Self-fluxing hard alloy spherical powder and preparation method thereof

Abstract

The invention discloses self-fluxing hard alloy spherical powder and a preparation method thereof, and belongs to the technical field of powder preparation. The preparation method comprises the following steps: mixing and ball-milling a hard phase material, a binding phase material and a fluxing agent material, and then sintering to obtain a self-fluxing hard alloy blank; and then the self-fluxing hard alloy blank is subjected to electric arc micro-explosion, reduction and screening treatment, and the self-fluxing hard alloy spherical powder is obtained. The obtained self-fluxing hard alloy spherical powder is uniform in component, can be designed in a customized mode according to needs, is small in particle size, high in sphericity degree and low in oxygen content, keeps the original performance of the alloy, can be applied to the field of cladding processing, is not prone to material segregation, and can be used for preparing cladding layer products with uniform components.

Description

Technical Field

[0001] The invention relates to the technical field of powder preparation, in particular to a self-fluxing cemented carbide spherical powder and a preparation method thereof. Background Art

[0002] With the continuous development of industrial technology, the metal powder cladding application market is expanding rapidly, especially the application value of cemented carbide spherical powder is greater. In the cladding process, it is often necessary to mix and prepare different types of metal powders according to the process requirements to achieve the final cladding effect.

[0003] The preparation methods of metal powders generally include: grinding and crushing, spray granulation and drying, gas atomization, water atomization, plasma atomization, spheroidization, rotating electrode atomization, etc. The composition of the metal powders obtained by the above methods is limited by the composition of the raw materials, the composition is relatively single, and the mixing between different metal powders is uneven. However, in the metal powder cladding process, it is usually necessary to mix and compound different types of metal powders, and then perform cladding processing to obtain the desired cladding layer product. If it can only be mixed by physical methods such as stirring, it is difficult to ensure the uniformity of the composition of different types of metal powder materials. Moreover, the metal powder raw materials mixed by traditional stirring methods are prone to material segregation during the cladding process, which will directly affect the cladding process quality and thus affect the uniformity of the cladding layer product. Summary of the invention

[0004] Based on this, the present invention mainly provides a self-fluxing cemented carbide spherical powder and a preparation method thereof, so as to solve the technical problems that when preparing cladding layer products by cladding processing, the raw material alloy metal powder is unevenly mixed, material segregation is prone to occur, and the composition of the prepared cladding layer products is uneven.

[0005] To achieve the above object, the present invention provides a method for preparing self-fluxing cemented carbide spherical powder, comprising the following steps:

[0006] S10, mixing and ball-milling the hard phase material, the binder phase material, and the flux material, and then sintering to obtain a self-fluxing cemented carbide blank;

[0007] S20, connecting the self-fluxing cemented carbide blank to the positive electrode of a pulse power supply, connecting the graphite electrode to the negative electrode of the pulse power supply, applying a current between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply to form an arc discharge, and forming a molten pit on the surface of the self-fluxing cemented carbide blank;

[0008] S30, introducing a high-pressure fluid between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply, so that the high-pressure fluid rushes through the molten pit, causing the molten pit to explode and produce small droplets, and the small droplets are cooled to obtain primary self-fluxing cemented carbide spherical powder;

[0009] S40, reducing and sieving the primary self-fluxing cemented carbide spherical powder to obtain self-fluxing cemented carbide spherical powder.

[0010] In some embodiments of the present invention, the hard phase material includes at least one of WC, CrC, TiC, SiC, Al2O3, ZrO, AlN, TiN, TaN, BN, P3N5, Si3N4, and ZnB;

[0011] The bonding phase material includes at least one of Co, Ni, Fe, Cu, and Mo;

[0012] The flux material includes B and Si.

[0013] In some embodiments of the present invention, based on the total mass of the hard phase material, the bonding phase material and the flux material being 100%, the weight percentage of the hard phase material is greater than or equal to 50%; and / or the weight percentage of the flux material is less than or equal to 5%.

