungsten carbide spraying powder.
3) Compared with a tungsten carbide coating prepared by directly adding graphene into tungsten carbide spraying powder without modification, the graphene modified tungsten carbide self-lubricating agent obtained by the invention cannot be blown away by high-speed and high-temperature spraying flame flow and lost in the spraying process, and effectively keeps the component content and uniform distribution of the graphene in the coating.
4) The graphene modified tungsten carbide self-lubricating wear-resistant additive is applied to a wear-resistant coating, on one hand, the strength and toughness of the coating can be improved by graphene, in addition, the shearing force between graphene sheet layers is extremely small, and the relative sliding between the graphene sheet layers in the friction process can replace the relative sliding of a metal piece on the surface of a friction pair, so that the separation of abrasive dust and the surface of the friction pair is realized, the friction coefficient is greatly reduced, and the wear is reduced.
Drawings
FIG. 1 is an X-ray diffraction diagram of the graphene modified tungsten carbide self-lubricating wear-resistant additive.
Fig. 2 is a scanning electron microscope image of the graphene-modified tungsten carbide self-lubricating wear-resistant additive.
FIG. 3 is a high-power scanning electron microscope image of the graphene-modified tungsten carbide self-lubricating wear-resistant additive.
Fig. 4 is a scanning electron microscope image of the graphene-modified tungsten carbide self-lubricating wear-resistant additive uniformly mixed in the tungsten carbide spray powder.
Fig. 5 is a scanning electron microscope image of a fracture of the graphene-modified tungsten carbide self-lubricating wear-resistant coating prepared in the embodiment of the invention.
Fig. 6 is another scanning electron microscope image of a fracture of the graphene-modified tungsten carbide self-lubricating wear-resistant coating prepared in the embodiment of the invention.
FIG. 7 is a friction coefficient curve diagram of a tungsten carbide coating prepared by thermal spraying and a wear-resistant coating compounded with the graphene-modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
the invention relates to a graphene modified tungsten carbide self-lubricating wear-resistant additive and a preparation process thereof, wherein the preparation process comprises the following steps: a certain amount of graphite powder was added to a solution consisting of concentrated H2SO4(12mL), K2S2O8(2.5g) and P2O5(2.5g) and reacted at 80 ℃ for 4.5 hours. Then cooled to room temperature and 0.5L deionized water was added. And dried at normal temperature. This pre-oxidized graphite powder was added to 150mL of concentrated H2SO4, the environment was maintained at 0 ℃ with an ice-water bath, 15g of KMnO4 was gradually added while maintaining the temperature at 20 ℃ or less, and after the addition was completed, stirring was carried out at 35 ℃ for 2 hours. Then 250mL of deionized water was added and stirred for 2 hours. 0.7L of deionized water was then added, followed by 30 mL of 30% H2O2, dried at room temperature, and dialyzed against a dialysis bag for 1 week to remove the hetero-ions. And finally, carrying out vacuum filtration, and drying at normal temperature to obtain the graphene oxide.
Weighing 1g of graphene oxide, adding 1000g of absolute ethyl alcohol, uniformly stirring and mixing, adding 50g of deionized water, mixing, selecting a 10mm amplitude rod in an ultrasonic disperser, carrying out ultrasonic treatment for 30min at an ultrasonic frequency of 10Hz to obtain a graphene-dispersed mixed solution, respectively weighing 99% by mass of ammonium metatungstate and 1% by mass of tungsten carbonyl to obtain a tungsten-containing precursor mixture, weighing 1g of the tungsten-containing precursor mixture, adding the tungsten-containing precursor mixture into the graphene-dispersed solution, stirring for 30min, continuously dripping absolute ethyl alcohol in the stirring process, dripping 18g of absolute ethyl alcohol, then carrying out suction filtration on the obtained precipitate, heating to 70 ℃ in an oven, drying for 10min, placing the obtained dry powder in an alumina crucible, introducing a certain amount of H2 into a tubular reduction furnace, wherein the flow rate of H2 is l00sccm, heating to 700 ℃ at a heating rate of 5 ℃/min, keeping the temperature for 1H, and finally, cooling to room temperature through H2 to obtain the self-lubricating wear-resistant additive of the graphene modified tungsten carbide.
The process for preparing the tungsten carbide-cobalt wear-resistant coating containing the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention by thermal spraying comprises the following steps:
weighing 2g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention, adding the weighed graphene modified tungsten carbide self-lubricating wear-resistant additive into 200gWC-12Co spraying powder, carrying out ball milling for 10 hours in an absolute ethyl alcohol medium, wherein the rotating speed of the ball mill is 3 rpm/s, carrying out ultrasonic dispersion treatment on mixed powder containing a liquid medium after ball milling for 2 hours, drying the powder at 40 ℃ for 2 hours after ultrasonic treatment, and screening out the spraying powder with the granularity of 25-45 mu m.
Preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen and acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s. The friction test is carried out on a CETR fretting friction wear testing machine in a ball-surface contact mode, the load is 10N, the upper sample is a GCrl5 steel ball with the diameter of 6.5mm, the lower sample is a disc surface spraying coating with the length of 24.9 mm multiplied by 7.8mm, and the final thickness of the coating after polishing is 0.2 mm.
The test parameters are as follows: the abrasion time is 10min, the frequency is 30 Hz, and the displacement amplitude D is 2 mm.
The tungsten carbide coating prepared in this example had an average coefficient of friction of 0.65 and a loss on wear of 3.7 mg. The average friction coefficient of the prepared graphene modified WC-Co coating is 0.47, and the abrasion weight loss is 2.1 mg. The research result shows that: the friction coefficient of the graphene modified coating is lower than that of the WC-12Co coating, which shows that the graphene modified self-lubricating wear-resistant additive prepared by the invention has better self-lubricating property on the tungsten carbide coating. In addition, the abrasion loss of the graphene modified self-lubricating wear-resistant coating is smaller than that of the original tungsten carbide coating, which shows that the graphene modified self-lubricating wear-resistant additive prepared by the invention has the functions of reducing abrasion and resisting wear on the tungsten carbide coating.
As shown in fig. 1, which is an XRD pattern of the graphene-modified tungsten carbide self-lubricating wear-resistant additive prepared in this example, it can be seen that all characteristic peaks in the pattern are completely consistent with the phase of WC, and the surface of the graphene is loaded with the phase of WC.
As shown in fig. 2, which is a scanning electron microscope image of the in-situ grown tungsten carbide nanoparticles on the surface of the graphene prepared in this example, it can be seen that the white nano-sized tungsten carbide particles are uniformly distributed on the surface of the graphene, and the original lamellar structure characteristics of the graphene are not damaged.
As shown in fig. 3, which is a high-power scanning electron microscope image of the in-situ grown tungsten carbide particles on the surface of the graphene prepared in this example, it can be seen that the size of the tungsten carbide particles is between 10 nm and 20nm, which proves that the tungsten carbide particles have small size and uniform distribution.
Fig. 4 is a scanning electron microscope image of uniform powder of the graphene-modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention in tungsten carbide spray powder, and arrows in the image show that graphene is tightly adhered to the surface of the spray powder to achieve better compatibility.
Fig. 5 and fig. 6 show scanning electron microscope images of fractures of the graphene-modified tungsten carbide self-lubricating wear-resistant coating prepared by the invention, and arrows in the images show that graphene is tightly embedded in the coating to achieve better compatibility.
Fig. 7 shows the friction coefficient curves of the tungsten carbide coating prepared in this example and the wear-resistant coating compounded with the graphene-modified tungsten carbide self-lubricating wear-resistant additive prepared in the invention.
Example 2:
on the basis of the foregoing embodiments, this embodiment provides a preparation process of the graphene-modified tungsten carbide self-lubricating wear-resistant additive, which is as follows: a certain amount of graphite powder was added to a solution consisting of concentrated H2SO4(12mL), K2S2O8(2.5g) and P2O5(2.5g) and reacted at 80 ℃ for 4.5 hours. Then cooled to room temperature and 0.5L deionized water was added. And dried at normal temperature. This pre-oxidized graphite powder was added to 150mL of concentrated H2SO4, the environment was maintained at 0 ℃ with an ice-water bath, 15g of KMnO4 was gradually added while maintaining the temperature at 20 ℃ or less, and after the addition was completed, stirring was carried out at 35 ℃ for 2 hours. Then 250mL of deionized water was added and stirred for 2 hours. 0.7L of deionized water was then added, followed by 30 mL of 30% H2O2, dried at room temperature, and dialyzed against a dialysis bag for 1 week to remove the hetero-ions. And finally, carrying out vacuum filtration, and drying at normal temperature to obtain the graphene oxide.
