Wear-resistant composite material having a gradient structure and its manufacturing method

Abstract

The present invention relates to a wear-resistant composite material with a gradient structure and a method for producing the same. The method involves first vacuum-depositing a fine-grained wear-resistant powder onto the surfaces of coarse-grained wear-resistant particles, then uniformly mixing the resulting surface-modified coarse-grained wear-resistant particles with the fine-grained wear-resistant powder and a solvent containing a dispersant to obtain a composite slurry. The composite slurry is then poured into a mold placed on a vibration table, vibrated on the vibration table, and heated to remove the solvent. Finally, the mold is placed in a hot press for sintering to obtain a wear-resistant composite material with a gradient structure. The coarse-grained wear-resistant material is distributed in a gradient manner within the fine-grained wear-resistant material, and the material exhibits excellent strength, toughness, and wear resistance under operating conditions such as high-speed impact and long-term wear.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from Chinese invention patent application No. 202310292338.8, filed on March 23, 2023, with the invention title "Wear-resistant composite material with gradient structure and manufacturing method thereof."

[0002] Technical Field The present invention relates to the technical field of powder metallurgy, and more particularly to a wear-resistant composite material having a gradient structure and a method for manufacturing the same. [Background technology]

[0003] Cemented carbide is a composite material typically produced by powder metallurgy, using a refractory metal hard compound (e.g., WC or TiC) as the hard phase and a transition metal (e.g., Fe, Co, Ni and their alloys or high-entropy alloys) as the binder phase. Cemented carbide has extremely high hardness, strength, wear resistance, and corrosion resistance, and is widely used in fields such as defense, aerospace, machining, metallurgy, oil drilling, mining tools, electronics and communications, and construction.

[0004] However, cemented carbide is expensive and has poor impact resistance, and in order to further expand the application fields of cemented carbide, it is necessary to improve the impact resistance of cemented carbide.

[0005] Introducing a gradient structure is one method for modifying cemented carbide. For example, a Chinese patent (Publication No. 115725884A) discloses a high-cobalt YG cemented carbide with a gradient structure for use in forming dies and a manufacturing method thereof. In this method, a trace amount of TiN powder is added to the raw materials Co powder, W powder, and WC powder used to manufacture the high-cobalt YG cemented carbide. The TiN, as a second hard phase, improves the hardness and plastic deformation resistance of the high-cobalt YG cemented carbide. The strong thermodynamic bonding between Ti and N is utilized to obtain a cemented carbide with a gradient structure, allowing the surface layer of the cemented carbide to maintain a WC-Co two-phase structure and high toughness. The sintered gradient cemented carbide is then deep-chilled to compensate for the decrease in transverse fracture strength of the YG cemented carbide due to the introduction of TiN, thereby producing a high-cobalt YG cemented carbide with a gradient structure that is hard, highly resistant to plastic deformation, and strong. However, in the prior art, the gradient modification of cemented carbide is basically focused on the crystalline phase structure, and no modification is made to the impact resistance of the cemented carbide.

[0006] Furthermore, non-metallic wear-resistant materials such as alumina, silicon nitride, silicon carbide, boron carbide, and boron nitride have high strength, high hardness, high temperature resistance, and good wear resistance. These non-metallic wear-resistant materials face similar problems in industrial applications as cemented carbide materials. When used in large blocks, non-metallic wear-resistant materials are too brittle, have poor impact resistance, and are prone to breakage. Therefore, by combining non-metallic and metallic materials, the composite material can combine the impact resistance of the metallic material with the high strength, high temperature resistance, and wear resistance of the non-metallic material, thereby significantly improving material performance.

[0007] The composite of non-metallic and metallic materials has long been a challenging issue in the materials field, and in particular, the composite of wear-resistant non-metallic and wear-resistant metallic materials has not been widely reported. Summary of the Invention

[0008] In view of this, the present invention provides a wear-resistant composite material with a gradient structure and a manufacturing method thereof, in order to solve the technical problems of the relatively high price and poor impact resistance of cemented carbide in the prior art. During the research and development process, the inventors of the present application have found that this composite method is also applicable to non-metallic wear-resistant materials such as alumina, silicon nitride, silicon carbide, boron carbide, and boron nitride.

