Titanium-based mixed powder for laser cladding coating and manufacturing method

Abstract

This application provides a titanium-based mixed powder for laser cladding coatings and a manufacturing method. The mixed powder comprises the following raw materials in parts by weight: 50 parts titanium powder, 2-4 parts carbon nanotubes, 5-6 parts carbon black, 1-3 parts graphite, 12-15 parts silicon silicide, and 5-7 parts graphite fluoride. The titanium-based mixed powder used in this application is used to prepare laser cladding coatings, which exhibit excellent performance.

Description

Technical Field

[0001] The present application relates to the technical field related to metal coatings, and in particular to a titanium-based mixed powder for laser cladding coatings and a manufacturing method thereof. Background Art

[0002] Laser cladding uses cladding materials that have good compatibility but are mostly different from the matrix composition. Laser beam heating is used to prepare a cladding layer on the alloy surface that forms a good metallurgical bond with the alloy matrix, thereby improving the hardness, oxidation resistance, corrosion resistance, wear resistance and biological properties of the matrix surface.

[0003] Cladding materials are laser-clad under appropriate process parameters to form a cladding layer. The cladding material directly influences the chemical composition of the coating. Cladding materials can be categorized by form as powder, wire, or sheet. Powders interact well with the laser during use and offer flexible application options, making them the most widely used and versatile cladding material.

[0004] Ceramic particles are the primary reinforcing phase in composite cladding layers, playing a key role in improving the hardness and wear resistance of the cladding layer. There are many types of ceramic particles, including oxide ceramics, carbide ceramics, nitrides, and borides. Carbide ceramics can be divided into metal carbides (such as TiC) and non-metallic carbides (such as SiC). However, during the cladding process, carbide ceramic particles tend to agglomerate and are not evenly distributed within the cladding layer, affecting the cladding layer's hardness and wear resistance. Summary of the Invention

[0005] The present application is made in view of the above problems, and its purpose is to provide a titanium-based mixed powder for laser cladding coating, and the laser cladding coating prepared by using the powder has high hardness and good wear resistance.

[0006] Specifically, the first aspect of the present application provides a titanium-based mixed powder for laser cladding coating, comprising the following raw materials in parts by weight:

[0007] 50 parts of Ti powder, 2 to 4 parts of carbon nanotubes, 5 to 6 parts of carbon black, 1 to 3 parts of graphite, 12 to 15 parts of silicon carbide and 5 to 7 parts of graphite fluoride.

[0008] According to one of the technical solutions of the titanium-based mixed powder technology of this application, at least the following beneficial effects are achieved:

[0009] The raw materials for preparing the titanium-based mixed powder in the present application include Ti powder, carbon nanotubes, carbon black, graphite, silicon carbide and graphite fluoride; among them, titanium powder is used as a titanium source to form titanium carbide and titanium silicon carbide (Ti3SiC2); during the preparation process, carbon nanotubes, carbon black, graphite and graphite fluoride react with titanium powder to form titanium carbide, and titanium powder reacts with silicon carbide to form titanium silicon carbide.

[0010] Carbon nanotubes are fibrous with a small diameter, carbon black is granular, and graphite is a soft phase with strong adhesion and a relatively large contact area. The three are used to form a three-dimensional structure of points, lines and surfaces, which has a certain supporting effect on titanium powder, can promote full contact between titanium powder and carbon materials, and thus facilitate the formation of uniform titanium carbide materials.

[0011] In this application, graphite fluoride is also used to promote the formation of titanium carbide. During the reaction, graphite fluoride will partially decompose to produce F atoms and highly active carbon. The F atoms are highly active and will first react with Ti powder to form TiF3; TiF3 will further react with highly active carbon to form TiC and fluorine atoms, thereby promoting the formation of TiC.

[0012] The present application also controls the ratio of titanium carbide to silicon titanium carbide by controlling the weight portions of the raw materials, thereby producing a mixed powder with excellent performance.

[0013] According to some embodiments of the present application, the particle size of the titanium powder is 20 μm to 30 μm.

[0014] According to some embodiments of the present application, the diameter of the carbon nanotube is 5 nm to 15 nm.

[0015] According to some embodiments of the present application, the particle size of the carbon black is 40 nm to 50 nm.

[0016] According to some embodiments of the present application, the particle size of the graphite is 40 μm to 50 μm.

[0017] According to some embodiments of the present application, the fluorine-to-carbon ratio of the fluorinated graphite is 1.1-1.2.