[0014] In some embodiments of the present invention, the high-pressure fluid includes high-pressure water flow and / or high-pressure gas.

[0015] In some embodiments of the present invention, the high-pressure fluid is a high-pressure gas, and the high-pressure gas includes high-pressure air, high-pressure nitrogen, high-pressure argon and / or high-pressure helium.

[0016] In some embodiments of the present invention, the sintering temperature is 1400° C. to 1500° C.; and the sintering time is greater than or equal to 6 hours.

[0017] In some embodiments of the present invention, in step S20, the applied current is above 300A.

[0018] In some embodiments of the present invention, in the step S40, the primary self-fluxing cemented carbide spherical powder is subjected to a reduction treatment in a hydrogen atmosphere.

[0019] In some embodiments of the present invention, the screening method includes ultrasonic vibration screening treatment or air flow classification screening treatment.

[0020] The present invention also provides a self-fluxing cemented carbide spherical powder prepared by the method for preparing the self-fluxing cemented carbide spherical powder.

[0021] The beneficial effects that can be achieved by the present invention are:

[0022] The present invention compounds a hard phase material, a bonding phase material and a flux material, and obtains a self-fluxing cemented carbide blank through sufficient ball milling, mixing and sintering. The self-fluxing cemented carbide blank is used as a raw material in a cladding process for cladding treatment. Because the self-fluxing cemented carbide blank is obtained by pre-mixing different types of metal powders according to a certain weight ratio, a customized ratio can be made in the stage of preparing the self-fluxing hard metal spherical powder according to the component requirements of the cladding layer product, and then physical mixing in ball milling and chemical mixing in the sintering process are performed, and finally arc micro-explosion treatment is performed to easily obtain a self-fluxing cemented carbide spherical powder with uniform composition, high sphericity, lower cost and less surface oxide. The self-fluxing cemented carbide spherical powder is applied to the cladding process, material segregation is not likely to occur, and a cladding layer product with uniform composition can be prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0024] Figure 1 The figure is a schematic diagram of the preparation process of self-fluxing cemented carbide spherical powder according to an embodiment of the present invention.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] In cladding processes, such as laser cladding and plasma cladding, it is usually necessary to compound and mix different types of metal powders according to needs, and then perform cladding treatment to obtain the desired product. For example, it is usually necessary to mix and compound hard phase metal powders and binder phase metal powders, and then perform cladding treatment to obtain the desired product. However, different types of metal powders are usually mixed by physical stirring before cladding treatment, which makes it difficult to achieve uniform mixing of different types of metals. Moreover, material segregation is likely to occur during cladding processing, which will directly affect the quality of subsequent cladding processing, resulting in problems such as uneven composition of the cladding product.

[0030] In view of this, the present invention provides a method for preparing self-fluxing cemented carbide spherical powder, referring to Figure 1 , including the following steps:

[0031] S10, mixing and ball-milling the hard phase material, the binder phase material, and the flux material, and then sintering to obtain a self-fluxing cemented carbide blank;

[0032] S20, connecting the self-fluxing cemented carbide blank to the positive electrode of a pulse power supply, connecting the graphite electrode to the negative electrode of the pulse power supply, applying a current between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply to form an arc discharge, and forming a molten pit on the surface of the self-fluxing cemented carbide blank;

[0033] S30, introducing a high-pressure fluid between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply, so that the high-pressure fluid rushes through the molten pit, prompting the molten pit to produce small droplets, and the small droplets are cooled to obtain primary self-fluxing cemented carbide spherical powder;

[0034] S40, reducing and sieving the primary self-fluxing cemented carbide spherical powder to obtain self-fluxing cemented carbide spherical powder.