[0009] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0010] The present invention provides a method for manufacturing a wear-resistant composite material having a gradient structure, the method comprising the following steps: Step 1: Coarse-grained wear-resistant material particles and fine-grained wear-resistant material powder are uniformly mixed in a volume ratio of 1:100 to 10:1, and then vacuum-deposited to obtain surface-modified coarse-grained wear-resistant material particles; The coarse-grained wear-resistant particles are one type of cemented carbide particles or a mixture of multiple types of cemented carbide particles, or the coarse-grained wear-resistant particles are one type of non-metallic wear-resistant material or a mixture of multiple types of non-metallic wear-resistant materials, or the coarse-grained wear-resistant particles are a mixture of one or multiple types of the above cemented carbide particles and one or multiple types of non-metallic wear-resistant materials, and the coarse-grained wear-resistant particles are in a particle size range D 50 is 1 to 200 mm, The fine-grained wear-resistant material powder is an iron alloy powder, and the fine-grained wear-resistant material powder is within a particle size range D 50 is 0.1 to 200 μm. Step 2: The surface-modified coarse-grained wear-resistant material particles, the fine-grained wear-resistant material powder remaining in Step 1, and a solvent containing a dispersant are uniformly mixed to obtain a composite slurry. Step 3: Pour the composite slurry into a mold, vibrate the mold, and after the vibration is completed, heat it to remove the solvent in the composite slurry. The vibration conditions are a vibration frequency of 10 Hz to 5000 Hz and an acceleration of 1 m / s 2 ~1000m / s 2 , and the duration is 0.001 hours to 10 hours. Step 4: The mold is pressure-sintered to obtain a wear-resistant composite material with a gradient structure.

[0011] Preferably, in step 1, the coarse-grained wear-resistant material particles are a mixture of one or more of WC-based cemented carbide particles, TiC-based cemented carbide particles, TiCN-based cemented carbide particles, and TiN-based cemented carbide particles; or the coarse-grained wear-resistant material particles are a mixture of one or more of alumina, zirconia, silicon carbide, silicon nitride, boron carbide, and boron nitride; or the coarse-grained wear-resistant material particles are a mixture of one or more of the above cemented carbide particles and one or more of a non-metallic wear-resistant material selected from alumina, zirconia, silicon carbide, silicon nitride, boron carbide, and boron nitride.

[0012] Preferably, in step 1, the conditions for the vacuum deposition are a degree of vacuum of ≦−0.1 MPa, a temperature of 600 to 1200° C., and a time of 0.1 to 200 hours.

[0013] Preferably, in step 1, the iron alloy powder is high chromium cast iron powder, manganese steel alloy powder, ductile cast iron powder, high manganese steel powder, stainless steel powder, or a mixture of one or more of the above powders.

[0014] Preferably, in step 2, the solvent is ethanol.

[0015] Preferably, in step 2, the dispersant is a mixture of one or more of polyvinyl alcohol, polyethylene glycol, polyvinyl butyral ester, and stearic acid.

[0016] Preferably, in step 2, the amount of dispersant used is 0.001 wt.% to 10 wt.% of the mass of the fine-grained wear-resistant material powder in step 1, more preferably 0.01 wt.% to 1 wt.%, and particularly preferably 0.01 wt.% to 0.1 wt.%.

[0017] Preferably, in step 2, uniform mixing is achieved by drum wet milling. More preferably, the grinding balls used in drum wet milling are steel balls, cemented carbide balls, or ceramic balls. More preferably, the conditions for drum wet milling are a ball-to-charge ratio of 0.1:10 to 10:0.1, a ball milling time of 2 to 48 hours, a solid content of 10 vol.% to 80 vol.%, and the remainder being solvent.

[0018] Preferably, in step 3, the heating temperature is 30° C. to 150° C. and the heating time is 0.1 hours to 10 hours.

[0019] Preferably, in step 4, the pressure range is 0.1 MPa to 100 MPa, the temperature rise rate is 0.01°C / min to 30°C / min, the sintering temperature is 800°C to 1400°C, and the sintering time is 0.1 hour to 10 hours.

[0020] The present invention further provides a wear-resistant composite material having a gradient structure produced by the above-mentioned method for producing a wear-resistant composite material having a gradient structure.

[0021] The principle of the present invention is as follows. In the method for producing a wear-resistant composite material with a gradient structure of the present invention, a layer of fine-grained wear-resistant material powder is deposited on the surface of coarse-grained wear-resistant material particles. This reduces the potential difference between the coarse-grained wear-resistant material particles and the fine-grained wear-resistant material powder in the solvent when the two are mixed. Furthermore, this reduces the difference in sedimentation between the two, making the fine-grained powder less likely to settle to the bottom during the subsequent vibration process. This allows for the gradient structure to be tailored by taking advantage of the different performance behaviors of the surface-modified coarse-grained wear-resistant material particles and the fine-grained wear-resistant material powder in the mixed slurry under the same vibration conditions. Specifically, the higher the acceleration, the easier it is for the surface-modified coarse-grained wear-resistant material particles to move downward. The vibration frequency is suitable for controlling the gradient distribution of the coarse-grained wear-resistant material particles to better achieve surface modification. If a layer of fine-grained wear-resistant material powder is not deposited on the surface of the coarse-grained wear-resistant material particles, or if the acceleration and vibration frequency are not controlled, the fine-grained wear-resistant material powder will easily settle to the bottom, making it difficult to achieve a gradient distribution of the coarse-grained wear-resistant material particles. Furthermore, depositing a layer of fine-grained wear-resistant material powder on coarse-grained wear-resistant material particles is advantageous for sintering density in subsequent processes.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: The method for producing a wear-resistant composite material with a gradient structure of the present invention involves depositing a layer of fine-grained wear-resistant material powder on the surface of coarse-grained wear-resistant material particles to reduce the difference in sedimentation between the two, and then combining this with vibration to form a gradient distribution of the coarse-grained wear-resistant material. This method is simple to operate and suitable for mass production. The gradient distribution can be adjusted by adjusting parameters such as the mixing ratio of the surface-modified coarse-grained wear-resistant material particles to the fine-grained wear-resistant material powder, the vibration frequency, and the vibration time.