[0018] Graphite fluoride is a covalent bond graphite intercalation compound composed of carbon and fluorine. It has a layered structure, and fluorine atoms are its intercalation substances. The molecular formula is generally (CF x ) n express;

[0019] Due to the introduction of fluorine atoms, C-F bonds are formed in the graphite. Fluorinated graphite with a high degree of fluorination can react with titanium powder to form TiC. The pyrolysis temperature of highly fluorinated graphite reaches the temperature at which fluorine reacts with titanium. The C-F bonds break and react with titanium, further releasing a large amount of heat and promoting the reaction between carbon and titanium. Fluorinated graphite with a high degree of fluorination has a high concentration of C-F bonds. After the chemical bonds break, the concentration of highly active carbon particles formed is high and easy to react with titanium. The interlayer spacing of highly fluorinated graphite is larger, which is conducive to the infiltration of titanium particles and the reaction with carbon. The influence of multiple favorable factors promotes the reaction between highly fluorinated graphite and titanium powder to produce the target product TiC.

[0020] For fluorinated graphite with a fluorine-carbon atomic ratio greater than 1.1, since the fluorine in the fluorinated graphite exists completely in the form of CF covalent bonds, while the carbon atoms (CF) exist in sp3 hybrid orbitals, the planarity of the graphite layer changes and forms wrinkles, which is more conducive to the formation of titanium carbide.

[0021] According to some embodiments of the present application, the particle size of the fluorinated graphite is 5 μm to 10 μm.

[0022] According to some embodiments of the present application, the silicon carbide includes the following preparation raw materials in parts by weight:

[0023] 1 part of silica sol and 3 to 7 parts of graphite powder.

[0024] The present application adopts silica sol and graphite powder to form silicon carbide; utilizes the reaction of silica sol and graphite powder to facilitate the formation of small-sized silicon carbide material; facilitates the full contact between silicon carbide material and titanium powder, thereby promoting titanium silicon carbon material.

[0025] According to some embodiments of the present application, the particle size of the graphite powder is 100 μm to 200 μm.

[0026] The second aspect of the present application provides a method for preparing the titanium-based mixed powder for laser cladding coating, comprising the following steps:

[0027] Mixing the prepared raw materials, pressing into shape, and sintering under high pressure;

[0028] The pressure of the high pressure sintering is 20MPa~50MPa;

[0029] The high pressure sintering temperature is 1000°C to 1600°C.

[0030] According to one of the technical solutions of the preparation method of this application, at least the following beneficial effects are achieved:

[0031] The present application is sintered under high pressure and high temperature conditions, so that the raw materials are fully combined with each other, so that the final material has good toughness, thereby enhancing the mechanical properties of the material.

[0032] According to some embodiments of the present application, the mixing is ball milling mixing.

[0033] According to some embodiments of the present application, the mixed medium is ethanol.

[0034] According to some embodiments of the present application, the rotation speed of the ball milling mixing is 100 r / min~200 r / min.

[0035] According to some embodiments of the present application, the high-pressure sintering includes a first stage sintering, a second stage sintering, and a third stage sintering.

[0036] According to some embodiments of the present application, the temperature of the first sintering stage is 1000°C~1100°C.

[0037] According to some embodiments of the present application, the time of the first sintering stage is 0.5h~1.5h.

[0038] According to some embodiments of the present application, the pressure of the first sintering stage is 20 MPa~30 MPa.

[0039] According to some embodiments of the present application, the temperature of the second sintering stage is 1200°C~1400°C.

[0040] According to some embodiments of the present application, the pressure of the second sintering stage is 40 MPa~50 MPa.

[0041] According to some embodiments of the present application, the second sintering time is 1.5 hours to 2.5 hours.

[0042] According to some embodiments of the present application, the temperature of the third sintering stage is 1450°C~1600°C.

[0043] According to some embodiments of the present application, the pressure of the third sintering stage is 35 MPa~40 MPa.

[0044] According to some embodiments of the present application, the third sintering time is 0.3h~0.7h.

[0045] In the present application, the pressure and time of the first, second and third sintering stages are controlled to control the degree of bonding and content of the ultimately formed titanium carbide and titanium silicon carbon. During the first and second sintering stages, the titanium silicon carbon phase is preferentially formed, while during the third sintering stage, silicon is easily evaporated and lost. Under high pressure, the evaporation and escape of internal silicon is blocked, thereby achieving control of the final titanium carbide content and titanium silicon carbon content, thereby achieving control of the properties of the ultimately formed material.