[0035] The present invention compounds hard phase material, bonding phase material and flux material, and obtains self-fluxing cemented carbide blank after sufficient ball milling, mixing and sintering. The self-fluxing cemented carbide blank is used as the raw material in the metal powder cladding process, and the cladding process is performed. Because the self-fluxing cemented carbide blank is a mixture of different types of metal powders in advance according to a certain weight ratio, the self-fluxing cemented carbide blank can be customized according to the composition requirements of the cladding layer product at the stage of preparing the self-fluxing hard metal spherical powder, and then physical mixing of mixed ball milling, chemical mixing during the sintering process, and then arc micro-explosion treatment are performed to easily obtain self-fluxing cemented carbide spherical powder with uniform composition, high sphericity, lower cost, and less surface oxides. The self-fluxing cemented carbide spherical powder is applied to the cladding process, and material segregation is not easy to occur, and a cladding layer product with uniform composition can be prepared.

[0036] In the present invention, the bonding phase material is a common raw material in metal cladding processing. In the process of preparing the self-fluxing cemented carbide blank, it can also enhance the bonding force between the hard phase materials and improve the toughness and impact resistance of the alloy. The flux material can inhibit the growth of grains, which is conducive to obtaining finer grains and improving the strength and toughness of the self-fluxing cemented carbide spherical powder. In addition, the flux material can also improve the fluidity of the liquid phase during the sintering process, promote the uniform mixing and densification of the alloy, and is conducive to obtaining the self-fluxing cemented carbide spherical powder with uniform composition.

[0037] In some embodiments, the hard phase material includes at least one of WC, CrC, TiC, SiC, Al2O3, ZrO, AlN, TiN, TaN, BN, P3N5, Si3N4, and ZnB, and the above types of hard phase materials have high wear resistance and hardness.

[0038] In some embodiments, the particle size of the hard phase material is 100 mm to 200 mm.

[0039] In some embodiments, the bonding phase material includes at least one of Co, Ni, Fe, Cu, and Mo. The above types of bonding phase materials can enhance the bonding force between hard phase materials, improve the toughness and impact resistance of the alloy, and also improve the sphericity of the self-fluxing cemented carbide powder.

[0040] In some embodiments, the particle size of the binder phase material is 100 mm to 200 mm.

[0041] In some embodiments, the flux material includes B and Si. The above types of flux materials can inhibit the growth of grains, which is conducive to obtaining finer grains and improving the strength and toughness of the self-fluxing cemented carbide spherical powder. In addition, the flux material can also improve the fluidity of the liquid phase during the sintering process, promote the uniform mixing and densification of the alloy, and is conducive to obtaining a self-fluxing cemented carbide spherical powder with uniform composition.

[0042] In some embodiments, the flux material is B and Si, and the hard phase material includes WC and Co. In this embodiment, the flux material and the hard phase material are easy to mix evenly to obtain a uniformly mixed self-fluxing cemented carbide spherical powder, which is used to prepare cladding layer products. Material segregation is not likely to occur, and a uniform cladding layer product is easy to prepare, thereby improving the performance of the cladding layer product.

[0043] In some embodiments, the particle size of the flux is 100 mm to 200 mm.

[0044] In the present invention, the composition ratio of the hard phase material, the binder phase material and the flux material can be matched as required.

[0045] In some embodiments, based on the total mass of 100% of the hard phase material, the binder phase material, and the flux material, the weight percentage of the hard phase material is greater than or equal to 50%, which is beneficial to improving the hardness, wear resistance, compressive strength and thermal stability of the final product, the self-fluxing cemented carbide spherical powder, while obtaining better surface integrity and improving the sphericity rate. It is used as a raw material in laser cladding and plasma cladding processing, and it is easy to obtain a uniform cladding layer product.

[0046] In some embodiments, based on 100% of the total mass of the hard phase material, the binder phase material, and the flux material, the weight percentage of the flux material is less than or equal to 5%, which is beneficial to refine the grains and obtain grains with smaller particle size. At the same time, it improves the fluidity of the liquid phase during the sintering process, promotes the uniform mixing and densification of the alloy, and is beneficial to obtain self-fluxing cemented carbide spherical powder with uniform composition. It is used as a raw material in laser cladding and plasma cladding processing. It is not easy to produce material segregation during the cladding process, and it is easy to prepare a uniform cladding layer product.

