CN110923610A - Preparation method of cobalt-based alloy composite powder and cladding coating for plasma spraying - Google Patents
Preparation method of cobalt-based alloy composite powder and cladding coating for plasma spraying Download PDFInfo
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- 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
- C23C4/134—Plasma spraying
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- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
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- B22F1/06—Metallic powder characterised by the shape of the particles
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- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/14—Making metallic powder or suspensions thereof using physical processes using electric discharge
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- C—CHEMISTRY; METALLURGY
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- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
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- 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
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- C23C4/06—Metallic material
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- 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
- C23C4/073—Metallic material containing MCrAl or MCrAlY alloys, where M is nickel, cobalt or iron, with or without non-metal elements
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Abstract
The invention relates to cobalt-based composite powder for plasma spraying, which is prepared from the following raw materials in parts by weight: 90-120 parts of cobalt-based alloy powder, 3-5 parts of yttrium oxide powder, 7-12 parts of titanium boride powder and 10-15 parts of chromium carbide powder; after being treated by radio frequency induction plasma spheroidizing equipment, all the powder is mechanically and uniformly mixed to obtain subsphaeroidal cobalt-based composite powder; and discloses a method for manufacturing the cladding coating of the hydraulic prop piston rod by plasma spraying. The treatment of radio frequency induction plasma spheroidizing equipment and the optimization of plasma spraying process parameters are adopted to obtain the alloy with high bonding strength and hardness, good wear resistance and corrosion resistance and reduced cracking sensitivity of a cladding coating; the service life of the piston rod of the hydraulic prop is prolonged. Meanwhile, the method can also be applied to the protection of other components.
Description
Technical Field
The invention belongs to the field of coatings, and particularly relates to cobalt-based alloy composite powder for plasma spraying and a preparation method of a cladding coating.
Background
The piston rod of the hydraulic prop moves back and forth frequently under the pressure of hydraulic oil, the working condition under a mine is severe, the relative humidity is high, and sulfide and other corrosive media exist, so that the surface of the piston rod of the upright post of the hydraulic support is easy to corrode; meanwhile, fine coal grindstone can be generated to rub the surface of the piston rod, and the service life of the hydraulic support is further influenced. Every year, a large number of hydraulic support upright column piston rods are scrapped due to failure caused by corrosion and abrasion, so that the surface corrosion resistance, abrasion resistance and the like of the hydraulic support upright column piston rods need to be improved.
Patent CN103866221A discloses a remanufacturing process of an induction preheating melt coating of a piston rod of a support type coal mine hydraulic support, which mainly adopts the induction preheating melt coating process to coat a nickel-based self-fluxing alloy wear-resistant and corrosion-resistant coating on the surface of an old piston rod. Patent CN107502850A discloses a processing method for improving the wear resistance of a piston rod of an automobile shock absorber, which comprises surface treatment of a workpiece to be treated, intermediate powder preparation, mixed powder preparation and plasma spraying. Compared with the prior art, the invention has the following advantages: the processed product has high bonding strength with the base body, the shock resistance and the wear resistance are obviously improved, and the service life of the piston rod of the automobile shock absorber is prolonged. Patent CN1403710A discloses a method for hardening ceramic on the surface of a piston rod, which aims to solve the technical problems: at present, piston rods are produced through more than ten cold and hot processing procedures, and the piston rods are long in production period, high in cost and low in qualified product rate. The content of the invention is as follows: forging → normalizing → rough machining → tempering → semi-finishing → stress relief tempering → rough grinding → ceramic spraying → finishing. The ceramic treatment greatly reduces the time of the hot working process, reduces the rejection rate, and greatly prolongs the service life of the piston rod due to the wear resistance and corrosion resistance of the ceramic. Patent CN109182946A discloses a wear-resistant, corrosion-resistant and medium-high temperature-resistant coating formula for a hydraulic hoist piston rod, which comprises the following components in percentage by mass: SiO 22Powder: 2 to 8 percent of TiO2Powder: 2 to 6% of Y2O3Powder: 2 to 8% of Cr2O3Powder: and (4) the balance. The formula is used as a spraying raw material, and a wear-resistant, corrosion-resistant and medium-high temperature resistant coating for a hydraulic hoist piston rod can be obtained by adopting high-enthalpy plasma spraying, has excellent wear-resistant and corrosion-resistant properties, and can resist medium-high temperature of 600-800 DEG CAnd the coating has high surface hardness and strong binding force with a base material, can bear larger load, and effectively solves the problems that the existing coating is easy to peel off, corrode and wear, and is in service at 600-800 ℃ in a high-temperature environment.