Weighing 2g of graphene oxide, adding 1000g of absolute ethyl alcohol, uniformly stirring and mixing, adding 60g of deionized water, mixing, selecting a 10mm amplitude rod in an ultrasonic disperser, carrying out ultrasonic treatment for 60min at an ultrasonic frequency of 12Hz to obtain a graphene-dispersed mixed solution, respectively weighing 99% by mass of ammonium metatungstate and 1% by mass of tungsten carbonyl to obtain a tungsten-containing precursor mixture, weighing 1g of the tungsten-containing precursor mixture, adding the tungsten-containing precursor mixture into the graphene-dispersed solution, stirring for 40min, continuously dripping absolute ethyl alcohol in the stirring process, wherein the dripping amount is 84g, then carrying out suction filtration on the obtained precipitate, heating the precipitate in an oven at 80 ℃, drying for 20min, placing the obtained dry powder in an alumina crucible, introducing a certain amount of H2 into a tubular reduction furnace, wherein the flow rate of H2 is l00sccm, heating the precipitate to 700 ℃ at a heating rate of 20 ℃/min, keeping the temperature for 1H, and finally, cooling to room temperature through H2 to obtain the self-lubricating wear-resistant additive of the graphene modified tungsten carbide.
The process for preparing the tungsten carbide-cobalt wear-resistant coating containing the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention by thermal spraying comprises the following steps:
weighing 4g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention, adding the additive into 200gWC-12Co spraying powder, carrying out ball milling in an absolute ethyl alcohol medium for 10 hours at the rotating speed of 3 rpm/s, carrying out ultrasonic dispersion treatment on mixed powder containing a liquid medium after ball milling for 2 hours, drying the powder at 40 ℃ for 2 hours after ultrasonic treatment, and screening out the spraying powder with the granularity of 25-45 mu m.
Preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen and acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s. The friction test is carried out on a CETR fretting friction wear testing machine in a ball-surface contact mode, the load is 10N, the upper sample is a GCrl5 steel ball with the diameter of 6.5mm, the lower sample is a disc surface spraying coating with the length of 24.9 mm multiplied by 7.8mm, and the final thickness of the coating after polishing is 0.2 mm.
The test parameters are as follows: the abrasion time is 10min, the frequency is 30 Hz, and the displacement amplitude D is 2 mm.
The tungsten carbide coating prepared in this example had an average coefficient of friction of 0.67 and a loss on wear of 3.4 mg. The average friction coefficient of the prepared graphene modified WC-Co coating is 0.45, and the abrasion weight loss is 2.7 mg. The research result shows that: the friction coefficient of the graphene modified coating is lower than that of the WC-12Co coating, which shows that the graphene modified self-lubricating wear-resistant additive prepared by the invention has better self-lubricating property on the tungsten carbide coating. In addition, the abrasion loss of the graphene modified self-lubricating wear-resistant coating is smaller than that of the original tungsten carbide coating, which shows that the graphene modified self-lubricating wear-resistant additive prepared by the invention has the functions of reducing abrasion and resisting wear on the tungsten carbide coating.
Example 3:
on the basis of the foregoing embodiment, the embodiment provides a preparation process of a graphene-modified tungsten carbide self-lubricating wear-resistant additive, which is as follows: a certain amount of graphite powder was added to a solution consisting of concentrated H2SO4(12mL), K2S2O8(2.5g) and P2O5(2.5g) and reacted at 80 ℃ for 4.5 hours. Then cooled to room temperature and 0.5L deionized water was added. And dried at normal temperature. This pre-oxidized graphite powder was added to 150mL of concentrated H2SO4, the environment was maintained at 0 ℃ with an ice-water bath, 15g of KMnO4 was gradually added while maintaining the temperature at 20 ℃ or less, and after the addition was completed, stirring was carried out at 35 ℃ for 2 hours. Then 250mL of deionized water was added and stirred for 2 hours. 0.7L of deionized water was then added, followed by 30 mL of 30% H2O2, dried at room temperature, and dialyzed against a dialysis bag for 1 week to remove the hetero-ions. And finally, carrying out vacuum filtration, and drying at normal temperature to obtain the graphene oxide.
Weighing 3g of graphene oxide, adding 1000g of absolute ethyl alcohol, uniformly stirring and mixing, adding 700g of deionized water, mixing, selecting a 10mm amplitude rod in an ultrasonic disperser, carrying out ultrasonic treatment for 120min at an ultrasonic frequency of 12Hz to obtain a graphene-dispersed mixed solution, weighing 99% of ammonium metatungstate and 1% of tungsten carbonyl in percentage by mass respectively to obtain a tungsten-containing precursor mixture, weighing 1g of the tungsten-containing precursor mixture, adding the tungsten-containing precursor mixture into the graphene-dispersed solution, stirring for 50min, continuously dripping absolute ethyl alcohol in the stirring process, wherein the dripping amount is 168g, then carrying out suction filtration on the obtained precipitate, heating the precipitate in an oven at 80 ℃, drying for 20min, placing the obtained dry powder in an alumina crucible, introducing a certain amount of H2 into a tubular reduction furnace, wherein the flow rate of H2 is l00sccm, heating the precipitate to 800 ℃ at a heating rate of 30 ℃/min, keeping the temperature for 2H, and finally, cooling to room temperature through H2 to obtain the self-lubricating wear-resistant additive of the graphene modified tungsten carbide.