[0047] The present invention mixes hard phase material, bonding phase material and flux material and then performs sintering, arc micro-explosion, reduction and screening treatments to obtain self-fluxing cemented carbide spherical powder with less surface oxides. The self-fluxing cemented carbide spherical powder is applied to cladding processing, material segregation is not likely to occur, and a cladding layer product with uniform composition can be prepared.

[0048] In some embodiments, the sintering temperature is 1400°C to 1500°C. Under the above temperature conditions, it is beneficial to promote the uniform mixing of hard phase materials, bonding phase materials, and flux materials to obtain a self-fluxing cemented carbide blank with uniform composition. The self-fluxing cemented carbide blank is subjected to arc micro-explosion, reduction, and screening treatment to obtain a self-soluble cemented carbide spherical powder with specific composition. The self-soluble cemented carbide spherical powder with specific composition is applied to laser cladding and plasma cladding processes. It is not easy to produce material segregation during the cladding process, and it is easy to prepare a uniform cladding layer product.

[0049] In some embodiments, the sintering time is greater than or equal to 6 hours, and can be 6 hours, 7 hours, 8 hours, etc.

[0050] In the present invention, in step S20, arc discharge is formed by applying current to form a molten pit on the surface of the self-fluxing cemented carbide, so as to facilitate the subsequent generation of small metal droplets by the impact of high-pressure fluid.

[0051] In some embodiments, before the operation of step S20 is performed, a step of cleaning and decontaminating the self-fluxing cemented carbide blank is also included. The specific cleaning and decontamination steps may be steps commonly used in the art, and will not be described in detail here.

[0052] In some embodiments, the discharge current is greater than or equal to 300 A, so that a molten pit is easily formed on the surface of the self-fluxing cemented carbide blank.

[0053] In some embodiments, the relative gap distance between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply is 0.03 mm to 0.05 mm. Within the above gap distance range, it is conducive to accurately controlling the formation of the molten pit, and the arc is relatively stable, making the formation and maintenance of the molten pit more controllable, and helping to avoid excessive expansion or instability of the molten pit, thereby improving the composition uniformity and sphericity of the self-fluxing cemented carbide spherical powder obtained subsequently.

[0054] In the present invention, step S30 uses high-pressure fluid to impact the molten pit, which can cause the molten pit to produce fine metal droplets. The metal droplets fly away from the molten zone and cool rapidly to obtain primary self-fluxing cemented carbide spherical powder.

[0055] In some embodiments, the high-pressure fluid includes high-pressure water flow and / or high-pressure gas. The high-pressure water flow and high-pressure gas impacting the molten pit can quickly cool the metal droplets, help form a fine grain structure, and improve the strength, toughness and sphericity of the material. In addition, the deposition position and shape of the small droplets can be precisely controlled by precisely controlling the parameters of the high-pressure water flow and high-pressure gas, and it is not easy to react with the components in the self-fluxing cemented carbide to cause the generation of impurities.

[0056] In some embodiments, the high-pressure fluid is a high-pressure gas, which includes high-pressure air, high-pressure nitrogen, high-pressure argon and / or high-pressure helium. The above types of high-pressure gases are not easy to react with the components in the self-fluxing cemented carbide to cause the generation of impurities.

[0057] In some embodiments, the high-pressure fluid is a high-pressure water flow, the applied pressure is 1MPa~2MPa, and the flow rate is 50L / min~60L / min, which can promote the dispersion of small metal droplets and prevent the small metal droplets from sticking together before cooling to form self-fluxing cemented carbide spherical powder, thereby improving the sphericity of the self-fluxing cemented carbide spherical powder and controlling it to obtain a smaller particle size.