[0046] Among them, the hardness of titanium carbide is higher than that of titanium silicon carbide, but its machinability is poor; by regulating the content of silicon carbide and silicon titanium carbide, it is beneficial to control the hardness of the material and improve its processing performance, thereby producing a titanium-based mixed powder with excellent performance.

[0047] According to some embodiments of the present application, the first stage is further subjected to heat treatment before sintering.

[0048] According to some embodiments of the present application, the temperature of the heat treatment is 400°C to 500°C.

[0049] According to some embodiments of the present application, the heat treatment time is 2h~3h.

[0050] According to some embodiments of the present application, the method for preparing the silica sol comprises the following steps:

[0051] TEOS, ethanol, water and hydrochloric acid are mixed and reacted;

[0052] The mass fraction of the hydrochloric acid is 30% to 37%.

[0053] According to some embodiments of the present application, the molar ratio of tetraethyl orthosilicate to ethanol is 1:5~7.

[0054] According to some embodiments of the present application, the molar ratio of tetraethyl orthosilicate to water is 1:5~7.

[0055] According to some embodiments of the present application, the molar ratio of the tetraethyl orthosilicate to the hydrogen chloride in the hydrochloric acid is 1:0.1~0.3.

[0056] According to some embodiments of the present application, the compression molding pressure is 5 MPa~10 MPa.

[0057] According to some embodiments of the present application, the pressing time is 5s~30s.

[0058] The present application adopts a sol-gel carbon thermal reduction reaction method to prepare silicon carbide material, and then mixes the silicon carbide material, carbon nanotubes, carbon black, graphite and fluorinated graphite with titanium powder and performs high-pressure and high-temperature sintering to form a titanium carbide and silicon titanium carbide composite material. The titanium carbide and silicon titanium carbide are interspersed with each other and evenly distributed in the system, thereby producing a titanium-based mixed powder with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0060] Figure 1 This is an SEM image of the laser cladding coating prepared using the titanium-based mixed powder in Example 1 of the present application.

[0061] The purpose, features and advantages of this drawing will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making any creative work are within the scope of protection of this application.

[0063] Obviously, the following descriptions are merely some examples or embodiments of the present application. Those skilled in the art can apply the present application to other similar scenarios without inventive effort. Furthermore, it is also understood that, although the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in the present application, changes in design, manufacturing, or production based on the technical content disclosed in the present application are merely conventional technical means and should not be construed as an insufficiency of the content disclosed in the present application.

[0064] Graphite fluoride, specification: DBSF2050; average particle size: 5μm~10μm; fluorine-carbon ratio: 1.15.

[0065] Silicon carbide, the preparation method of silicon carbide in this application, consists of the following steps:

[0066] S1. Mix the wastewater ethanol and ethyl orthosilicate and stir them evenly. Then add water and a 37% hydrochloric acid solution and stir them evenly (stir and react at 25°C for 30 minutes) to obtain a silica sol.

[0067] The molar ratio of anhydrous ethanol, ethyl orthosilicate, water and hydrogen chloride in the hydrochloric acid solution is 3:0.6:3:0.1;

[0068] S2. adding graphite powder (average particle size of 150 μm, mass ratio of graphite powder to silica sol of 1:5) to the silica sol obtained in step S1, stirring for 20 minutes, and drying at 100° C. for 12 hours to obtain graphite powder coated with silica sol;

[0069] S3. Reduce the graphite powder coated with the silica sol obtained in step S2 at 1350° C. for 2 h (the atmosphere is argon and the heating rate is 5° C. / min) to obtain silicon carbide.

[0070] Example 1

[0071] This embodiment is a mixed powder for laser coating, which is composed of the following raw materials in parts by weight:

[0072] 50 parts of Ti powder, 3.4 parts of carbon nanotubes, 5.4 parts of carbon black, 2.4 parts of graphite, 13.8 parts of silicon carbide and 6.4 parts of graphite fluoride.

[0073] The particle size (D50) of titanium powder is 25 μm; the average diameter of carbon nanotubes is 10 nm; the particle size (D50) of carbon black is 45 nm; and the particle size (D50) of graphite is 45 μm.

