Spraying powder for self-adapting wide-temperature-range lubricating coating and preparation method and application thereof

Abstract

The application provides a spraying powder for self-adapting wide-temperature-range lubricating coating, which comprises the following components in percentage by mass: 20-40% of Cr2O3 (BaF2*CaF2); 3-8% of Cu; 3-15% of AgMo; and the balance of MCrAlYX; wherein M in the MCrAlYX is Co and / or Ni, and X is at least one of Ta, Hf and Si. The spraying powder provided by the application has excellent and stable friction coefficients at room temperature to 1000 DEG C, and the friction coefficients are all lower than 0.2. The coating prepared from the spraying powder is suitable for surface lubricating wear-resistant coating of sealing parts of an aero-engine.

Description

Technical Field

[0001] This invention belongs to the field of composite powder preparation technology for thermal spraying, specifically relating to an adaptive wide-temperature-range lubricating coating spraying powder, its preparation method, and its application. Background Technology

[0002] Friction and wear are key technical challenges facing the development of high-tech equipment. Friction can lead to a series of problems such as energy loss, low efficiency, increased temperature and performance degradation. Wear can cause slow and continuous damage to the surface shape and size of parts, gradually reducing the working performance and reliability of high-end equipment, and may even lead to sudden equipment failure.

[0003] Applying a solid self-lubricating and wear-resistant coating to the surface of wear-prone components in high-end equipment via spraying is an effective way to address wear. High-temperature solid lubricating coatings mainly consist of a matrix phase, friction-reducing lubricating components, and wear-resistant components. Metal-based lubricating coatings are currently the most commonly used coating system due to their good compatibility with high-temperature alloy substrates. Current lubricating coatings mainly fall into four categories: refractory metal-based lubricating coatings represented by W and Mo; soft metal lubricating coatings represented by Ag; high-temperature metal-based lubricating coatings represented by Al and Cu; and high-temperature metal-based lubricating wear-resistant coatings represented by Ni and Co. Commonly used solid lubricants include soft metals such as Ag and Pb, layered solids such as MoS2, WS2, and graphite, and substances like CaF2 and BaF2. However, these lubricating coatings only function within a certain temperature range; they fail outside this range and cannot provide lubrication. For example, graphite, MoS2, and the soft metal Ag typically lose their lubricating properties above 500℃, while fluorides and some inorganic acid salts lack lubricating properties at low temperatures. High-temperature machinery, such as aero-engines, requires continuous operation from room temperature to high temperatures in practical applications. Therefore, wear-resistant coatings must possess wide-temperature-range lubrication capabilities. Domestic and international scholars have discovered that the synergistic effect of using multiple solid lubricants can achieve wide-temperature-range lubrication and friction reduction. NASA's PS series of lubricating and wear-resistant coatings uses nickel-based alloys as the matrix phase and Ag / BaF2•CaF2 eutectic as the lubricating phase, exhibiting a low coefficient of friction in the range of room temperature to 650℃. However, with the development of high-end equipment technologies such as aerospace, there is an even more urgent need for wear-resistant lubricating materials used at even higher temperatures (800℃ or even 1000℃).

[0004] Therefore, inventing a coating material with a wide temperature range from room temperature to 1000℃ and good wear-reducing and wear-resistant effects is an urgent problem to be solved. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide an adaptive wide temperature range lubricating coating spray powder and its preparation method. The coating powder provided by the present invention has a wide temperature range and good friction reduction and wear resistance effects from room temperature to 1000℃.

[0006] This invention provides a spray powder for adaptive wide-temperature-range lubrication coatings, comprising, by weight percentage:

[0007] 20%~40% Cr2O3 (BaF2·CaF2);

[0008] 3%~8% Cu;

[0009] 3%~15% AgMo;

[0010] The margin is MCrAlYX;

[0011] In the MCrAlYX, M is Co and / or Ni, and X is at least one of Ta, Hf, and Si.

[0012] Preferably, the Cr2O3 (BaF2·CaF2) is a spherical powder;

[0013] Preferably, the Cr2O3 (BaF2·CaF2) is a spherical powder with a core-shell structure;

[0014] Preferably, the Cr2O3 (BaF2·CaF2) is a coated fine powder with Cr2O3 as the shell and BaF2·CaF2 eutectic as the core;

[0015] Preferably, the particle size of the Cr2O3 (BaF2·CaF2) is 1~3μm;

[0016] Preferably, the BaF2·CaF2 eutectic accounts for 20%~40% of the mass percentage of Cr2O3 (BaF2·CaF2).

[0017] Preferably, the AgMo is a silver-plated, spherical particle;

[0018] The AgMo has a particle size of 2μm to 5μm.

[0019] Preferably, the Cu is a spherical fine powder with a particle size of 1μm to 3μm.

[0020] Preferably, the particle size of the MCrAlYX is 3~5μm.

[0021] Preferably, by mass content, the MCrAlYX comprises: 15%~30% Cr, 5%~15% Al, 0.3%~1.5% Y, 0.3%~4.5% X, with the balance being M.

[0022] The present invention also provides a method for preparing the above-mentioned spray powder, comprising the following steps:

[0023] MCrAlYX powder, Cr2O3 (BaF2·CaF2) powder, Cu powder and AgMo powder were ball-milled in a high-energy ball mill in a certain proportion to obtain a mixed powder.

[0024] The mixed powder is mixed with a solvent to obtain a slurry;

[0025] The slurry is granulated and then calcined to obtain a spray powder.

[0026] Preferably, Cr2O3 (BaF2·CaF2) powder is prepared by the sol-gel method;

[0027] Preferably, the preparation method of the Cr2O3 (BaF2·CaF2) powder includes precursor solution preparation, oil phase solution preparation, and Cr2O3 (BaF2·CaF2) powder sintering.

[0028] Preferably, the preparation method of the Cr2O3 (BaF2·CaF2) powder includes the following steps:

[0029] 1) Prepare an aqueous solution of chromium nitrate in polyvinyl alcohol;

[0030] Prepare a mixed aqueous solution of hexamethylenetetramine and urea;

[0031] The pH was adjusted by mixing an aqueous solution of chromium nitrate in polyvinyl alcohol with a mixed aqueous solution of hexamethylenetetramine and urea to obtain a Cr2O3 precursor solution.

[0032] 2) Mix the BaF2·CaF2 eutectic with the Cr2O3 precursor solution to obtain a Cr2O3 (BaF2·CaF2) sol suspension;

[0033] 3) The Cr2O3 (BaF2·CaF2) sol suspension was placed in an oil phase solution and mixed and stirred to obtain Cr2O3 (BaF2·CaF2) sol droplets;

[0034] The oil phase solution includes trichloroethanol, isooctyl alcohol, and a surfactant;

[0035] 4) The Cr2O3 (BaF2·CaF2) sol solution was aged dropwise to obtain gel spheres;

[0036] 5) The gel spheres were calcined to obtain Cr2O3 (BaF2·CaF2) powder.