[0058] In some embodiments, step S30 is performed in an inert gas environment, such as an argon or nitrogen atmosphere, which can reduce oxidation of the metal droplets during the cooling process and provide a more uniform cooling environment, thereby helping to improve the sphericity of the metal powder.

[0059] In some embodiments, by adjusting the relative horizontal movement of the negative electrode of the pulse power supply and the positive electrode of the pulse power supply, countless molten pits can be formed in sequence on the horizontal plane of the self-fluxing cemented carbide blank facing the electrode direction, and the flying material can be transformed into primary self-fluxing cemented carbide spherical powder. The material of a layer of the self-fluxing cemented carbide horizontal plane will be peeled off into countless initial self-fluxing cemented carbide spherical powders.

[0060] In some embodiments, the relative vertical movement of the negative electrode of the pulse power supply and the positive electrode of the pulse power supply can be adjusted so that the self-fluxing cemented carbide blank can be peeled off layer by layer into countless initial self-fluxing cemented carbide spherical powders until the entire self-fluxing cemented carbide blank is completely peeled off, thereby improving the utilization rate of the material.

[0061] In some embodiments, the electrode is fed horizontally at a speed of 600 mm / min relative to the self-fluxing cemented carbide, and is fed vertically at a speed of 0.5 mm / min.

[0062] In some embodiments, the primary self-fluxing cemented carbide spherical powder is washed before being processed in the subsequent step S40.

[0063] In some embodiments, the primary self-fluxing cemented carbide spherical powder is washed with an alcohol cleaning agent, such as ethanol.

[0064] In some embodiments, in step S40, the primary self-fluxing cemented carbide spherical powder is subjected to a reduction treatment in a hydrogen atmosphere, which makes it less likely for side reactions to occur and produce excessive impurities.

[0065] In some embodiments, the temperature range of the reduction treatment is 950°C to 1050°C.

[0066] In some embodiments, the reduction treatment time is 6 h to 8 h.

[0067] In some embodiments, the screening process includes an ultrasonic vibration screening process or an air flow classification screening process.

[0068] In some embodiments, the particle size of the self-fluxing cemented carbide spherical powder obtained by sieving is in the range of 50 μm to 150 μm.

[0069] The self-fluxing cemented carbide spherical powder of the present invention can be applied to cladding processing as a raw material for cladding processing, wherein the cladding processing includes plasma cladding processing and laser cladding processing.

[0070] The present invention also provides a cladding processing method, which includes the steps of the method for preparing the self-fluxing cemented carbide spherical powder of the present invention, and uses the prepared self-fluxing cemented carbide spherical powder as a raw material to prepare a cladding layer product through a cladding processing process. The cladding processing process includes a laser cladding process or a plasma cladding process, and the cladding layer product includes a cladding metal coating.

[0071] The cladding processing technology of the present invention can refer to the process flow and process parameters well known in the art, and use the self-fluxing cemented carbide blank of the present invention as the raw material in the cladding processing to perform cladding treatment. Because the self-fluxing cemented carbide blank is a mixture of different types of metal powders in advance according to a certain weight ratio, it is possible to customize the proportions at the stage of preparing the self-fluxing hard metal spherical powder according to the composition requirements of the cladding layer product, and then perform physical mixing during ball milling, chemical mixing during the sintering process, and finally undergo arc micro-explosion treatment to easily obtain self-fluxing cemented carbide spherical powder with uniform composition, high sphericity, lower cost and less surface oxides. The self-fluxing cemented carbide spherical powder is applied to cladding processing, material segregation is not likely to occur, and a cladding layer product with uniform composition can be prepared.

[0072] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0073] Example 1

[0074] The preparation method of the self-fluxing cemented carbide spherical powder of this embodiment is as follows:

[0075] S10. Place the hard phase material, the binder phase material and the flux material in a powder mixer and mix them evenly according to Table 1. Then place them in a ball mill and mix them thoroughly to obtain a mixed powder. Place the mixed powder in a vacuum sintering furnace and sinter at 1400° C. for 6 hours to form a self-fluxing cemented carbide blank.