[0074] The method for preparing the mixed powder for laser coating in this embodiment comprises the following steps:

[0075] S1. Mix the prepared raw materials (50 g of titanium powder and other materials in proportion) and then ball mill;

[0076] Ball milling parameters are as follows:

[0077] The medium is anhydrous ethanol, zirconia balls are used as grinding balls, the speed of ball milling is 180r / min, and the ball milling time is 15h.

[0078] The diameter of the zirconia ball is φ5 mm, and the mass ratio of the zirconia ball, the preparation raw materials and anhydrous ethanol is 2:1:2.

[0079] After ball milling, the mixture was dried at 60°C for 20 h, fully ground and pulverized, and then passed through a 200-mesh sieve to prepare a mixed powder.

[0080] S2. The mixed powder obtained in step S1 is placed into a mold and pressed at a pressure of 10 MPa for 10 seconds to form the mixture.

[0081] S3. Place the powder pressed in step S2 in a hot pressing sintering furnace, heat it to 450°C under argon protection, and keep it there for 2 hours (heating rate of 10°C / min); after the heat preservation, sinter it under high pressure (heating rate of 5°C / min);

[0082] High pressure sintering includes the first stage sintering, the second stage sintering and the third stage sintering.

[0083] The temperature of the first sintering stage is 1050° C., the time of the first sintering stage is 1 h, and the pressure of the first sintering stage is 25 MPa.

[0084] The temperature was increased during the first and second sintering stages at a rate of 5°C / min;

[0085] The temperature of the second sintering stage is 1300° C., the pressure of the second sintering stage is 45 MPa, and the time of the second sintering stage is 2 h.

[0086] The temperature was increased during the second and third sintering stages at a rate of 5°C / min;

[0087] The temperature of the third sintering stage is 1500° C., the pressure of the third sintering stage is 40 MPa, and the time of the third sintering stage is 0.5 h.

[0088] After the third stage of sintering is completed, the furnace is cooled.

[0089] Example 2

[0090] This embodiment is a mixed powder for laser coating, which is composed of the following raw materials in parts by weight:

[0091] 50 parts of Ti powder, 2 parts of carbon nanotubes, 6 parts of carbon black, 1 part of graphite, 15 parts of silicon carbide and 5 parts of graphite fluoride.

[0092] The particle size (D50) of titanium powder is 25 μm; the average diameter of carbon nanotubes is 10 nm; the particle size (D50) of carbon black is 45 nm; and the particle size (D50) of graphite is 45 μm.

[0093] The method for preparing the mixed powder for laser coating in this embodiment comprises the following steps:

[0094] S1. Mix the prepared raw materials (50 g of titanium powder and other materials in proportion) and then ball mill;

[0095] Ball milling parameters are as follows:

[0096] The medium is anhydrous ethanol, zirconia balls are used as grinding balls, the speed of ball milling is 180r / min, and the ball milling time is 15h.

[0097] The diameter of the zirconia ball is φ5 mm, and the mass ratio of the zirconia ball, the preparation raw materials and anhydrous ethanol is 2:1:2.

[0098] After ball milling, the mixture was dried at 60°C for 20 h, fully ground and pulverized, and then passed through a 200-mesh sieve to prepare a mixed powder.

[0099] S2. The mixed powder obtained in step S1 is placed into a mold and pressed at a pressure of 10 MPa for 10 seconds to form the mixture.

[0100] S3. Place the powder pressed in step S2 in a hot pressing sintering furnace, heat it to 450°C under argon protection, and keep it there for 2 hours (heating rate of 10°C / min); after the heat preservation, sinter it under high pressure (heating rate of 5°C / min);

[0101] High pressure sintering includes the first stage sintering, the second stage sintering and the third stage sintering.

[0102] The temperature of the first sintering stage is 1000° C., the time of the first sintering stage is 1 h, and the pressure of the first sintering stage is 20 MPa.

[0103] The temperature was increased during the first and second sintering stages at a rate of 5°C / min;

[0104] The temperature of the second sintering stage is 1400° C., the pressure of the second sintering stage is 50 MPa, and the time of the second sintering stage is 1.5 h.

[0105] The temperature was increased during the second and third sintering stages at a rate of 5°C / min;

[0106] The temperature of the third sintering stage is 1450° C., the pressure of the third sintering stage is 35 MPa, and the time of the third sintering stage is 0.3 h.

[0107] After the third stage of sintering is completed, the furnace is cooled.