[0037] Preferably, the Cr in the polyvinyl alcohol aqueous solution of chromium nitrate is... 3+ The concentration is 0.2~0.5 mol / L;

[0038] In the mixed aqueous solution of hexamethylenetetramine and urea, the concentration of hexamethylenetetramine is 1~3 mol / L and the concentration of urea is 0.8~1.5 mol / L.

[0039] The volume ratio of the polyvinyl alcohol aqueous solution of chromium nitrate to the mixed aqueous solution of hexamethylenetetramine and urea is 1:1 to 1:1.5.

[0040] The pH is adjusted to 8-9;

[0041] In the oil phase solution, the volume ratio of trichloroethanol to isooctanol is 7:2 to 7:4, and the amount of surfactant added is 2% to 5%.

[0042] The mixing and stirring speed is 850~900 r / min;

[0043] The aging temperature is 100~120℃, and the time is 36~50h;

[0044] The calcination temperature is 600~800℃, and the time is 3~8h.

[0045] Preferably, the AgMo powder is prepared by chemical plating.

[0046] Preferably, the method for preparing AgMo powder includes the following steps:

[0047] a) Molybdenum powder was sensitized in a sensitizing solution and then activated in an activation solution to obtain the treated molybdenum powder;

[0048] b) After mixing the treated molybdenum powder with the reducing solution, silver ammonia solution is added to react and AgMo metal powder is obtained.

[0049] Preferably, the particle size of the molybdenum powder is 1~3μm;

[0050] The sensitizing solution comprises 10-20 g / L SnCl2·2H2O and 55-80 ml / L HCl;

[0051] The sensitization time is 5-8 minutes;

[0052] The activation solution comprises 0.2~0.5 g / L PdCl2 and 15~25 ml / L HCl;

[0053] The activation time is 5-8 minutes;

[0054] During the activation process, the amount of molybdenum powder added to the activation solution is 40~60 g / L;

[0055] The reducing solution comprises 10-15 g / L glucose and 100-115 g / L tartaric acid;

[0056] The silver ammonia solution is a transparent solution obtained by adding 30-35 mL / L NaOH aqueous solution to 0.05-0.15 mol / L AgNO3 aqueous solution to form AgOH precipitate, followed by adding ammonia.

[0057] The reaction time is 40-60 minutes;

[0058] The reaction process includes washing and drying, wherein the drying is performed under vacuum at 40°C and then dried at 50-60°C for 45-60 minutes.

[0059] Preferably, the calcination temperature is 800℃~900℃ and the time is 2~4h.

[0060] The present invention also provides a lubricating and wear-resistant coating, which is prepared from the above-mentioned sprayed powder.

[0061] Compared with existing technologies, this invention provides an adaptive wide-temperature-range lubricating coating spray powder, comprising, by mass percentage: 20%~40% Cr2O3 (BaF2·CaF2); 3%~8% Cu; 3%~15% AgMo; and the balance MCrAlYX; wherein, in MCrAlYX, M is Co and / or Ni, and X is at least one of Ta, Hf, and Si. The spray powder provided by this invention exhibits excellent and stable friction coefficients from room temperature to 1000℃, with friction coefficients all below 0.2. Coatings prepared from this spray powder are suitable for surface lubrication and wear-resistant coatings for sealing components of aero-engines. Attached Figure Description

[0062] Figure 1 The friction coefficient curve of the coating at 1000°C was prepared by spraying powder to prepare an adaptive wide temperature range lubricating coating in Example 2 of the present invention.

[0063] Figure 2 The three-dimensional image of the wear marks on the coating surface after a friction test at 1000℃ is shown in Example 2 of the present invention, which is prepared by spraying powder to form an adaptive wide temperature range lubricating coating. Detailed Implementation

[0064] This invention provides a spray powder for adaptive wide-temperature-range lubrication coatings, comprising, by weight percentage:

[0065] 20%~40% Cr2O3 (BaF2·CaF2);

[0066] 3%~8% Cu;

[0067] 3%~15% AgMo;

[0068] The margin is MCrAlYX;

[0069] In the MCrAlYX, M is Co and / or Ni, and X is at least one of Ta, Hf, and Si.

[0070] The spray powder provided by the present invention comprises 20% to 40% Cr2O3 (BaF2·CaF2) by weight percentage, which can be 20%, 22%, 25%, 27%, 30%, 32%, 35%, 37%, 40%, or any value between 20% and 40%.

[0071] In this invention, the hard wear-resistant phase Cr2O3 (BaF2·CaF2) coated powder with lubricating effect can reduce the ablation of the lubricating phase BaF2·CaF2 during the spraying process, improve the uniformity of the lubricating phase in the coating, form a lubricating film, and improve the high temperature stability and friction and wear performance of the coating.

[0072] In this invention, the Cr2O3 (BaF2·CaF2) is a spherical powder. Preferably, the Cr2O3 (BaF2·CaF2) is a spherical powder with a core-shell structure. More preferably, the Cr2O3 (BaF2·CaF2) is a coated fine powder with Cr2O3 as the shell and BaF2·CaF2 eutectic as the core;

[0073] In this invention, the particle size of Cr2O3 (BaF2·CaF2) is 1~3μm, which can be 1, 2, 3, or any value between 1 and 3μm.

[0074] In this invention, the mass percentage of the BaF2·CaF2 eutectic in Cr2O3 (BaF2·CaF2) is 20% to 40%, and can be any value between 20%, 22%, 25%, 27%, 30%, 32%, 35%, 37%, 40%, or 20% to 40%.

[0075] The spray powder provided by the present invention, by weight percentage, further includes 3% to 8% Cu, which can be any value between 3%, 4%, 5%, 6%, 7%, 8%, or 3% to 8%. The particle size of the Cu is 1 to 3 μm, which can be any value between 1, 2, 3, or 1 to 3 μm. Preferably, the Cu is in the form of spherical particles.

[0076] The spray powder provided by the present invention further includes 3% to 15% AgMo by weight percentage, which can be any value between 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, or 3% to 15%.

[0077] In this invention, AgMo is a silver-plated, spherical particle; the particle size of AgMo is 2μm to 5μm, and can be any value between 2, 3, 4, 5, or 2μm to 5μm.

[0078] The spray powder provided by the present invention, by weight percentage, further includes the balance MCrAlYX; wherein, in MCrAlYX, M is Co and / or Ni, and X is at least one of Ta, Hf, and Si.

[0079] In this invention, the copper powder has a particle size of 1μm to 3μm, which can be 1, 2, 3, or any value between 1 and 3μm.

[0080] In this invention, the particle size of MCrAlYX is 3~5μm, which can be 3, 4, 5, or any value between 3 and 5μm.