[0076] S20, connect the self-fluxing cemented carbide blank to the positive electrode of the pulse power supply, connect the graphite electrode to the negative electrode of the pulse power supply, the relative gap distance between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply is 0.03mm, apply a current of 320A between the positive and negative electrodes, and arc discharge on the surface of the self-fluxing cemented carbide to form a molten pit on the surface of the self-fluxing cemented carbide.

[0077] S30. Introduce pure water high-pressure fluid between the positive electrode and the negative electrode of the pulse power supply, with a pressure of 1MPa and a flow rate of 50L / min. Locally strengthen the fluid to rush through the molten pit on the surface of the self-fluxing cemented carbide at high speed, causing the molten pit to explode and produce countless small droplets. The small droplets fly away from the molten zone and are cooled by an external low-temperature fluid to obtain primary self-fluxing cemented carbide spherical powder.

[0078] S40. The primary self-fluxing cemented carbide spherical powder is cleaned with ethanol, an alcohol cleaning agent, and then placed in a hydrogen atmosphere for reduction treatment. The reduction temperature is set to 950°C and the reduction time is 4 hours. The primary self-fluxing cemented carbide spherical powder that has completed the reduction treatment is placed on an air flow grading sieve for sieving to obtain three types of self-fluxing cemented carbide spherical powders with a particle size range of 50μm to 150μm, a particle size less than 50μm, and a particle size greater than 150μm.

[0079] Example 2

[0080] Example 2 Self-fluxing cemented carbide spherical powder was prepared by referring to the preparation method of Example 1, except that the composition of the self-fluxing cemented carbide was different, as shown in Table 1.

[0081] Example 3

[0082] Example 3 Self-fluxing cemented carbide spherical powder was prepared by referring to the preparation method of Example 1, except that the composition of the self-fluxing cemented carbide was different, as shown in Table 1.

[0083] Performance Testing

[0084] The self-fluxing cemented carbide spherical powder with a particle size of 50 μm to 150 μm obtained in Examples 1 to 3 was used as a raw material, and a FV520B steel plate was used as a substrate. A cladding alloy coating with a thickness of 5 nm was prepared on the surface of the steel plate using a plasma cladding process. The process parameters of the plasma cladding were as follows: argon gas with a purity of 99.99% was used as a protective gas, the current was set to 100 A, the voltage was set to 50 V, and the feed weight was set to 5.5 g / min. At the same time, a control group was set. The control group mixed 60% WC, 5% CrC and 30% Ni with a particle size of 50 μm to 150 μm by stirring, and then used as a raw material to prepare a cladding alloy coating on the surface of the FV520B steel plate using the same plasma cladding process parameters.

[0085] The cladding alloy coatings obtained in Examples 1 to 3 and the control group were subjected to a thermal shock test. Specifically, the substrate containing the cladding alloy coating was placed in a furnace and heated at 500°C for 10 minutes, and then placed in cold water at -20°C for 10 minutes. This was used as a test cycle. The cycle was repeated 150 times to observe whether the cladding alloy coating had fine cracks or cracking. The results are shown in Table 1.

[0086] Table 1

[0087]

[0088]

[0089] As can be seen from Table 1, the self-fluxing cemented carbide spherical powders of Examples 1 to 3 are used as raw materials, and the various materials in the self-fluxing cemented carbide spherical powders are mixed uniformly. The cladding alloy coating prepared by the plasma cladding process has good uniformity and good adhesion to the substrate. After the thermal shock test, the cladding alloy coating is intact without fine cracks and cracking.