The process for preparing the tungsten carbide-cobalt wear-resistant coating containing the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention by thermal spraying comprises the following steps:
weighing 6g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention, adding the additive into 200gWC-12Co spraying powder, carrying out ball milling for 10 hours in an absolute ethyl alcohol medium, wherein the rotating speed of the ball mill is 3 rpm/s, carrying out ultrasonic dispersion treatment on mixed powder containing a liquid medium after ball milling for 2 hours, drying the powder at 40 ℃ for 2 hours after ultrasonic treatment, and screening out spraying powder with the particle size of 25-45 microns.
Preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen and acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s. The friction test is carried out on a CETR fretting friction wear testing machine in a ball-surface contact mode, the load is 10N, the upper sample is a GCrl5 steel ball with the diameter of 6.5mm, the lower sample is a disc surface spraying coating with the length of 24.9 mm multiplied by 7.8mm, and the final thickness of the coating after polishing is 0.2 mm.
The test parameters are as follows: the abrasion time is 10min, the frequency is 30 Hz, and the displacement amplitude D is 2 mm.
The tungsten carbide coating prepared in this example had an average coefficient of friction of 0.62 and a loss on wear of 3.5 mg. The average friction coefficient of the prepared graphene modified WC-Co coating is 0.40, and the abrasion weight loss is 2.2 mg. The research result shows that: the friction coefficient of the graphene modified coating is lower than that of the WC-12Co coating, and the friction coefficient of the prepared graphene modified self-lubricating wear-resistant coating tends to be reduced along with the increase of the content of the graphene modified self-lubricating wear-resistant additive in the tungsten carbide powder.
Example 4:
on the basis of the foregoing embodiment, the embodiment provides a preparation process of a graphene-modified tungsten carbide self-lubricating wear-resistant additive, which is as follows: a certain amount of graphite powder was added to a solution consisting of concentrated H2SO4(12mL), K2S2O8(2.5g) and P2O5(2.5g) and reacted at 80 ℃ for 4.5 hours. Then cooled to room temperature and 0.5L deionized water was added. And dried at normal temperature. This pre-oxidized graphite powder was added to 150mL of concentrated H2SO4, the environment was maintained at 0 ℃ with an ice-water bath, 15g of KMnO4 was gradually added while maintaining the temperature at 20 ℃ or less, and after the addition was completed, stirring was carried out at 35 ℃ for 2 hours. Then 250mL of deionized water was added and stirred for 2 hours. 0.7L of deionized water was then added, followed by 30 mL of 30% H2O2, dried at room temperature, and dialyzed against a dialysis bag for 1 week to remove the hetero-ions. And finally, carrying out vacuum filtration, and drying at normal temperature to obtain the graphene oxide.
Weighing 4g of graphene oxide, adding 1000g of absolute ethyl alcohol, uniformly stirring and mixing, adding 800g of deionized water, mixing, selecting a 10mm amplitude rod in an ultrasonic disperser, carrying out ultrasonic treatment for 150min at an ultrasonic frequency of 15Hz to obtain a graphene-dispersed mixed solution, respectively weighing 99% by mass of ammonium metatungstate and 1% by mass of tungsten carbonyl to form a tungsten-containing precursor mixture, weighing 1g of the tungsten-containing precursor mixture, adding the tungsten-containing precursor mixture into the graphene-dispersed solution, stirring for 60min, continuously dropping absolute ethyl alcohol in the stirring process, wherein the dropping amount is 228g, then carrying out suction filtration on the obtained precipitate, heating to 90 ℃ in an oven, drying for 40min, placing the obtained dry powder in an alumina crucible, introducing a certain amount of H2 into a tubular reduction furnace, wherein the flow rate of H2 is l00sccm, heating to 900 ℃ at a heating rate of 50 ℃/min, keeping the temperature for 2H, and finally, cooling to room temperature through H2 to obtain the self-lubricating wear-resistant additive of the graphene modified tungsten carbide.
The process for preparing the tungsten carbide-cobalt wear-resistant coating containing the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention by thermal spraying comprises the following steps:
weighing 8g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention, adding the additive into 200gWC-12Co spraying powder, carrying out ball milling in an absolute ethyl alcohol medium for 10 hours at the rotating speed of 3 rpm/s, carrying out ultrasonic dispersion treatment on mixed powder containing a liquid medium after ball milling for 2 hours, drying the powder at 40 ℃ for 2 hours after ultrasonic treatment, and screening out the spraying powder with the granularity of 25-45 mu m.
Preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen and acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s. The friction test is carried out on a CETR fretting friction wear testing machine in a ball-surface contact mode, the load is 10N, the upper sample is a GCrl5 steel ball with the diameter of 6.5mm, the lower sample is a disc surface spraying coating with the length of 24.9 mm multiplied by 7.8mm, and the final thickness of the coating after polishing is 0.2 mm.