[0081] Based on mass content, the MCrAlYX comprises: 15%~30% Cr, 5%~15% Al, 0.3%~1.5% Y, 0.3%~4.5% X, with the balance being M.

[0082] The MCrAlYX contains 15% to 30% Cr, which can be 15%, 17%, 20%, 22%, 25%, 27%, 30%, or any value between 15% and 30%.

[0083] The MCrAlYX also includes 5% to 15% Al, which can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any value between 5% and 15%.

[0084] The MCrAlYX also includes 0.3% to 1.5% Y, which can be 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, or any value between 0.3% and 1.5%.

[0085] The MCrAlYX also includes 0.3% to 4.5% X, which can be 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or any value between 0.3% and 4.5%.

[0086] The MCrAlYX also includes a margin M.

[0087] In this invention, the four components are uniformly distributed in the sprayed powder.

[0088] In the spray powder provided by this invention, MCrAlYX serves as a binder phase material, which not only improves the compatibility of the coating with the high-temperature alloy substrate material but also possesses high-temperature oxidation resistance. Furthermore, the NiO and Al2O3 generated at high temperatures are also high-performance high-temperature solid lubricants, which help reduce the coefficient of friction of the coating at high temperatures. The addition of Cu increases the toughness of the material, while the addition of AgMo improves the strength of the coating material and provides lubrication at low temperatures. Cr2O3 in Cr2O3 (BaF2·CaF2) acts as a hard, wear-resistant phase with lubricating properties, improving the wear resistance of the coating and also playing a certain role in reducing friction. BaF2·CaF2 enhances the lubrication and friction-reducing effect of the coating in the mid-temperature range.

[0089] The wide-temperature-range self-lubricating wear-resistant coating spray powder material provided by this invention can spontaneously achieve lubrication and friction reduction effects through its own or reaction-generated lubricants at different temperature ranges, exhibiting temperature-adaptive lubrication. Below 600℃, Cu and Ag form a lubricating film, producing a lubricating effect; at 600~700℃, BaF2·CaF2 exhibits excellent lubrication and friction reduction effects; above 700℃, under high-temperature friction and load, metallic Cu and AgMo can undergo a tribochemical reaction on the friction surface, generating AgMo with high-temperature lubrication properties in situ, aided by ambient heat and frictional heat. x O y CuMo x O y The results show that the coatings prepared by the spray powder material of the present invention have excellent and stable coefficients of friction from room temperature to 1000°C, and the coefficients of friction are all below 0.2.

[0090] The present invention also provides a method for preparing the above-mentioned spray powder, comprising the following steps:

[0091] MCrAlYX powder, Cr2O3 (BaF2·CaF2) powder, Cu powder and AgMo powder were ball-milled in a high-energy ball mill in a certain proportion to obtain a mixed powder.

[0092] The mixed powder is mixed with a solvent to obtain a slurry;

[0093] The slurry is granulated and then calcined to obtain a spray powder.

[0094] Specifically, the present invention first ball-mills MCrAlYX powder, Cr2O3 (BaF2·CaF2) powder, Cu powder and AgMo powder in a high-energy ball mill according to a certain ratio to obtain a mixed powder.

[0095] In this invention, Cr2O3 (BaF2·CaF2) powder is prepared using the sol-gel method;

[0096] Preferably, the preparation method of the Cr2O3 (BaF2·CaF2) powder includes precursor solution preparation, oil phase solution preparation, and Cr2O3 (BaF2·CaF2) powder sintering.

[0097] In some specific embodiments of the present invention, the preparation method of the Cr2O3(BaF2·CaF2) powder includes the following steps:

[0098] 1) Prepare an aqueous solution of chromium nitrate in polyvinyl alcohol;

[0099] Prepare a mixed aqueous solution of hexamethylenetetramine and urea;

[0100] The pH was adjusted by mixing an aqueous solution of chromium nitrate in polyvinyl alcohol with a mixed aqueous solution of hexamethylenetetramine and urea to obtain a Cr2O3 precursor solution.

[0101] 2) Mix the BaF2·CaF2 eutectic with the Cr2O3 precursor solution to obtain a Cr2O3 (BaF2·CaF2) sol suspension;

[0102] 3) The Cr2O3 (BaF2·CaF2) sol suspension was placed in an oil phase solution and mixed and stirred to obtain Cr2O3 (BaF2·CaF2) sol droplets;

[0103] The oil phase solution includes trichloroethanol, isooctyl alcohol, and a surfactant;

[0104] 4) The Cr2O3 (BaF2·CaF2) sol solution was aged dropwise to obtain gel spheres;

[0105] 5) The gel spheres were calcined to obtain Cr2O3 (BaF2·CaF2) powder.

[0106] Specifically, the present invention first prepares a solution.

[0107] The polyvinyl alcohol aqueous solution of chromium nitrate is prepared according to the following method:

[0108] First, chromium nitrate Cr(NO3)3·9H2O is added to a polyvinyl alcohol aqueous solution, stirred in a water bath at 50~80℃ for 30~50 min, and then cooled to room temperature to obtain a polyvinyl alcohol aqueous solution of chromium nitrate.

[0109] The Cr in the polyvinyl alcohol aqueous solution of chromium nitrate 3+ The concentration is 0.2~0.5 mol / L, and can be any value between 0.2, 0.3, 0.4, 0.5, or 0.2~0.5 mol / L.

[0110] The aqueous solution of hexamethylenetetramine and urea was prepared according to the following method:

[0111] Add hexamethylenetetramine and urea to deionized water and mix and stir to obtain a mixed aqueous solution of hexamethylenetetramine and urea.

[0112] In the mixed aqueous solution of hexamethylenetetramine and urea, the concentration of hexamethylenetetramine is 1~3 mol / L, which can be any value between 1, 1.5, 2, 2.5, 3, or 1~3 mol / L, and the concentration of urea is 0.8~1.5 mol / L, which can be any value between 0.8, 1, 1.2, 1.4, 1.5, or 0.8~1.5 mol / L.

[0113] The volume ratio of the polyvinyl alcohol aqueous solution of chromium nitrate to the mixed aqueous solution of hexamethylenetetramine and urea is 1:1 to 1:1.5, and can be any ratio between 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, or 1:1 to 1:1.5.

[0114] The pH is adjusted to 8-9 by mixing an aqueous solution of chromium nitrate in polyvinyl alcohol with a mixed aqueous solution of hexamethylenetetramine and urea. The pH can be 8, 8.2, 8.4, 8.5, 8.6, 8.8, 9, or any value between 8 and 9. In this invention, nitric acid is preferably used to adjust the pH.

[0115] The preparation of the Cr2O3 precursor solution was carried out by mixing and stirring in an ice bath.