Although the prior art has made many researches through the technologies of laser cladding, spraying and the like, the phenomena of cracking, falling off, corrosion and the like are easy to occur in the actual production process. Therefore, how to obtain a composite coating with high adhesive force, high coating hardness, wear resistance, corrosion resistance and low cracking sensitivity is still the direction of research in the prior art.
Disclosure of Invention
The invention aims to provide a preparation method of cobalt-based composite powder for plasma spraying and a cladding coating prepared from the composite powder, so as to overcome the defects of the existing composite coating in the background technology, improve the bonding force, hardness, wear resistance and corrosion resistance of the cladding coating on the surface of a hydraulic prop piston rod, reduce the cracking sensitivity and prolong the service life of the hydraulic prop piston rod.
In order to achieve the purpose, the invention provides the following technical scheme: a cobalt-based composite powder for plasma spraying is prepared from the following raw materials in parts by weight: 90-120 parts of cobalt-based alloy powder, 3-5 parts of yttrium oxide powder, 7-12 parts of titanium boride powder and 10-15 parts of chromium carbide powder; the preparation method comprises the following specific steps:
(1) adopting radio frequency induction plasma spheroidizing equipment, spraying 50-65 mu m of cobalt-based alloy powder into a plasma torch by using Ar as carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the cobalt-based alloy powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 5-10L/min, sheath gas N2Flow rate: 25-40L/min, carrier gas Ar flow: 20-30L/min, power: 15-30kW, powder feeding rate: 25-35 g/min; collecting to obtain subsphaeroidal cobalt-based alloy powder;
(2) adopting radio frequency induction plasma spheroidizing equipment, spraying 15-30 μm yttrium oxide powder into plasma flame by using Ar as carrier gas through feeding gunIn the torch, the powder instantly absorbs a large amount of heat to be melted and spheroidized, the spherical liquid drops are rapidly cooled and solidified in the argon atmosphere, and finally, the yttrium oxide powder is collected at the bottom of the spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 20-30L/min, sheath gas N2Flow rate: 40-50L/min, carrier gas Ar flow: 60-75L/min, power: 50-70kW, powder feeding rate: 20-35 g/min; collecting to obtain approximately spherical yttrium oxide powder;
(3) adopting radio frequency induction plasma spheroidizing equipment, injecting titanium diboride powder with the particle size of 20-40 mu m into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in the argon atmosphere, and finally collecting the titanium diboride powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 45-60L/min, sheath gas N2Flow rate: 30-50L/min, carrier gas Ar flow: 25-45L/min, power: 80-100kW, powder feeding rate: 25-40 g/min; collecting to obtain near-spherical titanium diboride powder;
(4) adopting radio frequency induction plasma spheroidizing equipment, injecting 20-30 mu m of chromium carbide powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the chromium carbide powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 25-35L/min, sheath gas N2Flow rate: 40-50L/min, carrier gas Ar flow: 35-45L/min, power: 20-50kW, powder feeding rate: 25-40 g/min; collecting to obtain near-spherical chromium carbide powder;
(5) and (3) mechanically and uniformly mixing the subsphaeroidal cobalt-based alloy powder, the yttrium oxide powder, the titanium diboride powder and the chromium carbide powder obtained in the steps (2) to (4) according to the parts by weight, and drying in a vacuum drying oven at the temperature of 60-80 ℃ for 20-40min to obtain the cobalt-based composite powder for plasma spraying.
Preferably, the cobalt-based alloy powder is selected from one of Stellite 6 or tellite 12.
A preparation method for manufacturing a cladding coating of a hydraulic prop piston rod by plasma spraying comprises the following steps:
(1) oil removal: firstly, sequentially placing the matrix material to be sprayed in absolute ethyl alcohol and acetone, respectively cleaning for 10-20 minutes under the action of ultrasonic waves, taking out, and drying for later use.