The test parameters are as follows: the abrasion time is 10min, the frequency is 30 Hz, and the displacement amplitude D is 2 mm.
The tungsten carbide coating prepared in this example had an average coefficient of friction of 0.65 and a loss on wear of 3.9 mg. The average friction coefficient of the prepared graphene modified WC-Co coating is 0.42, and the abrasion weight loss is 2.4 mg. The research result shows that: the friction coefficient of the graphene modified coating is lower than that of the WC-12Co coating, which shows that the graphene modified self-lubricating wear-resistant additive prepared by the invention has better self-lubricating property on the tungsten carbide coating.
Example 5:
on the basis of the foregoing embodiment, the embodiment provides a preparation process of a graphene-modified tungsten carbide self-lubricating wear-resistant additive, which is as follows: a certain amount of graphite powder was added to a solution consisting of concentrated H2SO4(12mL), K2S2O8(2.5g) and P2O5(2.5g) and reacted at 80 ℃ for 4.5 hours. Then cooled to room temperature and 0.5L deionized water was added. And dried at normal temperature. This pre-oxidized graphite powder was added to 150mL of concentrated H2SO4, the environment was maintained at 0 ℃ with an ice-water bath, 15g of KMnO4 was gradually added while maintaining the temperature at 20 ℃ or less, and after the addition was completed, stirring was carried out at 35 ℃ for 2 hours. Then 250mL of deionized water was added and stirred for 2 hours. 0.7L of deionized water was then added, followed by 30 mL of 30% H2O2, dried at room temperature, and dialyzed against a dialysis bag for 1 week to remove the hetero-ions. And finally, carrying out vacuum filtration, and drying at normal temperature to obtain the graphene oxide.
Weighing 5g of graphene oxide, adding 1000g of absolute ethyl alcohol, uniformly stirring and mixing, adding 800g of deionized water, mixing, selecting a 10mm amplitude rod in an ultrasonic disperser, carrying out ultrasonic treatment for 150min at an ultrasonic frequency of 15Hz to obtain a graphene-dispersed mixed solution, weighing 99% of ammonium metatungstate and 1% of tungsten carbonyl in percentage by mass respectively to obtain a tungsten-containing precursor mixture, weighing 1g of the tungsten-containing precursor mixture, adding the tungsten-containing precursor mixture into the graphene-dispersed solution, stirring for 60min, continuously dropping absolute ethyl alcohol in the stirring process, wherein the dropping amount is 286g, then carrying out suction filtration on the obtained precipitate, heating to 90 ℃ in an oven, drying for 40min, placing the obtained dry powder in an alumina crucible, introducing a certain amount of H2 into a tubular reduction furnace, wherein the flow rate of H2 is l00sccm, heating to 900 ℃ at a heating rate of 50 ℃/min, keeping the temperature for 2H, and finally, cooling to room temperature through H2 to obtain the self-lubricating wear-resistant additive of the graphene modified tungsten carbide.
The process for preparing the tungsten carbide-cobalt wear-resistant coating containing the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention by thermal spraying comprises the following steps:
weighing 8g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention, adding the additive into 200gWC-12Co spraying powder, carrying out ball milling in an absolute ethyl alcohol medium for 10 hours at the rotating speed of 3 rpm/s, carrying out ultrasonic dispersion treatment on mixed powder containing a liquid medium after ball milling for 2 hours, drying the powder at 40 ℃ for 2 hours after ultrasonic treatment, and screening out the spraying powder with the granularity of 25-45 mu m.
Preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen and acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s. The friction test is carried out on a CETR fretting friction wear testing machine in a ball-surface contact mode, the load is 10N, the upper sample is a GCrl5 steel ball with the diameter of 6.5mm, the lower sample is a disc surface spraying coating with the length of 24.9 mm multiplied by 7.8mm, and the final thickness of the coating after polishing is 0.2 mm.
The test parameters are as follows: the abrasion time is 10min, the frequency is 30 Hz, and the displacement amplitude D is 2 mm.
The tungsten carbide coating prepared in this example had an average coefficient of friction of 0.68 and a loss on wear of 3.6 mg. The average friction coefficient of the prepared graphene modified WC-Co coating is 0.44, and the abrasion weight loss is 2.6 mg. The research result shows that: the friction coefficient of the graphene modified coating is lower than that of the WC-12Co coating, which shows that the graphene modified self-lubricating wear-resistant additive prepared by the invention has better self-lubricating property on the tungsten carbide coating.
Example 6:
on the basis of the foregoing embodiment, the embodiment provides a preparation process of a graphene-modified tungsten carbide self-lubricating wear-resistant additive, which is as follows: a certain amount of graphite powder was added to a solution consisting of concentrated H2SO4(12mL), K2S2O8(2.5g) and P2O5(2.5g) and reacted at 80 ℃ for 4.5 hours. Then cooled to room temperature and 0.5L deionized water was added. And dried at normal temperature. This pre-oxidized graphite powder was added to 150mL of concentrated H2SO4, the environment was maintained at 0 ℃ with an ice-water bath, 15g of KMnO4 was gradually added while maintaining the temperature at 20 ℃ or less, and after the addition was completed, stirring was carried out at 35 ℃ for 2 hours. Then 250mL of deionized water was added and stirred for 2 hours. 0.7L of deionized water was then added, followed by 30 mL of 30% H2O2, dried at room temperature, and dialyzed against a dialysis bag for 1 week to remove the hetero-ions. And finally, carrying out vacuum filtration, and drying at normal temperature to obtain the graphene oxide.
Weighing 6g of graphene oxide, adding 1000g of absolute ethyl alcohol, uniformly stirring and mixing, adding 800g of deionized water, mixing, selecting a 10mm amplitude rod in an ultrasonic disperser, carrying out ultrasonic treatment for 180min at an ultrasonic frequency of 15Hz to obtain a graphene-dispersed mixed solution, respectively weighing 99% by mass of ammonium metatungstate and 1% by mass of tungsten carbonyl to form a tungsten-containing precursor mixture, weighing 1g of the tungsten-containing precursor mixture, adding the tungsten-containing precursor mixture into the graphene-dispersed solution, stirring for 60min, continuously dripping the absolute ethyl alcohol in the stirring process, dripping the absolute ethyl alcohol in an amount of 324g, then carrying out suction filtration on the obtained precipitate, heating the precipitate in an oven at 90 ℃, drying for 40min, placing the obtained dry powder in an alumina crucible, introducing a certain amount of H2 into a tubular reduction furnace at a flow rate of l00sccm at a heating rate of 70 ℃/min, heating to 900 ℃, and keeping the temperature for 3H, and finally, cooling to room temperature through H2 to obtain the self-lubricating wear-resistant additive of the graphene modified tungsten carbide.
The process for preparing the tungsten carbide-cobalt wear-resistant coating containing the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention by thermal spraying comprises the following steps:
weighing 10g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared by the invention, adding the additive into 200gWC-12Co spraying powder, carrying out ball milling for 10 hours in an absolute ethyl alcohol medium, wherein the rotating speed of the ball mill is 3 rpm/s, carrying out ultrasonic dispersion treatment on mixed powder containing a liquid medium after ball milling for 2 hours, drying the powder at 40 ℃ for 2 hours after ultrasonic treatment, and screening out spraying powder with the particle size of 25-45 microns.
Preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen and acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s. The friction test is carried out on a CETR fretting friction wear testing machine in a ball-surface contact mode, the load is 10N, the upper sample is a GCrl5 steel ball with the diameter of 6.5mm, the lower sample is a disc surface spraying coating with the length of 24.9 mm multiplied by 7.8mm, and the final thickness of the coating after polishing is 0.2 mm.
The test parameters are as follows: the abrasion time is 10min, the frequency is 30 Hz, and the displacement amplitude D is 2 mm.
The tungsten carbide coating prepared in this example had an average coefficient of friction of 0.65 and a loss on wear of 3.5 mg. The average friction coefficient of the prepared graphene modified WC-Co coating is 0.39, and the abrasion weight loss is 2.1 mg. The research result shows that: the friction coefficient of the graphene modified coating is lower than that of the WC-12Co coating, which shows that the graphene modified self-lubricating wear-resistant additive prepared by the invention has better self-lubricating property on the tungsten carbide coating.
The wear-resistant coating compounded with the graphene modified tungsten carbide self-lubricating additive prepared based on the thermal spraying technology has the beneficial effects that the wear-resistant coating prepared based on the graphene modified tungsten carbide self-lubricating additive can be applied to the existing easily-worn parts to play a role in reducing and resisting wear, and can also be applied to a piston rod of an aircraft landing gear or a hydraulic transmission component (a plunger, a piston and a connecting rod) in engineering machinery to replace the existing electroplated hard chromium component, so that the environmental pollution of hexavalent chromium particles can be avoided, the friction coefficient and the wear rate in the friction process of the coating are greatly reduced, and the service life of the parts is prolonged. Therefore, the self-lubricating wear-resistant protection device can be widely applied to self-lubricating wear-resistant protection of parts with harsh friction working conditions in the aerospace field.
It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.