[0116] Next, the BaF2·CaF2 eutectic was mixed with the Cr2O3 precursor solution to obtain a Cr2O3 (BaF2·CaF2) sol suspension. Specifically, the BaF2·CaF2 eutectic was added to the Cr2O3 precursor solution and stirred continuously to ensure that the BaF2·CaF2 eutectic was uniformly dispersed in the Cr2O3 precursor solution. The particle size of the BaF2·CaF2 eutectic was 100~200 nm.

[0117] Then, the Cr2O3 (BaF2·CaF2) sol suspension was placed in an oil phase solution and mixed and stirred to obtain Cr2O3 (BaF2·CaF2) sol droplets.

[0118] Specifically, the Cr2O3 (BaF2·CaF2) sol suspension is slowly poured into the oil phase solution and stirred at a speed of 850~900 r / min to form Cr2O3 (BaF2·CaF2) sol droplets.

[0119] The oil phase solution comprises trichloroethanol, isooctanol, and a surfactant. In the oil phase solution, the volume ratio of trichloroethanol to isooctanol is 7:2 to 7:4, which can be 7:2, 7:3, 7:4, or any value between 7:2 and 7:4. The amount of surfactant added is 2% to 5%, which can be 2%, 3%, 4%, 5%, or any value between 2% and 5%. In this invention, the surfactant is selected from at least one of potassium stearate and sodium dodecylbenzenesulfonate.

[0120] After obtaining Cr2O3(BaF2·CaF2) sol droplets, the Cr2O3(BaF2·CaF2) sol droplets are aged to obtain gel spheres. The aging temperature is 100~120℃, which can be 100, 105, 110, 115, 120, or any value between 100~120℃, and the time is 36~50h, which can be 36, 40, 45, 50, or any value between 36~50h.

[0121] Then, the gel spheres are washed, dried, and calcined to obtain Cr2O3 (BaF2·CaF2) powder. The calcination temperature is 600~800℃, which can be 600, 650, 700, 750, 800, or any value between 600 and 800℃, and the time is 3~8h, which can be 3, 4, 5, 6, 7, 8, or any value between 3 and 8h.

[0122] The AgMo powder was prepared by chemical plating.

[0123] Preferably, the method for preparing AgMo powder includes the following steps:

[0124] a) Molybdenum powder was sensitized in a sensitizing solution and then activated in an activation solution to obtain the treated molybdenum powder;

[0125] b) After mixing the treated molybdenum powder with the reducing solution, silver ammonia solution is added to react and AgMo metal powder is obtained.

[0126] Specifically, the present invention first sensitizes molybdenum powder in a sensitizing solution.

[0127] The molybdenum powder has a particle size of 1~3μm, which can be 1, 2, 3, or any value between 1~3μm. The molybdenum powder is spherical.

[0128] The sensitizing solution comprises 10-20 g / L SnCl2·2H2O and 55-80 ml / L HCl, wherein the concentration of SnCl2·2H2O can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or any value between 10 and 20 g / L, and the concentration of HCl can be 55, 60, 65, 70, 75, 80, or any value between 55 and 80 ml / L.

[0129] The sensitization time is 5-8 minutes, and can be any value between 5, 6, 7, 8 minutes, or 5-8 minutes. After sensitization, wash with distilled water.

[0130] Then, the molybdenum powder is activated in an activation solution comprising 0.2-0.5 g / L PdCl2 and 15-25 ml / L HCl, wherein the concentration of HCl can be 15, 18, 20, 22, 25, or any value between 15 and 25 ml / L; wherein the concentration of PdCl2 can be 0.2, 0.3, 0.4, 0.5, or any value between 0.2 and 0.5 g / L.

[0131] The activation time is 5-8 minutes, and can be any value between 5, 6, 7, 8 minutes, or 5-8 minutes. After activation, wash with distilled water.

[0132] During activation, the amount of molybdenum powder added to the activation solution is 40~60 g / L, which can be any value between 40, 45, 50, 55, 60, or 40~60 g / L.

[0133] After activation, the treated molybdenum powder is obtained. Then, the treated molybdenum powder is mixed with the reducing solution and silver ammonia solution is added to react and AgMo metal powder is obtained.

[0134] The reducing solution comprises 10-15 g / L glucose and 100-115 g / L tartaric acid. The concentration of glucose can be 10, 11, 12, 13, 14, 15, or any value between 10 and 15 g / L, and the concentration of tartaric acid can be 100, 102, 104, 105, 106, 108, 110, 115, or any value between 100 and 115 g / L.

[0135] The method for preparing the reducing solution includes the following steps:

[0136] Glucose and tartaric acid are boiled in distilled water and then cooled. Ethanol is then added to obtain a reducing solution.

[0137] The boiling time is 8 to 12 minutes, which can be any value between 8, 9, 10, 11, 12 minutes, or 8 to 12 minutes. The amount of ethanol added is 150 to 300 ml, which can be any value between 150, 200, 250, 300 ml, or 150 to 300 ml.

[0138] The silver ammonia solution is a transparent solution obtained by adding 30-35 mL / L NaOH aqueous solution to 0.05-0.15 mol / L AgNO3 aqueous solution dropwise to form AgOH precipitate, followed by the addition of ammonia.

[0139] Molybdenum powder was added to a reducing solution, and silver ammonia solution was slowly added under magnetic stirring. After reacting at room temperature, the solution was filtered to remove the plating solution and obtain the powder.

[0140] The reaction time is 40-60 min, which can be any value between 40, 50, 60, or 40-60 min; in this invention, room temperature is defined as 25±5℃.

[0141] The reaction process includes washing and drying. Washing involves washing the obtained powder several times with distilled water followed by filtration. Drying involves drying under vacuum at 40°C, followed by drying at 50-60°C for 45-60 minutes.

[0142] In this invention, both the MCrAlYX powder and Cu powder are commercially available powders.

[0143] After the raw materials are prepared, MCrAlYX powder, Cr2O3 (BaF2·CaF2) powder, Cu powder, and AgMo powder are ball-milled in a high-energy ball mill according to a certain ratio to obtain a mixed powder. The ball milling time is 2-3 hours.

[0144] Then, the mixed powder is mixed with a solvent to obtain a slurry. The solid content of the slurry is 35% to 45%, and can be any value between 35%, 37%, 40%, 42%, 45%, or 35% to 45%. The solvent for preparing the slurry is water or ethanol, and the binder for the slurry is polyvinyl alcohol (PVA).

[0145] Next, the slurry is granulated. In this invention, centrifugal spray granulation is preferably used, and the slurry is granulated using a centrifugal spray drying device, wherein the rotary table speed is 70000 r / min~85000 r / min, the inlet temperature is 200℃~300℃, and the outlet temperature is 120℃~180℃.

[0146] Finally, calcination is performed to obtain the sprayable powder. The calcination atmosphere is nitrogen, the calcination temperature is 800℃~900℃ (can be 800, 820, 840, 850, 860, 880, 900, or any value between 800℃ and 900℃), and the time is 2~4 hours (can be 2, 3, 4, or any value between 2 and 4 hours).