(2) Sand blasting treatment: adopting silicon carbide sand with the granularity of 40-70 meshes, wherein the sand blasting angle is as follows: 90-120 °, blasting distance: 100-: 0.3-0.6MPa, and the surface roughness after sand blasting is controlled to be 8-12 mu m.
(3) Atmospheric plasma spraying of the bonding layer: preheating a substrate to 120-180 ℃, and spraying a NiCoCrAlY bonding layer on the surface of the substrate subjected to sand blasting by using plasma, wherein the plasma spraying process parameters are that the spraying distance is 110-130 mm, and the spraying current is as follows: 200-250A, argon flow: 35-50L/min, powder feeding rate: 10-15g/min, bonding layer thickness: 10-25 μm.
(4) Supersonic plasma spraying cladding coating: after the composite NiCrAlY bonding layer is sprayed, the cobalt-based composite powder is sprayed by supersonic plasma; the parameters of the supersonic plasma spraying process are that the spraying current is 300-: 80-100L/min, and auxiliary gas H2Flow rate: 30-50L/min, powder feeding amount: 40-60g/min, cladding coating thickness: 0.2-0.5 mm.
(5) And (4) grinding and polishing the sprayed hydraulic prop piston rod to obtain a cladding layer with the surface roughness of 5-8 mu m.
Preferably, the NiCoCrAlY bonding layer is formed of: 20-24 wt% of Co, 12-17 wt% of Cr, 7-11 wt% of Al, 0.5-0.8 wt% of Y and the balance of Ni.
The invention has the following beneficial effects: (1) the addition of carbide, boride and other hard phases into the plasma spraying powder can improve the hardness and wear resistance of the cladding coating to a certain extent, but because the ceramic phase has a very high melting point (the melting point of titanium diboride is as high as 2930 ℃), and the thermal expansion coefficient, elastic modulus and thermal conductivity coefficient of the matrix are very different, large thermal stress is caused at the plasma spraying temperature, and thus the defects of coating cracks, falling and the like are easily caused. The rare earth oxide has good purification effect on crystal boundary impurities and can have strong affinity with impurity elements such as oxygen, hydrogen and the likeThe effect of promoting the tissue loosening of the impurity elements is inhibited, and pores, inclusions and cracks in the cladding layer are obviously reduced. The chromium carbide powder has the functions of solid solution strengthening and passivation, can improve the corrosion resistance and the high-temperature oxidation resistance, and forms Cr at high temperature of plasma spraying23C6、Cr7C3Hard phases such as chromium boride and the like, thereby improving the hardness and the wear resistance of the alloy.
However, the use of yttrium oxide powder and chromium carbide powder still cannot effectively reduce the cracking sensitivity. Therefore, the cobalt-based composite powder for plasma spraying is obtained by uniformly mixing cobalt-based alloy powder, yttrium oxide powder, titanium diboride powder and silicon carbide powder through radio frequency induction plasma spheroidization respectively. Through the spheroidizing treatment of the radio frequency induction plasma, the composite powder has excellent fluidity and wettability, is favorable for uniform powder feeding during plasma cladding, finally forms good metallurgical bonding with a matrix alloy, and effectively avoids the cracking of the coating while improving the wear resistance of the coating.
(2) The hydraulic prop piston rod is prepared by uniformly mixing cobalt-based alloy powder, yttrium oxide powder, titanium diboride powder and silicon carbide powder through radio frequency induction plasma spheroidization respectively and then performing plasma spraying, and the spheroidization parameters and the plasma spraying process parameters of the powder are optimally controlled through a large amount of experimental researches, so that the structure of the obtained cobalt-based alloy coating is more uniform and compact, the hardness, the wear resistance and the corrosion performance of the cladding layer are improved, the combination of the cladding layer and a matrix is also ensured, the defects of cracking, falling and the like of the cladding layer are reduced, and the service life of the hydraulic prop piston rod is greatly prolonged.
(3) Before spraying, the substrate is subjected to sand blasting treatment, so that the surface of the clean substrate forms an uneven surface and meets a certain roughness requirement. The roughened surface and the coating can produce better mechanical bonding. After sand blasting, when the substrate is sprayed, the fused powder particles are mutually occluded with the surface of the substrate, so that the bonding area of the coating and the substrate is increased, the residual stress of the coating is reduced, and the cracking sensitivity can be reduced.