Claims (1)

1. A preparation method of a tungsten carbide-cobalt wear-resistant coating is characterized by comprising the following steps:
step 1: preparing a graphene modified tungsten carbide self-lubricating wear-resistant additive;
step 2: weighing the graphene modified tungsten carbide self-lubricating wear-resistant additive, adding the graphene modified tungsten carbide self-lubricating wear-resistant additive into WC-12Co spraying powder, and carrying out ball milling in an absolute ethyl alcohol medium;
and step 3: performing ultrasonic dispersion treatment on the mixed powder containing the liquid medium after ball milling, drying and screening the powder after ultrasonic treatment to obtain spraying powder;
and 4, step 4: preparing the graphene modified coating by adopting explosion spraying, wherein the process parameters are as follows: the flow ratio of oxygen to acetylene is 1.2, the gas gun filling amount is 68%, the spraying distance is 260mm, the explosion frequency is adjusted to be 3 times/second, and the powder feeding rate is 0.3 g/s;
and 5: polishing the surface sprayed coating;
in the step 1, the preparation process of the graphene modified tungsten carbide self-lubricating wear-resistant additive comprises the following steps: weighing 1g of graphene oxide, adding 1000g of absolute ethyl alcohol, uniformly stirring and mixing, adding 50g of deionized water, mixing, selecting a 10mm amplitude rod in an ultrasonic dispersion instrument, carrying out ultrasonic treatment for 30min, wherein the ultrasonic frequency is 10Hz, obtaining a mixed solution with dispersed graphene, respectively weighing 99% ammonium metatungstate and 1% tungsten carbonyl in percentage by mass to form a precursor mixture containing tungsten, weighing 1g of the precursor mixture containing tungsten, adding the precursor mixture into the graphene dispersion solution, stirring for 30min, and stirringContinuously dripping anhydrous ethanol in an amount of 18g, vacuum filtering the obtained precipitate, heating at 70 deg.C in oven, oven drying for 10min, placing the obtained dried powder in alumina crucible, and introducing a certain amount of H in tubular reduction furnace2，H2Heating to 700 deg.C at a temperature rise rate of 5 deg.C/min with a flow rate of l00sccm, holding for 1H, and introducing H2Cooling to room temperature to obtain the graphene modified tungsten carbide self-lubricating wear-resistant additive;
in the step 2, 2-10 g of the graphene modified tungsten carbide self-lubricating wear-resistant additive prepared in the step 1 is weighed and added into 200gWC-12Co spraying powder, and ball milling is carried out in an absolute ethyl alcohol medium for 10 hours;
in the step 3, performing ultrasonic dispersion treatment on the mixed powder containing the liquid medium after ball milling for 2 hours, drying the powder after ultrasonic treatment for 2 hours at 40 ℃, and screening out spraying powder with the particle size of 25-45 microns;
in the step 5, the final thickness of the coating after polishing is 0.2 mm.
CN201710506848.5A 2017-06-28 2017-06-28 Preparation method of tungsten carbide-cobalt wear-resistant coating Active CN107338407B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710506848.5A CN107338407B (en) 2017-06-28 2017-06-28 Preparation method of tungsten carbide-cobalt wear-resistant coating