[0023] The wear-resistant composite material having a gradient structure produced by the present invention is composed of coarse-grained wear-resistant material particles with excellent hardness and wear resistance and fine-grained wear-resistant material powder with excellent impact toughness, with the coarse-grained wear-resistant material particles being distributed in a gradient manner within the fine-grained wear-resistant material powder, and the side of the composite with a higher proportion of coarse-grained wear-resistant material particles exhibits good wear resistance, while the side with a higher proportion of fine-grained wear-resistant material powder exhibits good impact resistance. The present invention realizes that the wear-resistant composite material can exhibit good strength, toughness, and wear resistance under working conditions such as high-speed impact and long-term wear, and is particularly suitable for working conditions requiring high wear resistance and impact toughness, such as ball mill linings, caterpillar track pins, and excavator bucket teeth.

[0024] In the following, in order to more clearly explain the technical solutions in the embodiments of the present invention, the accompanying drawings that need to be used in the embodiments will be briefly described. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and those skilled in the art can conceive of other accompanying drawings based on these accompanying drawings without any creative efforts. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a process flow diagram of a method for producing a wear-resistant composite material having a gradient structure according to the present invention. [Figure 2] 1 is a schematic diagram of a bottom cross section of a wear-resistant composite material having a gradient structure according to the present invention; [Figure 3] 1 is a schematic diagram of a longitudinal section of a wear-resistant composite material having a gradient structure according to the present invention. [Figure 4] 1 is a schematic diagram of a bottom cross section of a wear-resistant composite material having a gradient structure according to Example 1 of the present invention. [Figure 5] 1 is a schematic diagram of a longitudinal section of a wear-resistant composite material having a gradient structure according to Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] In order to provide a better understanding of the present invention, preferred embodiments of the present invention will be described below. It should be understood that these descriptions are merely to further illustrate the features and advantages of the present invention and are not intended to limit the scope of the claims of the present invention.

[0027] The method for producing a wear-resistant composite material having a gradient structure of the present invention includes the following steps. Step 1: Coarse-grained wear-resistant material particles and fine-grained wear-resistant material powder are uniformly mixed in a volume ratio of 1:100 to 10:1, and then vacuum-deposited to form a layer of fine-grained wear-resistant material powder on the surface of the coarse-grained wear-resistant material particles, thereby obtaining surface-modified coarse-grained wear-resistant material particles. Step 2: The surface-modified coarse-grained wear-resistant material particles, the fine-grained wear-resistant material powder remaining in Step 1, and a solvent containing a dispersant are uniformly mixed to obtain a composite slurry. Step 3: The composite slurry is poured into a mold, and the mold is vibrated to form a gradient distribution of surface-modified coarse-grained wear-resistant material particles. At the same time, the gas in the composite slurry is expelled, and the composite slurry is fully filled into the mold. Then, the mold is heated to remove the solvent. Step 4: The mold is pressure-sintered, and the surface-modified coarse-grained wear-resistant material particles and the fine-grained wear-resistant material powder are fully sintered and densified to form a metallurgical bond, thereby obtaining a wear-resistant composite material with a gradient structure.

[0028] In the above technical solution, in step 1, the coarse-grained wear-resistant material particles are a mixture of one type of cemented carbide particles or multiple types of cemented carbide particles. When a mixture of multiple types of cemented carbide particles is used, the mixing ratio is not particularly limited and can be set as needed. The coarse-grained wear-resistant material particles have good wear resistance and provide hardness and wear resistance to the composite material. Preferably, the coarse-grained wear-resistant material particles are a mixture of one or more types of WC-based cemented carbide particles, TiC-based cemented carbide particles, TiCN-based cemented carbide particles, and TiN-based cemented carbide particles mixed in any ratio, and more preferably, YG6 cemented carbide particles, YG8 cemented carbide particles, YT15 cemented carbide particles, or YW1 cemented carbide particles.

[0029] Alternatively, the coarse-grained wear-resistant material particles may be a mixture of one or more of alumina, zirconia, silicon carbide, silicon nitride, boron carbide, and boron nitride, or the coarse-grained wear-resistant material particles may be a mixture of one or more of the above cemented carbide particles and one or more of a non-metallic wear-resistant material selected from alumina, zirconia, silicon carbide, silicon nitride, boron carbide, and boron nitride.