(4) The preheating of the surface of the base metal can reduce and prevent the increase of internal stress, but the preheating temperature cannot be too high, and the excessive temperature can easily cause the oxidation of the surface and influence the bonding strength of the coating and the surface of the base; the low temperature does not achieve the purpose of preheating, so the preheating temperature of the workpiece is properly selected in the spraying process. Improper temperature selection can cause excessive temperature differences between the coating and the substrate surface during spraying, resulting in greater shrinkage stress of the coating, which can cause cracking or even spalling of the coating. Therefore, the proper selection of the preheating treatment of the surface of the metal substrate is an important measure for effectively preventing or reducing the occurrence of defects such as peeling and low bonding strength.
Drawings
The invention will be further described with reference to the accompanying drawings.
Fig. 1 is a schematic view of the rf-induced plasma sphering apparatus of the present invention.
FIG. 2 is a scanning electron micrograph of the powder and the plasma spray clad coating of example 1 and comparative example 1.
In the figure: 1. the device comprises a feeding gun, 2, central gas, 3, sheath gas, 4, a radio frequency power supply, 5, a plasma torch, 6, induction plasma, 7, a vacuum gauge, 8, a vacuum pump, 9, a water-cooling cavity, 10 and a cavity bottom.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious 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
A cobalt-based composite powder for plasma spraying is prepared from the following raw materials in parts by weight: 100 parts of cobalt-based alloy powder, 5 parts of yttrium oxide powder, 7 parts of titanium boride powder and 12 parts of chromium carbide powder.
The preparation method comprises the following specific steps:
(1) a radio frequency induction plasma spheroidizing device is adopted, 65-micron Stellite 6 cobalt-based alloy powder is sprayed into a plasma torch by a feeding gun by using Ar as carrier gas, the powder instantly absorbs a large amount of heat to be melted and spheroidized, spherical liquid drops are rapidly cooled and solidified in the argon atmosphere, and finally the cobalt-based alloy powder is collected at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 10L/min, sheath gas N2Flow rate: 40L/min, carrier gas Ar flow: 30L/min, power: 20kW, powder feeding rate: 25 g/min; and collecting to obtain the near-spherical cobalt-based alloy powder.
(2) Adopting radio frequency induction plasma spheroidizing equipment, spraying 25 mu m of yttrium oxide powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the yttrium oxide powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 25L/min, sheath gas N2Flow rate: 45L/min, carrier gas Ar flow: 75L/min, power 60kW, powder feeding rate: 25 g/min; and collecting to obtain the approximately spherical yttrium oxide powder.
(3) Adopting radio frequency induction plasma spheroidizing equipment, spraying 30 mu m titanium diboride powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the titanium diboride powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 45L/min, sheath gas N2Flow rate: 30L/min, carrier gas Ar flow: 30L/min, power: 80kW, powder feeding rate: 30 g/min; and collecting to obtain the near-spherical titanium diboride powder.
(4) Adopting radio frequency induction plasma spheroidizing equipment, injecting 20 mu m of chromium carbide powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the chromium carbide powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 30L/min, sheath gas N2Flow rate: 45L/min, carrier gas Ar flow: 45L/min, power:40kW, powder feeding rate: 40 g/min; and collecting to obtain the near-spherical chromium carbide powder.
(5) And (3) mechanically and uniformly mixing the subsphaeroidal cobalt-based alloy powder, the yttrium oxide powder, the titanium diboride powder and the chromium carbide powder obtained in the steps (2) to (4) according to the parts by weight, and drying in a vacuum drying oven at 70 ℃ for 40min to obtain the cobalt-based composite powder for plasma spraying.
A method for manufacturing a cladding coating of a hydraulic prop piston rod by plasma spraying comprises the following steps:
(1) oil removal: firstly, sequentially placing the base material to be sprayed in absolute ethyl alcohol and acetone, respectively cleaning for 15 minutes under the action of ultrasonic waves, taking out and drying for later use.
(2) Sand blasting treatment: adopting white corundum sand with the granularity of 80 meshes, and the sand blasting angle is as follows: 80 degrees, sand blasting distance: 140mm, air pressure: 0.7MPa, and the surface roughness after sand blasting is controlled to be 12 mu m.