[0147] After sieving, the final spray powder has a particle size range of 25~125μm, with the powder mass percentage of particles ≤25μm not exceeding 10%, the powder mass percentage of particles larger than 125μm not exceeding 10%, and the powder mass percentage of particles in the range of 25~125μm being ≥80%.

[0148] The preparation method provided by the present invention can not only ensure the uniformity and particle size of the powder material units, but also ensure the compositional uniformity of the final composite powder, and ensure the uniformity of the structure and function of the powder material when forming the coating.

[0149] This invention also provides a lubricating and wear-resistant coating, prepared from the aforementioned sprayed powder. The invention does not impose any particular limitations on the preparation method of the lubricating and wear-resistant coating; it can be plasma spraying or supersonic spraying. The resulting lubricating and wear-resistant coating is suitable for surface lubrication and wear-resistant coating of sealing components in aero-engines.

[0150] The sprayable powder provided by this invention exhibits excellent and stable friction coefficients from room temperature to 1000°C, with friction coefficients consistently below 0.2. The coatings prepared from this sprayable powder are suitable for surface lubrication and wear-resistant coatings on sealing components of aero-engines.

[0151] To further understand the present invention, the following description, in conjunction with embodiments, illustrates the spray powder for adaptive wide-temperature-range lubrication coatings and its preparation method provided by the present invention. The scope of protection of the present invention is not limited by the following embodiments.

[0152] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0153] Unless otherwise specified, all experimental materials used in the following examples were purchased from conventional reagent stores.

[0154] Example 1

[0155] This invention provides a spray powder for an adaptive wide-temperature-range lubricating coating with the composition of Ni23Co20Cr8.5Al0.6Y4Ta + Cr2O3(BaF2·CaF2) + Cu + AgMo, wherein the mass percentage of Cr2O3(BaF2·CaF2) is 20%, the mass percentage of Cu is 3%, the mass percentage of AgMo is 3%, and the balance is Ni23Co20Cr8.5Al0.6Y4Ta.

[0156] The specific steps of the preparation method for spray powder used in adaptive wide-temperature-range lubricating coatings are as follows:

[0157] I. Preparation of Cr2O3 (BaF2·CaF2) coated powder:

[0158] 1) Preparation of Cr2O3 (BaF2·CaF2) precursor solution: First, chromium nitrate Cr(NO3)3·9H2O was added to a polyvinyl alcohol aqueous solution, stirred in a 50℃ water bath for 50 min, and then cooled to room temperature to obtain Cr2O3 (BaF2·CaF2) precursor solution. 3+ Solution A was prepared with a concentration of 0.2 mol / L. Then, 1 mol / L hexamethylenetetramine and 0.8 mol / L urea were added to deionized water and stirred until homogeneous to obtain solution B. Solution B was added to solution A at a volume ratio of 1:1, and then nitric acid was added to the mixture to adjust the pH to 8. The mixture was stirred in an ice-water bath for 20 min to obtain a Cr₂O₃ precursor solution. Subsequently, the Cr₂O₃ precursor solution was prepared. 3+ BaF2·CaF2 eutectic powder with a mass percentage of 36% and a particle size of 100 nm was added to the precursor solution and stirred continuously to make the BaF2·CaF2 eutectic powder uniformly dispersed in the Cr2O3 precursor solution, thus obtaining a Cr2O3 (BaF2·CaF2) sol suspension.

[0159] 2) Preparation of oil phase solution: Prepare an oil phase solution of trichloroethanol and isooctanol in a volume ratio of 7:2, and add 2% of potassium stearate surfactant and stir evenly. Slowly pour the prepared Cr2O3 (BaF2·CaF2) sol suspension into the oil phase solution and stir at 850 r / min to form Cr2O3 (BaF2·CaF2) sol droplets.

[0160] 3) Sintering of Cr2O3 (BaF2·CaF2) powder: Cr2O3 (BaF2·CaF2) sol droplets were aged at a constant temperature of 100℃ for 36 hours to form gel spheres. After cleaning and drying, the spheres were calcined at 600℃ for 8 hours to prepare Cr2O3 (BaF2·CaF2) coated powder with a particle size of 1μm. BaF2·CaF2 accounted for 20% of the mass percentage of the Cr2O3 (BaF2·CaF2) powder.

[0161] II. Preparation of AgMo-coated powder:

[0162] 1) Commercially available 1μm spherical molybdenum powder was sensitized and activated. The sensitization solution consisted of 10g / L SnCl2·2H2O and 55ml / L HCl; the activation solution consisted of 0.25g / L PdCl2 and 20ml / L HCl. Sensitization was performed in the sensitization solution for 5min, followed by activation in the activation solution for 5min. The amount of molybdenum powder added during activation was 40g / L. After activation and sensitization, the powder was washed with distilled water before use.

[0163] 2) Prepare the reducing solution, which consists of glucose and tartaric acid, with the amount of glucose added being 10 g / L and the amount of tartaric acid added being 100 g / L. After boiling in distilled water for 8 minutes, cool and then add 150 ml of ethanol.

[0164] 3) Prepare silver ammonia solution. Prepare a 0.05 mol / L AgNO3 aqueous solution and a 30 mL / L NaOH aqueous solution. Slowly add the NaOH solution to the AgNO3 solution to form AgOH precipitate. Slowly add ammonia solution while stirring until the AgOH precipitate just dissolves into a clear liquid.

[0165] 4) Add molybdenum powder to the reducing solution, and slowly add silver ammonia complex solution under magnetic stirring. After reacting at room temperature for 40 minutes, filter out the plating solution, wash the obtained powder several times with distilled water, filter it, and dry it under vacuum at 40°C to obtain silver-molybdenum metal powder.

[0166] 5) The obtained silver-molybdenum metal powder was dried in a vacuum oven at 50°C for 45 min to obtain 2μm silver-molybdenum metal powder.

[0167] III. Preparation of Composite Powders by Spray Granulation

[0168] Commercially available Ni23Co20Cr8.5Al0.6Y4Ta powder with a particle size of 3μm, Cr2O3 (BaF2·CaF2) powder with a particle size of 1μm, spherical Cu powder with a particle size of 1μm and AgMo with a particle size of 2μm were ball-milled in a high-energy ball mill for 2 hours to obtain a uniformly mixed powder. A slurry with a solid content of 35% was prepared by using water and polyvinyl alcohol.

[0169] The slurry is granulated using a centrifugal spray drying equipment, wherein the rotary table speed is 70,000 r / min, the inlet temperature is 200℃, and the outlet temperature is 120℃.

