Al2O3-ZrO2 multiphase ceramic particles, their preparation method and application

Abstract

This invention discloses an Al2O3-ZrO2 multiphase ceramic particle, its preparation method, and its application, relating to the field of ceramic composite material preparation technology. The Al2O3-ZrO2 multiphase ceramic particle comprises Al2O3 / ZrO2 ceramic particles and multiple macroscopic pits formed on the surface of the Al2O3 / ZrO2 ceramic particles. The maximum projected size of the pit is 0.3 mm, and the maximum height difference between the pit and the surface is 0.3 mm. The Al2O3-ZrO2 multiphase ceramic particle provided in this application has a certain surface roughness, and its shape and structure are controllable. The surface is crack-free, which is beneficial for improving the wear resistance of composite materials in subsequent applications as reinforcing materials for steel. Simultaneously, it enables low-cost preparation of composite materials, achieving a significant increase in wear resistance.

Description

Technical Field

[0001] This invention relates to the field of ceramic composite material preparation technology, and more specifically, to an Al2O3-ZrO2 multiphase ceramic particle, its preparation method, and its application. Background Technology

[0002] Al2O3 / ZrO2 ceramic particles possess high strength and toughness, high hardness, high wear resistance, and a wide coefficient of thermal expansion, making them commonly used as reinforcing materials for metals, especially in steels such as high-chromium cast iron, high-manganese steel, and alloy steel to improve their wear resistance. Currently, Al2O3 / ZrO2 ceramic particles are prepared using electrofusion water explosion and powder metallurgy crushing methods. While these methods result in ceramic particles with a certain surface roughness and good hold on metal materials, they inevitably suffer from problems such as cracks, uncontrollable shape, and uncontrollable microstructure.

[0003] Among these issues, the presence of cracks in ceramic particles can lead to their continuous propagation during wear; uncontrollable shape results in significant differences in the size and morphology of the pores in the preforms made from ceramic particles; during the casting and infiltration process of composite materials, the molten steel flows unstablely through the pores between ceramic particles, leading to defects such as porosity and looseness in the composite material; and the uncontrollable microstructure is mainly reflected in the fact that Al2O3 / ZrO2 ceramics contain three phases of ZrO2, namely cubic, monoclinic, and tetragonal phases. When ZrO2 is tetragonal, it exhibits good strength, toughness, and wear resistance during service. However, in reality, the phase composition of ceramic particles is uncontrollable, resulting in significant differences in performance even for ceramics with the same composition.

[0004] In summary, due to the aforementioned defects in existing ceramics, the advantages of ceramic particle composites, especially their improved wear resistance, cannot be fully realized. This results in composite materials failing to achieve ideal performance or premature failure due to cracking and peeling of the composite layer. Furthermore, the traditional preparation process for wear-resistant composite materials using Al2O3 / ZrO2 ceramic particles involves: sintering the ceramic particles, activating the ceramic particles, coating the activated ceramic particles with a binder, sintering them into a framework, casting the framework into a mold to pour molten wear-resistant steel, and then solidifying and cooling to obtain the composite material. In this process, both the ceramic particle and framework preparation rely on sintering, thus resulting in high composite material preparation costs.

[0005] Therefore, the invention of ceramic particles with a certain surface roughness, no cracks, relatively regular shape, and controllable structure for use as reinforcing materials for steel materials, and the preparation of composite materials with short flow length and low cost, is of great significance for achieving high performance and low cost of wear-resistant composite materials.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide Al2O3-ZrO2 multiphase ceramic particles, their preparation method, and their applications.

[0008] This invention is implemented as follows:

[0009] In a first aspect, the present invention provides an Al2O3-ZrO2 multiphase ceramic particle, comprising Al2O3 / ZrO2 ceramic particles and a plurality of macroscopic pits formed on the surface of the Al2O3 / ZrO2 ceramic particles, wherein the maximum projected size of the pit is 0.3 mm and the maximum height difference between the pit and the surface is 0.3 mm.

[0010] In an optional embodiment, the ZrO2 phase in the Al2O3-ZrO2 multiphase ceramic particles is a mixture of tetragonal and monoclinic phases, with the tetragonal phase accounting for no less than 60%.