(3) Atmospheric plasma spraying of the bonding layer: preheating a substrate to 180 ℃, and spraying a NiCoCrAlY bonding layer on the surface of the substrate subjected to sand blasting by adopting plasma, wherein the plasma spraying process parameters are as follows: 120mm, spray current: 250A, argon flow: 40L/min, powder feeding rate: 15g/min, and the thickness of the bonding layer is 18 mu m.
(4) Supersonic plasma spraying cladding coating: after the NiCoCrAlY bonding layer is sprayed, the cobalt-based composite powder is sprayed by supersonic plasma; the technological parameters of the supersonic plasma spraying are that the spraying current is 450A, and the spraying voltage is as follows: 120V, main gas Ar flow: 80L/min, auxiliary gas H2Flow rate: 40-60L/min, powder feeding amount: 40g/min, cladding coating thickness: 0.25 mm.
(5) And (4) grinding and polishing the sprayed hydraulic prop piston rod to obtain a cladding layer with the surface roughness of 3.5 microns.
Example 2
A cobalt-based composite powder for plasma spraying is prepared from the following raw materials in parts by weight: 110 parts of cobalt-based alloy powder, 4 parts of yttrium oxide powder, 10 parts of titanium boride powder and 10 parts of chromium carbide powder.
The preparation method comprises the following specific steps:
(1) a radio frequency induction plasma spheroidizing device is adopted, 55 mu m of Stellite 6 cobalt-base alloy powder is sprayed into a plasma torch by using Ar as a carrier gas through a feeding gun, the powder instantly absorbs a large amount of heat to be melted and spheroidized, spherical liquid drops are rapidly cooled and solidified in the argon atmosphere, and finally the cobalt-base alloy powder is collected at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 7L/min, sheath gas N2Flow rate: 30L/min, carrier gas Ar flow: 25L/min, power: 25kW, powder feeding rate: 30 g/min; and collecting to obtain the near-spherical cobalt-based alloy powder.
(2) Adopting radio frequency induction plasma spheroidizing equipment, spraying 30 mu m of yttrium oxide powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the yttrium oxide powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 20L/min, sheath gas N2Flow rate: 40L/min, carrier gas Ar flow: 65L/min, power: 50kW, powder feeding rate: 20 g/min; and collecting to obtain the approximately spherical yttrium oxide powder.
(3) Adopting radio frequency induction plasma spheroidizing equipment, spraying titanium diboride powder with the particle size of 40 mu m into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the titanium diboride powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 555L/min, sheath gas N2Flow rate: 40L/min, carrier gas Ar flow: 40L/min, power 90kW, powder feeding rate: 35 g/min; and collecting to obtain the near-spherical titanium diboride powder.
(4) Adopting radio frequency induction plasma spheroidizing equipment, injecting 30 mu m of chromium carbide powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the chromium carbide powder at the bottom of a spheroidizing reactor. Spheroidization parameters are central gas Ar flow: 25L/min, sheathGas N2Flow rate: 40L/min, carrier gas Ar flow: 35L/min, power 35kW, powder feeding rate: 30 g/min; and collecting to obtain the near-spherical chromium carbide powder.
(5) And (3) mechanically and uniformly mixing the subsphaeroidal cobalt-based alloy powder, the yttrium oxide powder, the titanium diboride powder and the chromium carbide powder obtained in the steps (2) to (4) according to the parts by weight, and drying in a vacuum drying oven at 80 ℃ for 30min to obtain the cobalt-based composite powder for plasma spraying.
A method for manufacturing a cladding coating of a hydraulic prop piston rod by plasma spraying comprises the following steps:
(1) oil removal: firstly, sequentially placing the base material to be sprayed in absolute ethyl alcohol and acetone, respectively cleaning for 15 minutes under the action of ultrasonic waves, taking out and drying for later use.
(2) Sand blasting treatment: adopting white corundum sand with the granularity of 80 meshes, and the sand blasting angle is as follows: 76 °, blasting distance: 120mm, air pressure: 0.8MPa, and the surface roughness after sand blasting is controlled to be 15 mu m.
(3) Atmospheric plasma spraying of the bonding layer: preheating a substrate to 150 ℃, and spraying a NiCoCrAlY bonding layer on the surface of the substrate subjected to sand blasting by using plasma, wherein the plasma spraying process parameters are that the spraying distance is 130mm, and the spraying current is as follows: 200A, argon flow: 35L/min, powder feeding rate: 15g/min, bonding layer thickness: 15 μm.