[0030] Other cemented carbide particles well known to those skilled in the art are also suitable for the present invention, and any material that has two or more of the following properties can be used as the coarse-grained wear-resistant particles: high strength, high hardness, high temperature resistance, and good wear resistance. The coarse-grained wear-resistant particles are millimeter-scale particles with a particle size range D50 of 1 to 200 mm, preferably 8 to 15 mm, and more preferably 8 to 10 mm.

[0031] In the above technical solution, in step 1, the fine-grained wear-resistant material powder is an iron alloy powder or other alloy powder, preferably a manganese steel alloy powder such as manganese steel MN600, manganese steel MN400, 316L, or QT900-2. Preferably, the fine-grained wear-resistant material matches the material of the substrate to which it is pre-bonded. For example, if the wear-resistant material of the present invention is pre-bonded with high-chromium cast iron or low-carbon steel, the iron alloy powder is selected to be high-chromium cast iron powder or low-carbon steel powder, or a material powder that is easy to bond with the substrate powder.

[0032] The fine-grained wear-resistant powder has good impact resistance and provides impact toughness to the composite material. The fine-grained wear-resistant powder is a micron-scale powder with a particle size range of D. 50 is 0.1 to 200 μm, preferably 50 to 100 μm, and more preferably 50 to 80 μm.

[0033] In the above technical solution, in step 1, a layer of fine-grained wear-resistant material powder is deposited on the surface of the coarse-grained wear-resistant material particles. This ensures that the potentials of the coarse-grained wear-resistant material particles and the fine-grained wear-resistant material powder in the solvent are close to each other when they are mixed, and further reduces the difference in sedimentation between them. The volume ratio of the coarse-grained wear-resistant material particles to the fine-grained wear-resistant material powder is preferably 1:2 to 1:4, and more preferably 1:3.

[0034] In the above technical solution, in step 1, vacuum deposition is typically carried out in a vacuum tank. The vacuum deposition conditions are preferably a degree of vacuum of ≦−0.1 MPa, a temperature of 600-1200°C, and a time of 0.1-200 hours. It is sufficient to deposit a layer of fine-grained wear-resistant material powder on the surface of coarse-grained wear-resistant material particles, and those skilled in the art may adopt other vacuum deposition conditions that can achieve this effect.

[0035] In the above technical solution, the solvent in step 2 is not particularly limited as long as it can disperse the dispersant, the surface-modified coarse wear-resistant material particles, and the fine wear-resistant material powder, and is preferably ethanol. Those skilled in the art can also select other solvents that can achieve the above functions as needed.

[0036] In the above technical solution, in step 2, the materials are uniformly mixed by drum wet milling. Preferably, the grinding balls used in drum wet milling are steel balls, cemented carbide balls, or ceramic balls. The ball-to-charge ratio is 0.1:10 to 10:0.1, preferably 1 to 2:1, and more preferably 1.5:1. The ball milling time is 2 to 48 hours, preferably 1.5 to 6 hours, and more preferably 3 to 4 hours. The solids content is 10% to 80% by volume, preferably 20% to 30% by volume, and more preferably 25% by volume. Other uniform mixing methods known to those skilled in the art can also be used.

[0037] In the above technical solution, the dispersant in step 2 is a common auxiliary agent used in the art, and serves to promote dispersion. In this embodiment, the dispersant is preferably one or a mixture of polyvinyl alcohol, polyethylene glycol, polyvinyl butyral ester, and stearic acid. When a mixture of multiple dispersants is used, the mixing ratio is not particularly limited and can be set as needed. The amount of dispersant used is 0.001 wt.% to 10 wt.% of the mass of the fine-grained wear-resistant material powder in step 1, preferably 0.01 wt.% to 1 wt.%, and more preferably 0.01 wt.% to 0.1 wt.%.

[0038] In the above technical solution, in step 3, vibration is usually achieved by placing the mold on a vibration table. The vibration frequency is 10Hz to 5000Hz, preferably 30Hz to 200Hz, more preferably 50Hz to 100Hz, and the acceleration is 1m / s 2 ~1000m / s 2 and preferably 80 m / s 2 ~200m / s 2 and more preferably 100 m / s 2 ~200m / s 2 and the duration is 0.001 to 10 hours, preferably 0.01 to 0.5 hours, and more preferably 0.1 to 0.5 hours. Vibration is the core inventive feature of the present invention, and can achieve a gradient distribution of surface-modified cemented carbide particles or non-metallic material particles in the fine-grained wear-resistant material powder (i.e., the distribution number of cemented carbide particles or non-metallic material particles forms a gradient, with the density gradually increasing from top to bottom). The gradient distribution can be adjusted by adjusting parameters such as the blending ratio of the surface-modified coarse-grained wear-resistant material particles to the fine-grained wear-resistant material powder, the vibration frequency, and the vibration time.