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710506848.5A CN107338407B (en) 2017-06-28 2017-06-28 Preparation method of tungsten carbide-cobalt wear-resistant coating

Publications (2)

Publication Number Publication Date
CN107338407A CN107338407A (en) 2017-11-10
CN107338407B true CN107338407B (en) 2021-03-16

Family

ID=60221026

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710506848.5A Active CN107338407B (en) 2017-06-28 2017-06-28 Preparation method of tungsten carbide-cobalt wear-resistant coating

Country Status (1)

Country Link
CN (1) CN107338407B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160043408A1 (en) * 2014-08-08 2016-02-11 Samsung Electronics Co., Ltd. Composite for lithium air battery, method of preparing the composite, and lithium air battery employing positive electrode including the composite
CN106513659A (en) * 2015-10-29 2017-03-22 中国航空工业集团公司北京航空材料研究院 Preparation method for graphene-modified self-lubricating wear-resistant coating
CN106521394A (en) * 2015-10-29 2017-03-22 中国航空工业集团公司北京航空材料研究院 Graphene modified self-lubricating wear-resistant coating

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160043408A1 (en) * 2014-08-08 2016-02-11 Samsung Electronics Co., Ltd. Composite for lithium air battery, method of preparing the composite, and lithium air battery employing positive electrode including the composite
CN106513659A (en) * 2015-10-29 2017-03-22 中国航空工业集团公司北京航空材料研究院 Preparation method for graphene-modified self-lubricating wear-resistant coating
CN106521394A (en) * 2015-10-29 2017-03-22 中国航空工业集团公司北京航空材料研究院 Graphene modified self-lubricating wear-resistant coating

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
氧化石墨烯表面原位生长纳米碳化钨工艺及形貌;田浩亮等;《金属热处理》;20170625;第42卷(第6期);第196-200页 *

Also Published As

Publication number Publication date
CN107338407A (en) 2017-11-10

Similar Documents

Publication Publication Date Title
CN107350470B (en) Modified graphene-containing tungsten carbide spraying powder for preparing self-lubricating wear-resistant coating
Arenas et al. Tribological behaviour of laser textured Ti6Al4V alloy coated with MoS2 and graphene
Liu et al. Tribological behavior and self-healing functionality of M50 material covered with surface micropores filled with Sn-Ag-Cu
Yao et al. High temperature tribological behaviors and wear mechanisms of NiAl-MoO3/CuO composite coatings
Pan et al. Synthesis and tribological behavior of oil-soluble Cu nanoparticles as additive in SF15W/40 lubricating oil
Essa et al. Studies on the effect of applied load, sliding speed and temperature on the wear behavior of M50 steel reinforced with Al2O3 and/or graphene nanoparticles
Chen et al. Composition versus friction and wear behavior of plasma sprayed WC–(W, Cr) 2C–Ni/Ag/BaF2–CaF2 self-lubricating composite coatings for use up to 600° C
De Mello et al. Effect of precursor content and sintering temperature on the scuffing resistance of sintered self lubricating steel
Xin et al. Effect of silver vanadate on the lubricating properties of NiCrAlY laser cladding coating at elevated temperatures
Kavimani et al. Tribo-surface characteristics and wear behaviour of SiC@ r-GO/Mg composite worn under varying control factor
Xin et al. Effect of copper molybdate on the lubricating properties of NiCrAlY laser clad coating at elevated temperatures
Guan et al. Preparation and tribological behaviors of magnesium silicate hydroxide-MoS2 nanoparticles as lubricant additive
Li et al. Tribological behavior of ZrO2/WS2 coating surfaces with biomimetic shark-skin structure
Yang et al. Tribological behaviors of plasma sprayed CuAl/Ni-graphite composite coating
Liu et al. Tribological properties of adaptive phosphate composite coatings with addition of silver and molybdenum disulfide
Lifan et al. Effect of MoS2 mass fraction on microstructure and tribological characteristics of laser cladded Cu–10Al coating
Liu et al. Study on self-adaptive lubrication mechanism of surface micro-dimple structure filled with multiple lubricants
Juszczyk et al. Tribological properties of copper-based composites with lubricating phase particles
Srivyas et al. Effect of load on the tribological behavior of self-lubricating hybrid aluminum composite under dry sliding conditions
Yan et al. Enhanced extreme pressure lubrication performance and load carrying capability of gallium-based liquid metal reinforced with MoSe2 and WSe2 nanoparticles
Chen et al. Development of wear resistant Cu-12Sn-1.5 Ni alloy via minor addition of Fe during casting process
Shekhar et al. Fabrication and self-lubricating tribological characterisation of Cu–Ni/TiC/CaF2 composite for railway switch slide baseplate
Chkhartishvili et al. Hexagonal boron nitride as a solid lubricant additive (an overview)
Wang et al. Friction and wear characteristics of containing a certain amount of graphene oxide (GO) for hot-pressing sintered NiCr-WC-Al2O3 composites at different temperatures
Miao et al. Recent progress on the tribological applications of solid lubricants

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