[0108] Example 3

[0109] This embodiment is a mixed powder for laser coating, which is composed of the following raw materials in parts by weight:

[0110] 50 parts of Ti powder, 4 parts of carbon nanotubes, 5 parts of carbon black, 3 parts of graphite, 12 parts of silicon carbide and 7 parts of graphite fluoride.

[0111] The particle size (D50) of titanium powder is 25 μm; the average diameter of carbon nanotubes is 10 nm; the particle size (D50) of carbon black is 45 nm; and the particle size (D50) of graphite is 45 μm.

[0112] The method for preparing the mixed powder for laser coating in this embodiment comprises the following steps:

[0113] S1. Mix the prepared raw materials (50 g of titanium powder and other materials in proportion) and then ball mill;

[0114] Ball milling parameters are as follows:

[0115] The medium is anhydrous ethanol, zirconia balls are used as grinding balls, the speed of ball milling is 180r / min, and the ball milling time is 15h.

[0116] The diameter of the zirconia ball is φ5 mm, and the mass ratio of the zirconia ball, the preparation raw materials and anhydrous ethanol is 2:1:2.

[0117] After ball milling, the mixture was dried at 60°C for 20 h, fully ground and pulverized, and then passed through a 200-mesh sieve to prepare a mixed powder.

[0118] S2. The mixed powder obtained in step S1 is placed into a mold and pressed at a pressure of 10 MPa for 10 seconds to form the mixture.

[0119] S3. Place the powder pressed in step S2 in a hot pressing sintering furnace, heat it to 450°C under argon protection, and keep it there for 2 hours (heating rate of 10°C / min); after the heat preservation, sinter it under high pressure (heating rate of 5°C / min);

[0120] High pressure sintering includes the first stage sintering, the second stage sintering and the third stage sintering.

[0121] The temperature of the first sintering stage is 1100° C., the time of the first sintering stage is 0.5 h, and the pressure of the first sintering stage is 30 MPa.

[0122] The temperature was increased during the first and second sintering stages at a rate of 5°C / min;

[0123] The temperature of the second sintering stage is 1200° C., the pressure of the second sintering stage is 40 MPa, and the time of the second sintering stage is 2.5 h.

[0124] The temperature was increased during the second and third sintering stages at a rate of 5°C / min;

[0125] The temperature of the third sintering stage is 1600° C., the pressure of the third sintering stage is 40 MPa, and the time of the third sintering stage is 0.3 h.

[0126] After the third stage of sintering is completed, the furnace is cooled.

[0127] Example 4

[0128] This embodiment is a mixed powder for laser coating, which differs from Example 1 in that:

[0129] In the preparation method of this embodiment, no heat treatment is performed in step S3.

[0130] That is, the temperature is directly raised to the first sintering temperature under argon protection.

[0131] The first stage of heating is carried out at a rate of 10°C / min, and the temperature is raised to 450°C; then the second stage of heating is carried out at a rate of 5°C / min.

[0132] Example 5

[0133] This embodiment is a mixed powder for laser coating, which differs from Example 1 in that:

[0134] In the preparation method of this embodiment, the high-pressure sintering in step S3 is a one-stage sintering.

[0135] The sintering temperature is 1500°C, the sintering pressure is 40 MPa, and the sintering time is 4 h.

[0136] After the third stage of sintering is completed, the furnace is cooled.

[0137] Comparative Example 1

[0138] This comparative example is a mixed powder for laser coating, which differs from Example 5 in that:

[0139] The mixed powder in this comparative example is composed of the following raw materials in parts by weight:

[0140] 50 parts of Ti powder, 10 parts of carbon nanotubes, 5.4 parts of carbon black, 2.4 parts of graphite and 6.4 parts of fluorinated graphite.

[0141] The particle size (D50) of titanium powder is 25 μm; the average diameter of carbon nanotubes is 10 nm; the particle size (D50) of carbon black is 45 nm; and the particle size (D50) of graphite is 45 μm.

[0142] Comparative Example 2

[0143] This comparative example is a mixed powder for laser coating, which differs from Example 5 in that:

[0144] The mixed powder in this comparative example is composed of the following raw materials in parts by weight:

[0145] 50 parts of Ti powder, 8.4 parts of carbon black, 2.8 parts of graphite, 13.8 parts of silicon carbide and 6.4 parts of graphite fluoride.