[0011] In an optional embodiment, the Al2O3 / ZrO2 ceramic particles comprise, by weight percentage, 20-78% Al2O3, 20-78% ZrO2, 1-3% stabilizer, 0.1-0.5% binder, and 0.1-0.5% dispersant.

[0012] In an optional embodiment, the particle size of both Al2O3 and ZrO2 is 100nm-500nm;

[0013] Preferably, the stabilizer is at least one selected from TiO2, Y2O3, MgO and CaO;

[0014] Preferably, the binder is at least one selected from zinc stearate, resin, and paraffin powder;

[0015] Preferably, the dispersant is at least one of water, alcohol, and acetone.

[0016] In a second aspect, the present invention provides a method for preparing Al2O3-ZrO2 multiphase ceramic particles, comprising: mixing and granulating the components of the Al2O3 / ZrO2 ceramic particles to obtain an Al2O3 / ZrO2 ceramic particle mixture;

[0017] The Al2O3 / ZrO2 ceramic particle mixture is formed into a quantitative dense mixture preform by centrifugal rotation, rolling, molding, extrusion or injection molding; the quantitative dense mixture preform is then rolled by roller pressing to form multiple macroscopic pits.

[0018] In an optional embodiment, the roll forming is performed using a roller device consisting of a first roller and a second roller in parallel contact. A storage hopper for placing a quantitative dense mixture blank is provided above the space between the first roller and the second roller. Both the first roller and the second roller are machined with multiple forming countersunk holes for forming pits. The roll forming method includes: when the first roller and the second roller are running in opposite directions, the quantitative dense mixture blank in the storage hopper enters between the first roller and the second roller and enters into two corresponding forming countersunk holes. The first roller and the second roller rotate in opposite directions, and the two corresponding forming countersunk holes close and compact, forming ceramic particles with pits.

[0019] Preferably, the shape of the formed countersunk hole is spherical, elliptical, or polygonal.

[0020] Thirdly, the present invention provides a method for preparing a wear-resistant reinforced composite material, comprising:

[0021] Nickel-containing alloy powder is coated onto the surface of Al2O3-ZrO2 multiphase ceramic particles as described in any of the above embodiments to form a wear-resistant material reinforcement.

[0022] The wear-resistant material reinforcement is placed in a mold and pressed to form a frame blank with multi-scale interconnected channels;

[0023] The ceramic particle framework is obtained by drying, sintering and cooling the initial framework blank.

[0024] The ceramic particle framework is placed in a mold, and the melt of the wear-resistant material matrix is ​​poured in. After solidification and cooling, a wear-resistant reinforced composite material is obtained.

[0025] In an optional embodiment, the mass ratio of the nickel-containing alloy powder to the Al2O3-ZrO2 multiphase ceramic particles is 10-20:90-80;

[0026] Preferably, the particle size of the nickel-containing alloy powder is 1-5 μm;

[0027] Preferably, the drying process includes drying at a temperature of 50-80°C for 5-10 hours;

[0028] Preferably, the sintering includes: heating to 1450-1550°C at a heating rate of no more than 80°C / h, and sintering for 6-10 hours;

[0029] Preferably, the cooling includes: cooling to 1100-1190°C at a cooling rate of 50-60°C / min and holding at that temperature for 1-3 hours, followed by air cooling to room temperature, wherein the tetragonal ZrO2 phase content accounts for not less than 60% of the ZrO2 phase.

[0030] In an optional embodiment, the mass ratio of the ceramic particle framework to the wear-resistant material matrix is ​​30-60:70-40;

[0031] Preferably, the wear-resistant material matrix comprises high-chromium cast iron, high-manganese steel, or alloy steel;

[0032] Preferably, the ZrO2 content in the ceramic particles composite with high-chromium cast iron is not less than 65%, and more preferably 70-80%.

[0033] Preferably, the ZrO2 content in the ceramic particles composite with alloy steel is not less than 75%, and more preferably 80-85%;

[0034] Preferably, the ZrO2 content in the ceramic particles composite with high manganese steel is not less than 80%, and more preferably 85-90%.

[0035] Fourthly, the present invention provides an application of a wear-resistant reinforcing composite material in the preparation of wear-resistant components for material crushing, grinding, scouring, pumping or excavation.