(4) Supersonic plasma spraying cladding coating: after the NiCoCrAlY bonding layer is sprayed, the cobalt-based composite powder is sprayed by supersonic plasma; the technological parameters of the supersonic plasma spraying are that the spraying current is 400A, and the spraying voltage is as follows: 100V, main gas Ar flow: 100L/min; auxiliary gas H2Flow rate: 40L/min, powder feeding amount: 30g/min, cladding coating thickness: 0.15 mm.
(5) And (4) grinding and polishing the sprayed hydraulic prop piston rod to obtain a cladding layer with the surface roughness of 4.5 microns.
Comparative example 1
A cobalt-based composite powder for plasma spraying is prepared from the following raw materials in parts by weight: 100 parts of cobalt-based alloy powder, 5 parts of yttrium oxide powder, 7 parts of titanium boride powder and 12 parts of chromium carbide powder. The specific size and the selection of the powder are the same as those of the embodiment 1, except that the comparative example 1 does not carry out induction plasma spheroidization treatment, and the cobalt-based alloy powder, the yttrium oxide powder, the titanium boride powder and the chromium carbide powder are mechanically and uniformly mixed according to the parts by weight and then dried in a vacuum drying oven at 70 ℃ for 40min to obtain the cobalt-based composite powder for plasma spraying.
A method for manufacturing a cladding coating of a hydraulic prop piston rod by plasma spraying has the same preparation steps as example 1, and only differs from cobalt-based composite powder. And (4) grinding and polishing the sprayed hydraulic prop piston rod to obtain a cladding layer with the surface roughness of 12.7 microns.
Comparative example 2
A cobalt-based composite powder for plasma spraying is prepared from the following raw materials in parts by weight: 110 parts of cobalt-based alloy powder, 4 parts of yttrium oxide powder, 10 parts of titanium boride powder and 10 parts of chromium carbide powder. The specific size and the selection of the powder are the same as those of the embodiment 2, except that the comparative example 2 does not carry out induction plasma spheroidization treatment, and the cobalt-based alloy powder, the yttrium oxide powder, the titanium boride powder and the chromium carbide powder are mechanically and uniformly mixed according to the parts by weight, and then dried in a vacuum drying oven at 80 ℃ for 30min to obtain the cobalt-based composite powder for plasma spraying.
The preparation steps of the method for manufacturing the cladding coating of the hydraulic prop piston rod by plasma spraying are the same as those of the embodiment 2, and only the cobalt-based composite powder is different. And (4) grinding and polishing the sprayed hydraulic prop piston rod to obtain a cladding layer with the surface roughness of 13.1 microns.
The invention is characterized mainly in example 1 and comparative example 1 to illustrate the main concept of the invention.
The powders obtained in example 1 and comparative example 1 were observed microscopically by a scanning electron microscope. Fig. 1 is an SEM image of a cobalt-based composite powder obtained in example 1, and fig. 2 is an SEM image of a cobalt-based composite powder obtained in a comparative example. As can be seen from the SEM image, the cobalt-based composite powder treated by the invention has a nearly spherical shape, and the powder has no agglomeration phenomenon, thereby demonstrating that the powder has good fluidity.
The evaluation of the bonding strength index of the invention is carried out by preparing samples and testing according to GB/T8642-2002 national standard for measuring tensile bonding strength of thermal spraying. Five groups of samples were tested for each coating, and the five groups were averaged to obtain their bond strength values. The hardness is a comprehensive index for representing the coating, and the high hardness is favorable for improving the wear resistance of the coating to a certain extent. The method adopts a Vickers hardness tester to test the hardness of the interface of the cladding coating, the test condition is 0.98N load and 15s of holding time, the points in 6 areas are randomly tested, and the average value is taken as the hardness value of the cladding coating. In the friction and wear test, a HT-1000 type ball disc type high-temperature friction and wear testing machine is adopted to carry out dry friction test, and the friction coefficient at room temperature is obtained through test treatment. According to GB/T10125-2012 salt spray test for artificial atmosphere corrosion test, the salt spray corrosion resistance of the cladding coating is analyzed by observing the corrosion morphology of the cladding layer and measuring the mass loss of the cladding layer. The salt spray test is carried out by degreasing, derusting, absolute ethyl alcohol cleaning and drying before weighing. In a salt spray corrosion box, a hanging piece continuous spraying mode is adopted for carrying out a salt spray test, the mass fraction of a NaCl solution is 5%, the pH value is 3.0-3.1, and the temperature is 35 ℃. And measuring the residual stress of the cladding coating by adopting an X-ray diffraction method. The results of the experiments are reported in table 1.