[0090] The control group used alloy powder obtained by physical mixing of 60% WC, 5% CrC and 30% Ni as raw material. Because physical mixing is difficult to achieve uniform mixing, problems such as material segregation are prone to occur when preparing the cladding alloy coating, which will cause the prepared cladding alloy coating to also become uneven, thereby affecting the durability of the cladding alloy coating. Therefore, after the thermal shock test, the cladding alloy coating showed fine cracks.

[0091] It can be seen that the present invention compounds the hard phase material, the bonding phase material and the flux material, obtains the self-fluxing cemented carbide blank through sufficient ball milling mixing and sintering, and then prepares the self-fluxing soluble cemented carbide spherical powder through arc micro-explosion. The self-fluxing soluble cemented carbide spherical powder is used as the raw material in the cladding process. The cladding alloy coating obtained by the cladding process has uniform composition, strong bonding force and good durability. Moreover, according to the composition requirements of the cladding alloy coating, a customized ratio can be performed at the stage of preparing the self-fluxing hard metal spherical powder, thereby achieving the purpose of customized design.

[0092] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing self-fluxing cemented carbide spherical powder, characterized in that: The following steps are involved: S10, mixing and ball-milling the hard phase material, the binder phase material, and the flux material, and then sintering to obtain a self-fluxing cemented carbide blank; S20, connecting the self-fluxing cemented carbide blank to the positive electrode of a pulse power supply, connecting the graphite electrode to the negative electrode of the pulse power supply, applying a current between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply to form an arc discharge, and forming a molten pit on the surface of the self-fluxing cemented carbide blank; S30, introducing a high-pressure fluid between the positive electrode of the pulse power supply and the negative electrode of the pulse power supply, so that the high-pressure fluid rushes through the molten pit, prompting the molten pit to produce small droplets, and the small droplets are cooled to obtain primary self-fluxing cemented carbide spherical powder; S40, reducing and sieving the primary self-fluxing cemented carbide spherical powder to obtain self-fluxing cemented carbide spherical powder.

2. The method for preparing the self-fluxing cemented carbide spherical powder according to claim 1, characterized in that: The hard phase material includes at least one of WC, CrC, TiC, SiC, Al2O3, ZrO, AlN, TiN, TaN, BN, P3N5, Si3N4, and ZnB; And / or, the bonding phase material includes at least one of Co, Ni, Fe, Cu, and Mo; And / or, the flux material includes B and Si.

3. The method for preparing the self-fluxing cemented carbide spherical powder according to claim 1, characterized in that: Based on the total mass of the hard phase material, the binder phase material and the flux material being 100%, the weight percentage of the hard phase material is greater than or equal to 50%; and / or the weight percentage of the flux material is less than or equal to 5%.

4. The method for preparing the self-fluxing cemented carbide spherical powder according to claim 1, characterized in that: The sintering temperature is 1400° C. to 1500° C.; and / or the sintering time is greater than or equal to 6 hours.

5. The method for preparing the self-fluxing cemented carbide spherical powder according to claim 1, characterized in that: In the step S20, the applied current is above 300A.

6. The method for preparing the self-fluxing cemented carbide spherical powder according to claim 1, characterized in that: The high-pressure fluid includes high-pressure water flow and / or high-pressure gas.

7. The method for preparing the self-fluxing cemented carbide spherical powder according to claim 6, characterized in that: The high-pressure fluid is a high-pressure gas, and the high-pressure gas includes high-pressure air, high-pressure nitrogen, high-pressure argon and / or high-pressure helium.

8. The method for preparing the self-fluxing cemented carbide spherical powder according to claim 1, characterized in that: In the step S40, the primary self-fluxing cemented carbide spherical powder is subjected to a reduction treatment in a hydrogen atmosphere; and / or, the screening method includes an ultrasonic vibration screening treatment or an air flow classification screening treatment.

9. A self-fluxing cemented carbide spherical powder prepared by the method for preparing the self-fluxing cemented carbide spherical powder according to any one of claims 1 to 8.

10. Use of the self-fluxing cemented carbide spherical powder according to claim 9 in the field of cladding processing.

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