[0036] The present invention has the following beneficial effects:

[0037] The Al2O3-ZrO2 multiphase ceramic particles provided in this application have a certain surface roughness, and their shape and structure are controllable. The surface is free of cracks, which is beneficial for improving the wear resistance of composite materials in subsequent applications as reinforcing materials for steel. At the same time, it can also achieve short flow length and low cost preparation of composite materials, thereby multiplying the wear resistance of composite materials. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A schematic diagram of the initial frame blank with multi-scale interconnected channels provided for this application from a first-view perspective;

[0040] Figure 2 A schematic diagram of the initial frame blank with multi-scale interconnected channels provided in this application from a second perspective. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0042] The present invention provides an Al2O3-ZrO2 multiphase ceramic particle, which includes Al2O3 / ZrO2 ceramic particles and multiple macroscopic pits formed on the surface of Al2O3 / ZrO2 ceramic particles. The maximum projection size of the pit is 0.3 mm, and the maximum height difference between the pit and the surface is 0.3 mm.

[0043] The raw materials Al2O3 and ZrO2 have a particle size of 100nm-500nm, and the projected size of the Al2O3-ZrO2 multiphase ceramic particles is 2.7-3mm. The ZrO2 phase in the Al2O3-ZrO2 multiphase ceramic particles has a mixed structure of tetragonal and monoclinic phases, with the tetragonal phase accounting for no less than 60%.

[0044] In an optional embodiment, the Al2O3 / ZrO2 ceramic particles comprise, by weight percentage, 20-78% Al2O3, 20-78% ZrO2, 1-3% stabilizer, 0.1-0.5% binder, and 0.1-0.5% dispersant. The stabilizer includes, but is not limited to, at least one of TiO2, Y2O3, MgO, and CaO; the binder includes, but is not limited to, at least one of zinc stearate, resin, and paraffin powder; and the dispersant includes, but is not limited to, at least one of water, alcohol, and acetone.

[0045] Furthermore, the present invention provides a method for preparing Al2O3-ZrO2 multiphase ceramic particles, which includes the following steps:

[0046] Preparation of S1, Al2O3 / ZrO2 ceramic particle blanks.

[0047] Al2O3, ZrO2, stabilizer, binder, dispersant and water are mixed and granulated to obtain an Al2O3 / ZrO2 ceramic particle mixture;

[0048] The Al2O3 / ZrO2 ceramic particle mixture is formed into a quantitative dense mixture preform by centrifugal rotation, rolling, molding, extrusion, or injection molding. The mixing and granulation method includes, but is not limited to, centrifugal rotation, rolling, molding, extrusion, or injection molding of the mixture; any method that can form particles is acceptable. In this embodiment, to ensure that the Al2O3-ZrO2 multiphase ceramic particles have better performance, all raw materials used are nanoscale.

[0049] Preparation of S2, Al2O3-ZrO2 multiphase ceramic particles.

[0050] A quantitative dense mixture blank is roll-formed onto a roller to form multiple macroscopic pits.

[0051] In this application, roll forming is performed using a roller device with a first roller and a second roller in parallel contact. A storage hopper for holding a quantitative dense mixture blank is located above the space between the first and second rollers. Both the first and second rollers are machined with multiple forming countersunk holes for creating pits. The roll forming method includes: when the first and second rollers rotate towards each other, the quantitative dense mixture blank in the storage hopper enters between the first and second rollers and enters two corresponding forming countersunk holes. The first and second rollers rotate towards each other, closing and compacting the two corresponding forming countersunk holes to form ceramic particles with pits. Preferably, the shape of the forming countersunk holes is spherical, elliptical, or polygonal. The maximum projected dimension of the forming countersunk hole is 0.3 mm, and the maximum height difference between the pit and the spherical surface is 0.3 mm. This ensures good uniformity of the formed pits.

[0052] This invention employs centrifugal rotation, rolling, molding, extrusion, or injection molding. During these processes, the particles are shaped and further densified, resulting in a particle shape projection size of 2.7-3 mm. This achieves relatively uniform shape and size of the ceramic particles, ensuring relatively uniform micropores among the ceramic particles in the preform. Furthermore, the formation of pits helps improve the surface roughness of the Al2O3 / ZrO2 ceramic particles, thereby enhancing the bonding effect between the Al2O3 / ZrO2 ceramic particles and the steel matrix, making it less prone to peeling off under impact and high stress.