TABLE 1
Bonding Strength (MPa) | Hardness (HV)0.1) | Coefficient of friction | Corrosion resistance time (h) | Residual stress (MPa) | |
Example 1 | 68.4 | 1325 | 0.25 | 2671 | -335 |
Comparative example 1 | 61.1 | 908 | 0.37 | 2044 | -613 |
From the above experimental data it can be derived: the bonding strength of the powder treated by induction plasma spheroidization is slightly higher than that of the powder treated by the comparative example 1 through plasma spraying, and the main reason is that the powder and a matrix form metallurgical bonding through the high spraying temperature of the plasma spraying. The powder treated by induction plasma spheroidization is superior to that of comparative example 1 in salt spray experiment by plasma spraying, and the main reason is that CrB is also formed among cobalt-based alloy powder, yttrium oxide powder, titanium diboride powder and chromium carbide powder in the plasma spraying process2、Cr23C6、Cr7C3The hardness and the corrosion resistance of the coating can be obviously improved by the aid of the equal reinforcing phases; the cladding coating prepared in the example 1 is dense and has no cracks, however, the cladding coating obtained in the comparative example 1 is not as dense as the cladding coating prepared in the example 1 and has obvious cracks, and the cracks make the cladding coating more prone to corrosion in the salt spray experiment. In addition, the cladding coating prepared in example 1 is also superior to that of comparative example 1 in hardness and friction coefficient.
The experimental result of the residual stress also shows that the residual stress of the cladding coating prepared by the spray powder treated by spheroidizing through the radio frequency induction plasma is obviously lower than that of the cladding coating prepared by the comparative example 1. The reduction of the crack sensitivity of the coating after the spheroidizing treatment of the radio frequency induction plasma can be confirmed from the side surface, which is also consistent with the scanning electron microscope image of the cladding coating.
The foregoing description of the embodiments is merely intended to facilitate an understanding of the process and general inventive concept; meanwhile, for those skilled in the art, according to the concept of the present invention, there may be variations in the embodiments and the application scope, and the content of the present specification should not be construed as a limitation of the present invention.
Claims (4)
1. A cobalt-based composite powder for plasma spraying is prepared from the following raw materials in parts by weight: 90-120 parts of cobalt-based alloy powder, 3-5 parts of yttrium oxide powder, 7-12 parts of titanium boride powder and 10-15 parts of chromium carbide powder; the preparation method comprises the following specific steps:
(1) adopting radio frequency induction plasma spheroidizing equipment, spraying 50-65 mu m of cobalt-based alloy powder into a plasma torch by using Ar as carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the cobalt-based alloy powder at the bottom of a spheroidizing reactor; spheroidization parameters are central gas Ar flow: 5-10L/min, sheath gas N2Flow rate: 25-40L/min, carrier gas Ar flow: 20-30L/min, power: 15-30kW, powder feeding rate: 25-35 g/min; collecting to obtain subsphaeroidal cobalt-based alloy powder;
(2) adopting radio frequency induction plasma spheroidizing equipment, spraying 15-30 mu m of yttrium oxide powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the yttrium oxide powder at the bottom of a spheroidizing reactor; spheroidization parameters are central gas Ar flow: 20-30L/min, sheath gas N2Flow rate: 40-50L/min, carrier gas Ar flow: 60-75L/min, power: 50-70kW, and the powder feeding rate is 20-35 g/min; collecting to obtain a near ballForming yttrium oxide powder;
(3) adopting radio frequency induction plasma spheroidizing equipment, spraying titanium diboride powder with the particle size of 20-40 mu m into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the titanium diboride powder at the bottom of a spheroidizing reactor; spheroidization parameters are central gas Ar flow: 45-60L/min, sheath gas N2Flow rate: 30-50L/min, carrier gas Ar flow: 25-45L/min, power: 80-100kW, powder feeding rate 25-40 g/min; collecting to obtain near-spherical titanium diboride powder;
(4) adopting radio frequency induction plasma spheroidizing equipment, injecting 20-30 mu m of chromium carbide powder into a plasma torch by using Ar as a carrier gas through a feeding gun, instantly absorbing a large amount of heat to melt and spheroidize the powder, rapidly cooling and solidifying spherical liquid drops in an argon atmosphere, and finally collecting the chromium carbide powder at the bottom of a spheroidizing reactor; spheroidization parameters are central gas Ar flow: 25-35L/min, sheath gas N2Flow rate: 40-50L/min, carrier gas Ar flow: 35-45L/min, power: 20-50kW, powder feeding rate: 25-40 g/min; collecting to obtain near-spherical chromium carbide powder;
(5) and (3) mechanically and uniformly mixing the subsphaeroidal cobalt-based alloy powder, the yttrium oxide powder, the titanium diboride powder and the chromium carbide powder obtained in the steps (2) to (4) according to the parts by weight, and drying in a vacuum drying oven at the temperature of 60-80 ℃ for 20-40min to obtain the cobalt-based composite powder for plasma spraying.