[0039] In the above technical solution, in step 3, the heating temperature is preferably 30°C to 150°C, more preferably 70°C to 80°C, and the heating time is preferably 0.1 hours to 10 hours, more preferably 1 hour to 4 hours, and particularly preferably 2 hours to 3 hours. The heating device is usually a ventilation drying box. However, other heating devices known to those skilled in the art are also suitable for the present invention.

[0040] In the above technical proposal, in step 4, the pressure range is preferably 0.1 MPa to 100 MPa, more preferably 10 to 30 MPa, and particularly preferably 12 MPa. The temperature rise rate is preferably 0.01°C / min to 30°C / min, more preferably 5°C / min to 12°C / min, and particularly preferably 8°C / min to 12°C / min. The sintering temperature is determined depending on the material and is preferably 800°C to 1400°C. The sintering time is preferably 0.1 hours to 10 hours, and more preferably 1 to 2 hours. A press is usually selected as the apparatus for pressure-sintering the mold. However, other pressure-sintering apparatuses known to those skilled in the art are also suitable for the present invention.

[0041] As shown in Figures 2 and 3, the gradient-structure wear-resistant composite material produced by the method of the present invention is composed of coarse-grained wear-resistant material particles with excellent hardness and wear resistance and fine-grained wear-resistant material powder with excellent impact toughness. The coarse-grained wear-resistant material particles are distributed in a gradient manner within the fine-grained wear-resistant material powder. The side of the composite with a higher proportion of coarse-grained wear-resistant material particles exhibits good wear resistance, while the side with a higher proportion of fine-grained wear-resistant material powder exhibits good impact resistance. This composite material is particularly suitable for applications requiring high wear resistance and impact toughness, such as ball mill linings, caterpillar track pins, and excavator bucket teeth.

[0042] The terms used in the present invention generally have the meanings commonly understood by those skilled in the art unless otherwise specified. In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in connection with examples.

[0043] In the following examples, various processes and methods not described in detail are conventional methods known in the art. All materials, reagents, devices, instruments, equipment, etc. used in the following examples are commercially available unless otherwise specified.

[0044] The present invention will now be further described with reference to the following examples. [Example]

[0045] 5 kg of YG6 cemented carbide particles (D 50 15mm) and 10kg of manganese steel NM600 powder (D 50 After weighing and mixing, the mixture is placed in a vacuum tank, evacuated to -0.01 MPa (below -0.1 MPa), and vapor deposition is carried out at 800°C for 2 hours to deposit a layer of manganese steel NM600 powder on the surface of the YG6 cemented carbide particles, thereby obtaining surface-modified YG6 cemented carbide particles.

[0046] After cooling to room temperature, the surface-modified YG6 cemented carbide particles and the remaining manganese steel NM600 powder from step 1 were added to an ethanol solution containing a dispersant (stearic acid, 0.01 wt.% of the weight of 10 kg of manganese steel NM600 powder). The mixture was then uniformly mixed using a drum wet milling method and ball milled for 3 hours to obtain a composite slurry. The grinding balls used were YG6 cemented carbide balls, with a ball-to-charge ratio of 1:1 and a solids content of 20 vol.%.

[0047] The composite slurry was poured into a mold placed on a vibration table, and the mold was filled with the slurry by vibration, causing the surface-modified YG6 cemented carbide particles to settle and form a gradient distribution. The vibration table parameters were vibration frequency of 100Hz and acceleration of 100m / s. 2 The duration is 0.01 hours. Then, the mold is placed in a fan oven at 80°C and baked for 2 hours to remove the solvent.

[0048] Finally, the mold is placed in a hot press and pressurized to 10 MPa while the temperature is increased to 1100°C at a rate of 5°C / min and kept at that temperature for 2 hours. This sinters and densifies the surface-modified YG6 cemented carbide particles and manganese steel NM600 powder to produce a powder / particle wear-resistant material with a gradient structure.

[0049] The hardness, impact toughness and wear resistance of the powder / particle wear-resistant material with gradient structure manufactured in this example were tested. The hardness test standard was GB / T 230.1-2018, the impact toughness test standard was GB / T 229-2020, and the wear resistance test standard was GB / T 34501-2017. The test results showed that the hardness of the wear-resistant material was 49.9HRC and the impact toughness was 4.2J / cm 2 and the abrasive wear is 1.1 g / 10 min.

[0050] The powder / particle wear-resistant material with a gradient structure produced in this example was cut longitudinally and crosswise at the bottom, and the results are shown in Figures 5 and 4. Figures 5 and 4 show that in the powder / particle wear-resistant material produced in Example 1, the coarse-grained wear-resistant material particles are distributed in a gradient fashion within the fine-grained wear-resistant material powder. [Example]

[0051] 5 kg of YG8 cemented carbide particles (D 50 13mm) and 15kg of manganese steel NM400 powder (D 50 After weighing and mixing, the mixture is placed in a vacuum tank, evacuated to -0.01 MPa (below -0.1 MPa), and vapor deposition is carried out at a temperature of 720°C for 1.5 hours to vapor-deposit a layer of manganese steel NM400 powder onto the surface of the YG8 cemented carbide particles, thereby obtaining surface-modified YG8 cemented carbide particles.