[0170] The composite powder obtained by granulation was calcined under a nitrogen atmosphere at a temperature of 800°C for 2 hours. After natural cooling, an adaptive wide-temperature-range lubricating coating spray powder NiCoCrAlYTa+Cr2O3(BaF2·CaF2)+Cu+AgMo was obtained with a particle size range of 25~125μm.

[0171] Example 2

[0172] This invention provides a spray powder for an adaptive wide-temperature-range lubricating coating, which is composed of Ni12Co17Cr12Al0.3Y0.6Hf + Cr2O3(BaF2·CaF2) + Cu + AgMo, wherein the mass percentage of Cr2O3(BaF2·CaF2) is 40%, the mass percentage of Cu is 8%, the mass percentage of AgMo is 15%, and the balance is Ni12Co17Cr12Al0.3Y0.6Hf.

[0173] The specific steps of the preparation method for spray powder used in adaptive wide-temperature-range lubricating coatings are as follows:

[0174] I. Preparation of Cr2O3 (BaF2·CaF2) coated powder:

[0175] 1) Preparation of Cr2O3 (BaF2·CaF2) precursor solution: First, chromium nitrate Cr(NO3)3·9H2O was added to a polyvinyl alcohol aqueous solution, stirred in an 80℃ water bath for 30 min, and then cooled to room temperature to obtain Cr2O3 (BaF2·CaF2) precursor solution. 3+ Solution A was prepared with a concentration of 0.5 mol / L. Then, 3 mol / L hexamethylenetetramine and 1.5 mol / L urea were added to deionized water and stirred until homogeneous to obtain solution B. Solution B was added to solution A at a volume ratio of 1:1.5, and then nitric acid was added to the mixture to adjust the pH to 9. The mixture was stirred in ice water for 30 minutes to obtain a Cr₂O₃ precursor solution. Subsequently, the Cr₂O₃ precursor solution was prepared. 3+ BaF2·CaF2 eutectic powder with a mass percentage of 90% and a particle size of 200 nm was added to the precursor solution and stirred continuously to make the BaF2·CaF2 eutectic powder uniformly dispersed in the Cr2O3 precursor solution, thus obtaining a Cr2O3 (BaF2·CaF2) sol suspension.

[0176] 2) Preparation of oil phase solution: Prepare an oil phase solution of trichloroethanol and isooctanol in a volume ratio of 7:4, and add 5% sodium dodecylbenzenesulfonate surfactant and stir evenly. Slowly pour the prepared Cr2O3 (BaF2·CaF2) sol suspension into the oil phase solution and stir at 900 r / min to form Cr2O3 (BaF2·CaF2) sol droplets.

[0177] 3) Sintering of Cr2O3 (BaF2·CaF2) powder: Cr2O3 (BaF2·CaF2) sol droplets were aged at a constant temperature of 120℃ for 50h to form gel spheres. After cleaning and drying, they were calcined at 800℃ for 3h to prepare Cr2O3 (BaF2·CaF2) coated powder with a particle size of 3μm, of which BaF2·CaF2 accounted for 40% of the mass percentage of Cr2O3 (BaF2·CaF2) powder.

[0178] II. Preparation of AgMo-coated powder:

[0179] 1) Commercially available 3μm spherical molybdenum powder was sensitized and activated. The sensitization solution consisted of 20g / L SnCl2·2H2O and 80ml / L HCl; the activation solution consisted of 0.5g / L PdCl2 and 20ml / L HCl. Sensitization was performed in the sensitization solution for 8min, followed by activation in the activation solution for 8min. The amount of molybdenum powder added during activation was 60g / L. After activation and sensitization, the powder was washed with distilled water before use.

[0180] 2) Prepare the reducing solution, which consists of glucose and tartaric acid, with the amount of glucose added being 15 g / L and the amount of tartaric acid added being 110 g / L. After boiling in distilled water for 12 minutes, cool and then add 300 ml of ethanol.

[0181] 3) Prepare silver ammonia solution. Prepare a 0.15 mol / L AgNO3 aqueous solution and a 35 mL / L NaOH aqueous solution. Slowly add the NaOH solution to the AgNO3 solution to form AgOH precipitate. Slowly add ammonia solution while stirring until the AgOH precipitate just dissolves and becomes a transparent liquid.

[0182] 4) Add molybdenum powder to the reducing solution, and slowly add silver ammonia complex solution under magnetic stirring. After reacting at room temperature for 60 minutes, filter out the plating solution, wash the obtained powder several times with distilled water, filter it, and dry it under vacuum at 40°C to obtain silver-molybdenum metal powder.

[0183] 5) The obtained silver-molybdenum metal powder was dried in a vacuum oven at 60°C for 60 min to obtain 5μm silver-molybdenum metal powder.

[0184] III. Preparation of Composite Powders by Spray Granulation

[0185] Commercially available Ni12Co17Cr12Al0.3Y0.6Hf powder with a particle size of 5μm, Cr2O3 (BaF2·CaF2) powder with a particle size of 3μm, spherical Cu powder with a particle size of 2μm and AgMo with a particle size of 5μm were ball-milled in a high-energy ball mill for 3 hours to obtain a uniformly mixed powder. A slurry with a solid content of 45% was prepared by using water and the binder polyvinyl alcohol.

[0186] The slurry is granulated using a centrifugal spray drying equipment, wherein the rotary table speed is 85000 r / min, the inlet temperature is 300℃, and the outlet temperature is 180℃.

[0187] The composite powder obtained by granulation was calcined under a nitrogen atmosphere at a temperature of 900°C for 4 hours. After natural cooling, an adaptive wide-temperature-range lubricating coating spray powder NiCoCrAlYHf+Cr2O3(BaF2·CaF2)+Cu+AgMo was obtained with a particle size range of 25~125μm.

[0188] Example 3

[0189] This invention provides a spray powder for an adaptive wide-temperature-range lubricating coating with the composition of Ni22Co17Cr12Al0.5Hf0.5Y0.4Si + Cr2O3(BaF2·CaF2) + Cu + AgMo, wherein the mass percentage of Cr2O3(BaF2·CaF2) is 30%, the mass percentage of Cu is 5%, the mass percentage of AgMo is 10%, and the balance is Ni22Co17Cr12Al0.5Hf0.5Y0.4Si.

[0190] The specific steps of a method for preparing an adaptive wide-temperature-range lubricating coating spray powder are as follows:

[0191] I. Preparation of Cr2O3 (BaF2·CaF2) coated powder:

[0192] 1) Preparation of Cr2O3 (BaF2·CaF2) precursor solution: First, chromium nitrate Cr(NO3)3·9H2O was added to a polyvinyl alcohol aqueous solution and stirred in a 70℃ water bath for 40 min. After cooling to room temperature, Cr2O3 (BaF2·CaF2) precursor solution was obtained. 3+ Solution A was prepared with a concentration of 0.35 mol / L. Then, 2 mol / L hexamethylenetetramine and 1.1 mol / L urea were added to deionized water and stirred until homogeneous to obtain solution B. Solution B was added to solution A at a volume ratio of 1:1.2, and then nitric acid was added to the mixture to adjust the pH to 8.5. The mixture was stirred in ice water for 25 min to obtain a Cr₂O₃ precursor solution. Subsequently, BaF₂·CaF₂ eutectic powder with a particle size of 150 nm was added according to the Cr... 3+ The mass percentage of 62% was added to the precursor solution and stirred continuously to make the BaF2·CaF2 eutectic powder uniformly dispersed in the Cr2O3 precursor solution, thus obtaining a Cr2O3 (BaF2·CaF2) sol suspension.