[0146] The particle size (D50) of titanium powder is 25 μm; the average diameter of carbon nanotubes is 10 nm; the particle size (D50) of carbon black is 45 nm; and the particle size (D50) of graphite is 45 μm.

[0147] Comparative Example 3

[0148] This comparative example is a mixed powder for laser coating, which differs from Example 5 in that:

[0149] The mixed powder in this comparative example is composed of the following raw materials in parts by weight:

[0150] 50 parts of Ti powder, 6.2 parts of carbon nanotubes, 5 parts of graphite, 13.8 parts of silicon carbide and 6.4 parts of graphite fluoride.

[0151] The particle size (D50) of titanium powder is 25 μm; the average diameter of carbon nanotubes is 10 nm; and the particle size (D50) of graphite is 45 μm.

[0152] Comparative Example 4

[0153] This comparative example is a mixed powder for laser coating, which differs from Example 5 in that:

[0154] The mixed powder in this comparative example is composed of the following raw materials in parts by weight:

[0155] 50 parts of Ti powder, 3.4 parts of carbon nanotubes, 5.4 parts of carbon black, 5.6 parts of graphite, and 13.8 parts of silicon carbide.

[0156] The particle size (D50) of titanium powder is 25 μm; the average diameter of carbon nanotubes is 10 nm; the particle size (D50) of carbon black is 45 nm; and the particle size (D50) of graphite is 45 μm.

[0157] Comparative Example 5

[0158] This comparative example is a mixed powder for laser coating, which differs from Example 5 in that:

[0159] The mixed powder in this comparative example is composed of the following raw materials in parts by weight:

[0160] 50 parts of Ti powder, 16.6 parts of graphite and 13.8 parts of silicon carbide.

[0161] The particle size (D50) of titanium powder is 25 μm; the particle size (D50) of graphite is 45 μm.

[0162] Application Examples

[0163] The mass ratio of the titanium-based mixed powder prepared in the examples and comparative examples of the present application to the cobalt powder (D50 is 100 μm) is 1:19.

[0164] S1. The above raw materials were placed in a planetary ball mill and ball milled for 2 h to obtain an alloy powder mixture, which was then dried in a vacuum drying oven at 100° C. for 2 h;

[0165] Ball milling parameters are as follows:

[0166] Zirconia balls were used as grinding balls, the speed of ball milling was 180 r / min, and the ball milling time was 15 h.

[0167] S2. Grind the TC4 alloy substrate using 400 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh sandpaper in sequence;

[0168] S3, using LDM-8060 powder feeding laser to scan the surface of TC4 alloy substrate using synchronous powder feeding method to form a composite coating on the surface of TC4 alloy substrate;

[0169] Among them, the output power is 1.7kW, the spot diameter is 3mm, the scanning speed is 12mm / s, the powder feeding rate is 12g / min, the defocus amount is -1mm, and the overlap rate is 50%.

[0170] The performance of the composite coatings corresponding to the examples of the present application and the comparative examples was tested, and the test results are shown in Table 1.

[0171] Table 1 .

[0172] The difference between Example 4 and Example 1 is that without heat treatment, the promoting effect of graphite fluoride becomes worse, resulting in a decrease in TiC content and a lower hard phase content, resulting in a lower average microhardness.

[0173] The difference between Example 5 and Example 1 is that sintering at a single temperature results in a greater degree of desiliconization, a lower silicon carbide content, greater processing difficulty, and worse uniformity of hard phase distribution, resulting in a lower average microhardness.

[0174] The difference between Comparative Example 1 and Example 5 is that without adding silicon carbide, silicon titanium carbide cannot be formed, and pure titanium carbide is difficult to process, resulting in poor uniformity of hard phase distribution and lower average microhardness.

[0175] The difference between Comparative Example 2 and Example 5 is that carbon nanotubes are not added, and graphite and carbon black are used instead of carbon nanotubes, which results in the inability to form a three-dimensional structure of points, lines and surfaces, which is not conducive to the formation of a uniform titanium carbide material; resulting in a deterioration in the uniformity of the hard phase distribution, resulting in a lower average microhardness.

[0176] The difference between Comparative Example 3 and Example 5 is that carbon black is not added, and graphite and carbon nanotubes are used instead of carbon black, which results in the inability to form a three-dimensional structure of points, lines and surfaces, which is not conducive to the formation of a uniform titanium carbide material; resulting in a deterioration in the uniformity of the hard phase distribution, resulting in a lower average microhardness.