[0052] After cooling to room temperature, the surface-modified YG8 cemented carbide particles and the manganese steel NM400 powder remaining from step 1 were added to an ethanol solution containing a dispersant (polyvinyl alcohol, 0.05 wt.% of the weight of 15 kg of manganese steel NM600 powder). The mixture was uniformly mixed by drum wet grinding and then ball milled for 6 hours to obtain a composite slurry. Here, the grinding balls used were steel balls, the ball-to-charge ratio was 1.5:1, and the solid content was 20 vol.%.

[0053] The composite slurry was poured into a mold placed on a vibration table, and the mold was filled with the slurry by vibration, causing the surface-modified YG8 cemented carbide particles to settle and form a gradient distribution. The vibration table parameters were vibration frequency 200Hz, acceleration 200m / s 2 The duration is 0.01 hours. Then, the mold is placed in a fan oven at 80°C and baked for 3 hours to remove the solvent.

[0054] Finally, the mold is placed in a hot press, and while applying a pressure of 30 MPa, the temperature is increased to 1100°C at a rate of 12°C / min and kept at that temperature for 2 hours. The surface-modified YG8 cemented carbide particles and manganese steel NM400 powder are sintered and densified to produce a powder / particle wear-resistant material with a gradient structure. Testing revealed that the wear-resistant material had a hardness of 57.4 HRC and an impact toughness of 5.1 J / cm. 2 The abrasive wear rate is 1.1 g / 10 min, and the coarse wear-resistant material particles are distributed in a gradient manner in the fine wear-resistant material powder. The test criteria are the same as those in Example 1. [Example]

[0055] 4 kg of YT15 cemented carbide particles (D 50 10mm) and 16Kg of 316L powder (D 50 After weighing and mixing, the mixture is placed in a vacuum tank, evacuated to -0.01 MPa (below -0.1 MPa), and evaporated at a temperature of 850°C for 1.5 hours to deposit a layer of 316L powder on the surface of the YT15 cemented carbide particles, thereby obtaining surface-modified YT15 cemented carbide particles.

[0056] After cooling to room temperature, the surface-modified YT15 cemented carbide particles and the remaining 316L powder from step 1 were added to an ethanol solution containing a dispersant (polyethylene glycol, 0.06 wt.% of the weight of 16 kg of manganese steel NM600 powder). The mixture was then uniformly mixed using a drum wet milling method and ball milled for 4 hours to obtain a composite slurry. The grinding balls used were YT15 cemented carbide balls, the ball-to-charge ratio was 1:1, and the solid content was 30 vol.%.

[0057] The composite slurry was poured into a mold placed on a vibration table, and the mold was filled with the slurry by vibration, causing the surface-modified YT15 cemented carbide particles to settle and form a gradient distribution. The vibration table parameters were vibration frequency of 50Hz and acceleration of 80m / s. 2 The duration is 0.5 hours. Then, the mold is placed in a 70°C fan oven and baked for 1 hour to remove the solvent.

[0058] Finally, the mold is placed in a hot press, and while applying a pressure of 12 MPa, the temperature is increased to 1350°C at a rate of 10°C / min, and then kept at that temperature for 1 hour. The surface-modified YT15 cemented carbide particles and 316L powder are sintered and densified to form a powder / particle wear-resistant material with a gradient structure. Test results show that the wear-resistant material has a hardness of 53.2HRC and an impact toughness of 4.2J / cm. 2 The abrasive wear rate is 1.4 g / 10 min, and the coarse wear-resistant material particles are distributed in a gradient manner in the fine wear-resistant material powder. The test criteria are the same as those in Example 1. [Example]

[0059] 10 kg of YW1 cemented carbide particles (D 50 8mm) and 20kg of QT900-2 powder (D 50 After weighing and mixing, the mixture is placed in a vacuum tank, evacuated to -0.01 MPa (below -0.1 MPa), and vapor deposition is carried out at a temperature of 650°C for 4 hours to vapor-deposit a layer of QT900-2 on the surface of the YW1 cemented carbide particles, thereby obtaining surface-modified YW1 cemented carbide particles.

[0060] After cooling to room temperature, the surface-modified YW1 cemented carbide particles and the remaining QT900-2 powder from Step 1 were added to an ethanol solution containing a dispersant (polyvinyl butyral ester, 0.05 wt.% of the weight of 20 kg of manganese steel NM600 powder). The mixture was then uniformly mixed using a drum wet milling method and ball milled for 1.5 hours to obtain a composite slurry. The grinding balls used were cemented carbide balls, with a ball-to-charge ratio of 2:1 and a solids content of 25 vol.%.