[0193] 2) Preparation of oil phase solution: Prepare an oil phase solution of trichloroethanol and isooctanol in a volume ratio of 7:3, and add 3.5% potassium stearate surfactant and stir evenly. Slowly pour the prepared Cr2O3 (BaF2·CaF2) sol suspension into the oil phase solution and stir at 880 r / min to form Cr2O3 (BaF2·CaF2) sol droplets;

[0194] 3) Sintering of Cr2O3 (BaF2·CaF2) powder: Cr2O3 (BaF2·CaF2) sol droplets were aged at a constant temperature of 110℃ for 45h to form gel spheres. After cleaning and drying, they were calcined at 700℃ for 5h to prepare Cr2O3 (BaF2·CaF2) coated powder with a particle size of 2μm, in which BaF2·CaF2 accounted for 30% of the mass percentage of Cr2O3 (BaF2·CaF2) powder.

[0195] II. Preparation of AgMo-coated powder:

[0196] 1) Commercially available 2μm spherical molybdenum powder was sensitized and activated. The sensitization solution consisted of 15g / L SnCl2·2H2O and 70ml / L HCl; the activation solution consisted of 0.4g / L PdCl2 and 20ml / L HCl. Sensitization was performed in the sensitization solution for 6min, followed by activation in the activation solution for 7min. The amount of molybdenum powder added during activation was 50g / L. After activation and sensitization, the powder was washed with distilled water before use.

[0197] 2) Prepare the reducing solution, which consists of glucose and tartaric acid, with the amount of glucose added being 12 g / L and the amount of tartaric acid added being 115 g / L. After boiling in distilled water for 10 minutes, cool and then add 230 ml of ethanol.

[0198] 3) Prepare silver ammonia solution. Prepare a 0.08 mol / L AgNO3 aqueous solution and a 32 mL / L NaOH aqueous solution. Slowly add the NaOH solution to the AgNO3 solution to form AgOH precipitate. Slowly add ammonia solution while stirring until the AgOH precipitate just dissolves and becomes a transparent liquid.

[0199] 4) Add molybdenum powder to the reducing solution, and slowly add silver ammonia complex solution under magnetic stirring. After reacting at room temperature for 50 minutes, filter out the plating solution, wash the obtained powder several times with distilled water, filter it, and dry it under vacuum at 40°C to obtain silver-molybdenum metal powder.

[0200] 5) The obtained silver-molybdenum metal powder was dried in a vacuum oven at 55°C for 50 min to obtain 4μm silver-molybdenum metal powder.

[0201] III. Preparation of Composite Powders by Spray Granulation

[0202] Commercially available Ni22Co17Cr12Al0.5Hf0.5Y0.4Si powder with a particle size of 4μm, Cr2O3 (BaF2·CaF2) powder with a particle size of 2μm, spherical Cu powder with a particle size of 3μm and AgMo with a particle size of 4μm were ball-milled in a high-energy ball mill for 2.5h to obtain a uniformly mixed powder. A slurry with a solid content of 40% was prepared with ethanol and 30wt% polyvinyl alcohol.

[0203] The slurry is granulated using a centrifugal spray drying equipment, wherein the rotary table speed is 78000 r / min, the inlet temperature is 250℃, and the outlet temperature is 150℃.

[0204] The composite powder obtained by granulation was calcined under a nitrogen atmosphere at a temperature of 850°C for 3 hours. After natural cooling, an adaptive wide-temperature-range lubricating coating spray powder Ni22Co17Cr12Al0.5Hf0.5Y0.4Si+Cr2O3(BaF2·CaF2)+Cu+AgMo was obtained with a particle size ranging from 25 to 125 μm.

[0205] Comparative Example

[0206] Commercially available Ni24.5Cr6Al0.4Y powder with a particle size of 15μm, commercially available spherical Cr2O3 powder with a particle size of 45μm, commercially available BaF2·CaF2 eutectic powder with a particle size of 45μm, and spherical Cu powder with a particle size of 45μm were ball-milled in a high-energy ball mill for 3 hours to obtain a uniformly mixed powder. A slurry with a solid content of 30% was then prepared with ethanol and 30wt% polyvinyl alcohol.

[0207] The slurry is granulated using a centrifugal spray drying equipment, wherein the rotary table speed is 82000 r / min, the inlet temperature is 280℃, and the outlet temperature is 160℃.

[0208] The composite powder obtained by granulation is calcined under a nitrogen atmosphere at a temperature of 900°C for 3.5 hours. After natural cooling, a wear-resistant and lubricating coating spray powder, Ni24.5Cr6Al0.4Y+Cr2O3+BaF2·CaF2+Cu composite powder, is obtained with a particle size ranging from 25 to 125 μm.

[0209] Test case

[0210] Wear-resistant coatings were prepared on the surface of high-temperature alloys using the same thermal spraying method on the powders obtained in the above embodiments and comparative examples. The coatings were then subjected to tribological tests at room temperature (RT), 500℃, 700℃, and 1000℃ under the same load and rotation speed. The friction coefficient was tested using the ball-and-disc method at a rotation speed of 500 r / min, a rotation radius of 10 mm, a load of 10 N, and a test time of 30 min. The friction coefficient was calculated based on the following formula:

[0211]

[0212] Where μ represents the coefficient of friction, F represents the frictional force, and N represents the normal force perpendicular to the contact surface. The frictional force F is measured in real time by a piezoelectric sensor, while the normal force N is applied by a precisely controlled loading system.

[0213] The wear rate is the ratio of the wear volume in the wear track area of ​​the specimen to the product of the test load and the total sliding distance, as shown in the following formula:

[0214]

[0215] Where ω is the wear rate, in mm. 3 / (N·m), where V is the wear volume in mm. 3 P represents the applied load pressure in N; S represents the total sliding length in mm. A white light interferometer was used to collect the cross-sectional profile of the wear track area around the wear track circumference. The product of the cross-sectional area and the circumference of the wear track centerline was taken as the wear volume. The friction coefficient and wear rate of coatings made from different powder materials at different temperatures were compared. The specific results are shown in Tables 1 and 2.

[0216] Table 1. Measured results of friction coefficients of powders after coating at different temperatures.