[0177] The difference between Comparative Example 4 and Example 5 is that no fluorinated graphite is added and graphite is used instead of fluorinated graphite, resulting in a decrease in TiC content and a lower hard phase content, resulting in a lower average microhardness.

[0178] The difference between Comparative Example 5 and Example 5 is that carbon black, fluorinated graphite and carbon nanotubes are not added, and graphite is partially replaced, resulting in the inability to form a three-dimensional structure of points, lines and surfaces, which is not conducive to the formation of uniform titanium carbide material and cannot promote the formation of TiC; resulting in a lower content of hard phase and worse distribution uniformity, resulting in a lower average microhardness.

[0179] The reasons for the improved hardness in the embodiments of the present application are as follows: first, dispersion strengthening: the strong convection generated in the molten pool causes the hard phase (TiC) in the composite coating to be evenly distributed in the cladding layer; second, the excellent properties of the composite alloy powder system can improve the mechanical properties of the composite coating.

[0180] The mixed powder used for laser coating in this application is made from a Co-Ti3SiC2-TiC alloy powder. A composite coating is prepared on the surface of a TC4 alloy substrate. Co acts as a toughening phase, Ti3SiC2 as a reinforcing phase, and TiC as a strengthening phase. These three phases synergistically enhance the performance of the composite coating. Compared to the TC4 alloy substrate, the composite coating significantly increases its average hardness, significantly improving the surface wear resistance of the TC4 alloy substrate.

[0181] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A titanium-based mixed powder for laser cladding coating, characterized in that: The preparation comprises the following raw materials in parts by weight: 50 parts of Ti powder, 2 to 4 parts of carbon nanotubes, 5 to 6 parts of carbon black, 1 to 3 parts of graphite, 12 to 15 parts of silicon carbide, and 5 to 7 parts of graphite fluoride; The silicon carbide comprises the following raw materials in parts by weight: 1 part of silica sol and 3 to 7 parts of graphite powder.

2. The titanium-based mixed powder for laser cladding coating according to claim 1, characterized in that: The particle size of the Ti powder is 20 μm to 30 μm; The diameter of the carbon nanotubes is 5 nm to 15 nm; The particle size of the carbon black is 40nm~50nm; The particle size of the graphite is 40 μm to 50 μm.

3. The titanium-based mixed powder for laser cladding coating according to claim 1, characterized in that: The fluorine-carbon atomic ratio of the fluorinated graphite is 1.1-1.2:1; The particle size of the fluorinated graphite is 5 μm to 10 μm.

4. The titanium-based mixed powder for laser cladding coating according to claim 1, characterized in that: The particle size of the graphite powder is 100 μm to 200 μm.

5. A method for producing a titanium-based mixed powder for laser cladding coating according to any one of claims 1 to 4, characterized in that: The following steps are involved: Mixing the prepared raw materials, pressing into shape, and sintering under high pressure; The pressure of the high pressure sintering is 20MPa~50MPa; The high pressure sintering temperature is 1000°C to 1600°C.

6. The manufacturing method according to claim 5, characterized in that The mixing is ball milling mixing, and the mixing medium is ethanol; The rotation speed of the ball milling mixing is 100 r / min~200 r / min.

7. The manufacturing method according to claim 5, characterized in that The high pressure sintering includes a first stage sintering, a second stage sintering and a third stage sintering; The temperature of the first sintering stage is 1000° C. to 1100° C., and the time of the first sintering stage is 0.5 h to 1.5 h; The temperature of the second sintering stage is 1200° C. to 1400° C., and the time of the second sintering stage is 1.5 h to 2.5 h; The temperature of the third sintering stage is 1450° C. to 1600° C., and the time of the third sintering stage is 0.3 h to 0.7 h.

8. The manufacturing method according to claim 5, characterized in that The preparation method of the silica sol comprises the following steps: TEOS, ethanol, water and hydrochloric acid are mixed and reacted; The mass fraction of the hydrochloric acid is 30% to 37%.

9. The manufacturing method according to claim 8, characterized in that The molar ratio of the tetraethyl orthosilicate to ethanol is 1:5-7; The molar ratio of the tetraethyl orthosilicate to water is 1:5-7; The molar ratio of the ethyl orthosilicate to the hydrogen chloride in the hydrochloric acid is 1:0.1-0.

3.

10. The manufacturing method according to claim 5, characterized in that The pressure of the compression molding is 5MPa~10MPa.

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