[0061] The composite slurry was poured into a mold placed on a vibration table, and the mold was filled with the slurry by vibration, causing the surface-modified YW1 cemented carbide particles to settle and form a gradient distribution. The vibration table parameters were vibration frequency of 30Hz and acceleration of 80m / s. 2 The duration is 0.1 hours. Then, the mold is placed in a 70°C fan oven and baked for 4 hours to remove the solvent.

[0062] Finally, the mold is placed in a hot press, and while applying a pressure of 12 MPa, the temperature is increased to 1000°C at a rate of 8°C / min and kept at that temperature for 1 hour. This sintering and densifying process densifies the surface-modified YW1 cemented carbide particles and QT900-2 powder into a powder / particle wear-resistant material with a gradient structure. Testing revealed that the wear-resistant material had a hardness of 58.3 HRC and an impact toughness of 5.1 J / cm. 2 The abrasive wear rate is 1.3 g / 10 min, and the coarse wear-resistant material particles are distributed in a gradient manner in the fine wear-resistant material powder. The test criteria are the same as those in Example 1. [Example]

[0063] 5 kg of silicon carbide particles (D 50 10mm) and 15kg of high chromium cast iron Cr15Mo3 powder (D 50 After weighing and mixing the silicon carbide particles (50 μm), the particles are placed in a vacuum tank, evacuated to -0.01 MPa (-0.1 MPa or less), and vapor deposition is carried out at a temperature of 500°C for 6 hours to vapor-deposit a layer of high-chromium cast iron Cr15Mo3 onto the surface of the silicon carbide particles, thereby obtaining surface-modified silicon carbide particles.

[0064] After cooling to room temperature, the surface-modified silicon carbide particles and the Cr remaining from step 1 were placed in an ethanol solution containing a dispersant (polyvinyl butyral ester, 0.1 wt.% of the weight of 15 kg of high-chromium cast iron Cr15Mo3 powder). 15 Add Mo3 powder, mix uniformly by drum wet grinding, and ball mill for 4 hours to obtain a composite slurry. The grinding balls used were cemented carbide balls, the ball-to-charge ratio was 1:1, and the solid content was 20 vol.%.

[0065] The composite slurry is poured into a mold placed on a vibration table, and the mold is filled with the slurry by vibration, causing the surface-modified silicon carbide particles to settle and form a gradient distribution. The vibration table parameters are a vibration frequency of 30 Hz and an acceleration of 150 m / s. 2 The duration is 0.05 hours. Then, the mold is placed in a fan oven at 80°C and baked for 3 hours to remove the solvent.

[0066] Finally, the mold is placed in a hot press, and while applying a pressure of 20 MPa, the temperature is increased to 1200°C at a rate of 10°C / min and maintained at that temperature for 0.5 hours. This sintering and densifying process densifies the surface-modified silicon carbide particles and Cr15Mo3 powder into a powder / particle wear-resistant material with a gradient structure. Testing revealed that the wear-resistant material had a hardness of 70.1 HRC and an impact toughness of 4.8 J / cm. 2 The abrasive wear rate is 1 g / 10 min, and the coarse wear-resistant material particles are distributed in a gradient manner in the fine wear-resistant material powder. The test criteria are the same as those in Example 1. [Example]

[0067] 3 kg of zirconia particles (D 50 10mm) and 20kg of high chromium cast iron Cr29 powder (D 50 After weighing and mixing the zirconia particles (30 μm), the mixture is placed in a vacuum tank, evacuated to -0.01 MPa (below -0.1 MPa), and vapor deposition is carried out at a temperature of 800°C for 1 hour to vapor-deposit a layer of high-chromium cast iron Cr29 onto the surface of the zirconia particles, thereby obtaining surface-modified zirconia particles.

[0068] After cooling to room temperature, the surface-modified zirconia particles and the remaining Cr29 powder from Step 1 were added to an ethanol solution containing a dispersant (polyvinyl butyral ester, 0.08 wt.% of the weight of 20 kg of high-chromium cast iron Cr29 powder). The mixture was uniformly mixed by drum wet milling and then ball milled for 4 hours to obtain a composite slurry. The abrasive balls used were zirconia balls, with a ball-to-charge ratio of 3:1 and a solids content of 22 vol.%.

[0069] The composite slurry was poured into a mold placed on a vibration table, and the mold was filled with the slurry by vibration, causing the surface-modified zirconia particles to settle and form a gradient distribution. The vibration table parameters were a vibration frequency of 40 Hz and an acceleration of 160 m / s. 2 The duration is 0.1 hours. Then, the mold is placed in a ventilated oven at 75°C and baked for 4 hours to remove the solvent.

[0070] Finally, the mold is placed in a hot press, and while applying a pressure of 26 MPa, the temperature is increased to 1200°C at a rate of 5°C / min and maintained at that temperature for 2 hours. This sintering and densifying process densifies the surface-modified zirconia particles and Cr29 powder to produce a powder / particle wear-resistant material with a gradient structure. Testing revealed that the wear-resistant material had a hardness of 78.2 HRC and an impact toughness of 5.9 J / cm. 2 The abrasive wear rate is 1.4 g / 10 min, and the coarse wear-resistant material particles are distributed in a gradient manner in the fine wear-resistant material powder. The test criteria are the same as those in Example 1.