[0217]

[0218] Table 2. Measured wear rate of powder coatings prepared at different temperatures (×10) -6 mm 3 / (N·m))

[0219]

[0220] As shown in Tables 1 and 2, the spray powder provided by this invention exhibits excellent and stable friction coefficients from room temperature to 1000℃, with friction coefficients consistently below 0.2. The powder material prepared by this invention can protect the lubricating phase from ablation during the spraying process and can adaptively form new lubricating phases according to temperature changes. Therefore, compared with the comparative example, the friction coefficient and wear rate in the embodiments of this invention are very low, achieving the effects of friction reduction and wear resistance. The coating prepared using the spray powder of this invention is suitable for surface lubrication and wear-resistant coatings for sealing components of aero-engines.

[0221] Among them, by Figure 1 and Figure 2 The results show that the coating prepared by the powder of this invention has a friction coefficient of less than 0.2 at 1000℃, and the friction coefficient is stable without fluctuation. The coating has shallow scratches and less wear.

[0222] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A spray powder for adaptive wide-temperature-range lubricating coatings, characterized in that, In terms of mass percentage, it includes: 20%~40% Cr2O3 (BaF2·CaF2); 3%~8% Cu; 3%~15% AgMo; The margin is MCrAlYX; In the MCrAlYX, M is Co and / or Ni, and X is at least one of Ta, Hf, and Si.

2. The sprayable powder according to claim 1, characterized in that, The Cr2O3 (BaF2·CaF2) is a spherical powder; Preferably, the Cr2O3 (BaF2·CaF2) is a spherical powder with a core-shell structure; Preferably, the Cr2O3 (BaF2·CaF2) is a coated fine powder with Cr2O3 as the shell and BaF2·CaF2 eutectic as the core; Preferably, the particle size of the Cr2O3 (BaF2·CaF2) is 1~3μm; Preferably, the BaF2·CaF2 eutectic accounts for 20%~40% of the mass percentage of Cr2O3 (BaF2·CaF2).

3. The sprayable powder according to claim 1, characterized in that, The AgMo is a silver-plated, round particle with a molybdenum surface. The AgMo has a particle size of 2μm to 5μm; The Cu is a spherical fine powder with a particle size of 1μm to 3μm.

4. The sprayable powder according to claim 1, characterized in that, The particle size of the MCrAlYX is 3~5μm; Preferably, by mass content, the MCrAlYX comprises: 15%~30% Cr, 5%~15% Al, 0.3%~1.5% Y, 0.3%~4.5% X, with the balance being M.

5. A method for preparing the spray powder as described in any one of claims 1 to 4, characterized in that, Includes the following steps: MCrAlYX powder, Cr2O3 (BaF2·CaF2) powder, Cu powder and AgMo powder were ball-milled in a high-energy ball mill in a certain proportion to obtain a mixed powder. The mixed powder is mixed with a solvent to obtain a slurry; The slurry is granulated and then calcined to obtain a spray powder.

6. The preparation method according to claim 5, characterized in that, Cr2O3 (BaF2·CaF2) powder was prepared by sol-gel method; Preferably, the preparation method of the Cr2O3 (BaF2·CaF2) powder includes precursor solution preparation, oil phase solution preparation, and Cr2O3 (BaF2·CaF2) powder sintering; Preferably, the preparation method of the Cr2O3 (BaF2·CaF2) powder includes the following steps: 1) Prepare an aqueous solution of chromium nitrate in polyvinyl alcohol; Prepare a mixed aqueous solution of hexamethylenetetramine and urea; The pH was adjusted by mixing an aqueous solution of chromium nitrate in polyvinyl alcohol with a mixed aqueous solution of hexamethylenetetramine and urea to obtain a Cr2O3 precursor solution. 2) Mix the BaF2·CaF2 eutectic with the Cr2O3 precursor solution to obtain a Cr2O3 (BaF2·CaF2) sol suspension; 3) The Cr2O3 (BaF2·CaF2) sol suspension was placed in an oil phase solution and mixed and stirred to obtain Cr2O3 (BaF2·CaF2) sol droplets; The oil phase solution includes trichloroethanol, isooctyl alcohol, and a surfactant; 4) The Cr2O3 (BaF2·CaF2) sol solution was aged dropwise to obtain gel spheres; 5) The gel spheres were calcined to obtain Cr2O3 (BaF2·CaF2) powder.

7. The preparation method according to claim 5, characterized in that, The Cr in the polyvinyl alcohol aqueous solution of chromium nitrate 3+ The concentration is 0.2~0.5 mol / L; In the mixed aqueous solution of hexamethylenetetramine and urea, the concentration of hexamethylenetetramine is 1~3 mol / L and the concentration of urea is 0.8~1.5 mol / L. The volume ratio of the polyvinyl alcohol aqueous solution of chromium nitrate to the mixed aqueous solution of hexamethylenetetramine and urea is 1:1 to 1:1.

5. The pH is adjusted to 8-9; In the oil phase solution, the volume ratio of trichloroethanol to isooctyl alcohol is 7:2 to 7:4, and the amount of surfactant added is 2% to 5%. The mixing and stirring speed is 850~900 r / min; The aging temperature is 100~120℃, and the time is 36~50h; The calcination temperature is 600~800℃, and the time is 3~8h.

8. The preparation method according to claim 7, characterized in that, The AgMo powder was prepared by chemical plating. Preferably, the method for preparing AgMo powder includes the following steps: a) Molybdenum powder was sensitized in a sensitizing solution and then activated in an activation solution to obtain the treated molybdenum powder; b) After mixing the treated molybdenum powder with the reducing solution, silver ammonia solution is added to react and AgMo metal powder is obtained. Preferably, the particle size of the molybdenum powder is 1~3μm; The sensitizing solution comprises 10-20 g / L SnCl2·2H2O and 55-80 ml / L HCl; The sensitization time is 5-8 minutes; The activation solution comprises 0.2~0.5 g / L of PdCl2 and 15~25 ml / L of HCl; The activation time is 5-8 minutes; During the activation process, the amount of molybdenum powder added to the activation solution is 40~60 g / L; The reducing solution comprises 10-15 g / L glucose and 100-115 g / L tartaric acid; The silver ammonia solution is a transparent solution obtained by adding 30-35 mL / L NaOH aqueous solution to 0.05-0.15 mol / L AgNO3 aqueous solution to form AgOH precipitate, followed by adding ammonia. The reaction time is 40-60 minutes; The reaction process includes washing and drying, wherein the drying is performed under vacuum at 40°C and then dried at 50-60°C for 45-60 minutes.

9. The preparation method according to claim 5, characterized in that, The calcination temperature is 800℃~900℃, and the time is 2~4h.

10. A lubricating and wear-resistant coating, characterized in that, It is prepared from the spraying powder according to any one of claims 1 to 4.

Images