2. The cobalt-based composite powder for plasma spraying according to claim 1, wherein: the cobalt-based alloy powder is selected from one of Stellite 6 and tellite 12.
3. A preparation method of a cladding coating of a hydraulic strut piston rod comprises the following steps:
(1) oil removal: firstly, sequentially placing the base material to be sprayed in absolute ethyl alcohol and acetone, respectively cleaning for 10-20 minutes under the action of ultrasonic waves, taking out and drying for later use;
(2) sand blasting treatment: adopting white corundum sand with the granularity of 50-100 meshes, wherein the sand blasting angle is as follows: 60-120 °, blasting distance: 80-150mm, air pressure: 0.5-0.8MPa, and the surface roughness is controlled to be 10-15 mu m after sand blasting;
(3) atmospheric plasma spraying of the bonding layer: preheating a substrate to 120-180 ℃, and spraying a NiCoCrAlY bonding layer on the surface of the substrate subjected to sand blasting by using plasma, wherein the plasma spraying process parameters are that the spraying distance is 110-130 mm, and the spraying current is as follows: 200-250A, argon flow: 35-50L/min, powder feeding rate: 10-15g/min, bonding layer thickness: 10-25 μm;
(4) supersonic plasma spraying cladding coating: after the composite NiCoCrAlY bonding layer is sprayed, spraying the cobalt-based composite powder of claims 1-2 by adopting supersonic plasma; the technological parameters of the supersonic plasma spraying are that the spraying current is as follows: 400-450A, spraying voltage: 100-120V, main gas Ar flow: 80-100L/min, and auxiliary gas H2Flow rate: 40-60L/min, powder feeding amount: 30-40g/min, and the thickness of the cladding coating is 0.1-0.3 mm;
(5) and (3) grinding and polishing the sprayed hydraulic prop piston rod to obtain a cladding layer with the surface roughness of 3-5 microns.
4. The preparation method of the cladding coating of the hydraulic prop piston rod according to claim 3, characterized by comprising the following steps: the NiCoCrAlY bonding layer is composed of: 20-24 wt% of Co, 12-17 wt% of Cr, 7-11 wt% of Al, 0.5-0.8 wt% of Y and the balance of Ni.
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CN114082969A (en) * | 2021-11-30 | 2022-02-25 | 中机凯博表面技术江苏有限公司 | Plasma remelting system and process for thermal spraying of ultrafine powder |
CN115478273A (en) * | 2022-09-30 | 2022-12-16 | 沈阳大陆激光工程技术有限公司 | High-wear-resistance cobalt-based alloy material applied to finish rolling side guide plate through laser manufacturing |
CN116217209A (en) * | 2023-03-01 | 2023-06-06 | 洛阳船舶材料研究所(中国船舶集团有限公司第七二五研究所) | AT13 spray-coating feed prepared by plasma spheroidization pretreatment and preparation method thereof |
CN116217209B (en) * | 2023-03-01 | 2024-04-02 | 洛阳船舶材料研究所(中国船舶集团有限公司第七二五研究所) | AT13 spray-coating feed prepared by plasma spheroidization pretreatment and preparation method thereof |
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