[0071] Obviously, the above embodiments are merely for clarifying the examples given, and are not intended to limit the examples. Those skilled in the art can make various other modifications or changes based on the above description. It is not necessary and impossible to cover all the examples in this specification. Any obvious modifications or changes derived therefrom still fall within the protection scope of the present invention.

Claims

1. Step 1: uniformly mixing coarse wear-resistant material particles and fine wear-resistant material powder in a volume ratio of 1:100 to 10:1, and vacuum-depositing the mixture to obtain surface-modified coarse wear-resistant material particles; The coarse-grained wear-resistant material particles are one type of cemented carbide particles or a mixture of multiple types of cemented carbide particles, and the coarse-grained wear-resistant material particles are within the particle size range D ５０ is 1 to 200 mm, The fine-grained wear-resistant material powder is an iron alloy powder or a manganese steel alloy powder, and the fine-grained wear-resistant material powder falls within the particle size range D ５０ Step 1, wherein the thickness is 0.1 to 200 μm; Step 2: uniformly mixing the surface-modified coarse-grained wear-resistant material particles, the fine-grained wear-resistant material powder remaining in Step 1, and a solvent containing a dispersant to obtain a composite slurry; Step 3: pouring the composite slurry into a mold, vibrating the mold, and, after the vibration is completed, heating the mold to remove the solvent in the composite slurry; The vibration conditions are a vibration frequency of 10 Hz to 5000 Hz and an acceleration of 1 m / s ２ ~1000 m / s ２ ,Step 3, the duration is 0.001 hours to 10 hours; Step 4: Pressurizing and sintering the mold to obtain a wear-resistant composite material with a gradient structure; A method for producing a wear-resistant composite material having a gradient structure, comprising:

2. 2. The method for producing a wear-resistant composite material with a gradient structure according to claim 1, wherein in step 1, the coarse-grained wear-resistant material particles are one or a mixture of plural kinds of WC-based cemented carbide particles, TiC-based cemented carbide particles, TiCN-based cemented carbide particles, and TiN-based cemented carbide particles.

3. 2. The method for producing a wear-resistant composite material having a gradient structure according to claim 1, wherein the coarse-grained wear-resistant material particles are a mixture of one or more of alumina, zirconia, silicon carbide, and silicon nitride, or the coarse-grained wear-resistant material particles are a mixture of one or more of the above cemented carbide particles and one or more of a non-metallic wear-resistant material selected from alumina, zirconia, silicon carbide, silicon nitride, boron carbide, and boron nitride.

4. 2. The method for producing a wear-resistant composite material with a gradient structure according to claim 1, wherein in step 1, the vacuum deposition conditions are: a degree of vacuum of ≦−0.1 MPa, a temperature of 600 to 1200°C, and a time of 0.1 to 200 hours.

5. 2. The method for producing a wear-resistant composite material having a gradient structure according to claim 1, wherein the iron alloy powder is high chromium cast iron powder, manganese steel alloy powder, ductile cast iron powder, high manganese steel powder, stainless steel, or a mixture of one or more of the above powders.

6. 2. The method for producing a wear-resistant composite material with a gradient structure according to claim 1, wherein in step 2, the solvent is ethanol, the dispersant in step 2 is a mixture of one or more of polyvinyl alcohol, polyethylene glycol, polyvinyl butyral ester, and stearic acid, and the amount of the dispersant used is 0.001 wt. % to 10 wt. % of the mass of the fine-grained wear-resistant material powder in step 1.

7. 2. The method for producing a wear-resistant composite material with a gradient structure according to claim 1, wherein in step 2, uniform mixing is achieved by drum wet milling, the grinding balls used in drum wet milling are steel balls, cemented carbide balls or ceramic balls, and the conditions for drum wet milling are a ball-to-charge ratio of 0.1:10 to 10:0.1, a ball milling time of 2 to 48 hours, and a solid content of 10 vol.% to 80 vol.%.

8. 2. The method for producing a wear-resistant composite material with a gradient structure according to claim 1, wherein in step 3, the heating temperature is 30°C to 150°C, and the heating time is 0.1 hours to 10 hours.

9. 2. The method for manufacturing a wear-resistant composite material with a gradient structure according to claim 1, wherein in step 4, the pressure ranges from 0.1 MPa to 100 MPa, the heating rate is from 0.01°C / min to 30°C / min, the sintering temperature is from 800°C to 1400°C, and the sintering time is from 0.1 hours to 10 hours.

10. A wear-resistant composite material having a gradient structure, produced by the method for producing a wear-resistant composite material having a gradient structure according to any one of claims 1 to 9.

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