[0053] Furthermore, the present invention also provides a wear-resistant reinforcing composite material, which includes the following steps:

[0054] (1) Nickel alloy powder is coated on the surface of Al2O3-ZrO2 composite ceramic particles to form a wear-resistant material reinforcement.

[0055] The mass ratio of nickel alloy powder to Al2O3-ZrO2 multiphase ceramic particles is 10-20:90-80; the particle size of the nickel alloy powder is 1-5μm.

[0056] (2) The wear-resistant material reinforcement is placed in the mold and pressed to form a frame blank with multi-scale interconnected channels.

[0057] This invention uses a mold to shape the wear-resistant material reinforcement into a frame blank with multi-scale interconnected channels, which is beneficial for supporting the subsequent casting of melt and for the melt and frame blank to combine to form a composite material.

[0058] (3) The initial frame body is dried, sintered and cooled to obtain a ceramic particle frame body;

[0059] Specifically, the initial framework blank is dried at 50-80℃ for 5-10 hours, then heated to 1450-1500℃ at a rate not exceeding 80℃ / h, and sintered for 6-10 hours. After sintering, it is cooled to 1100-1190℃ at a rate of 50-60℃ / min and held for 1-3 hours, followed by air cooling to room temperature to obtain a ceramic particle framework. The tetragonal ZrO2 phase content is not less than 60% of the ZrO2 phase. The low-temperature sintering at 1450-1500℃ in this invention can ensure that the ceramic particles are fine and uniform.

[0060] (4) Place the ceramic particle framework in the mold, pour the melt of wear-resistant material, and solidify and cool to obtain the wear-resistant reinforced composite material.

[0061] The wear-resistant materials include high-chromium cast iron, high-manganese steel, or alloy steel; the mass ratio of ceramic particle frame to wear-resistant material is 30-60:70-40.

[0062] The wear-resistant reinforced composite material obtained by the above preparation method can be widely used in the preparation of wear-resistant components for material crushing, grinding, scouring, pumping or excavation.

[0063] The traditional preparation of wear-resistant reinforced composite materials requires, after forming a preliminary framework, first molding ceramic particles to form a preliminary framework, then sintering the preliminary framework to give it a certain strength, then performing surface plating treatment, followed by sintering to form a framework, and finally casting. Therefore, the preparation of traditional wear-resistant reinforced composite materials requires at least two sintering processes.

[0064] In this application, nickel-containing alloy powder is first coated onto the surface of the Al2O3-ZrO2 multiphase ceramic particles. During subsequent sintering, the nickel-containing alloy powder melts and adheres to the surface of the Al2O3-ZrO2 multiphase ceramic particles. Simultaneously, the melted nickel-containing alloy powder also acts as a binder, forming a stable framework around the Al2O3-ZrO2 multiphase ceramic particles. Later, during the casting of the melt, the molten nickel-containing alloy powder undergoes a metallurgical interface bonding with the molten wear-resistant material matrix, which helps to strengthen the bonding strength. This application achieves both the surface treatment of the nickel-containing alloy powder and the treatment of the framework through a single sintering process, realizing one-time molding and simplifying the operation.

[0065] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0066] Example 1

[0067] This embodiment provides an Al2O3-ZrO2 multiphase ceramic particle, the preparation method of which is as follows:

[0068] (1) 70% Al2O3, 27% ZrO2, 2.4% stabilizer, 0.3% binder and 0.3% dispersant are mixed and rolled into Al2O3 / ZrO2 ceramic blanks by rolling the mixture with a rolling disc. The rolling disc includes an upper rolling disc and a lower rolling disc that are meshed in a gear shape. The gap between the gear meshing of the upper rolling disc and the lower rolling disc is 1 μm, the pressure is 50 MPa, and the rotation speed is 80 rpm to form a quantitative dense mixture blank.

[0069] (2) A quantitative dense mixture blank is fed between the first roller and the second roller and enters into two corresponding forming holes. The first roller and the second roller rotate in opposite directions to close and compact the two corresponding forming holes, forming ceramic particles with pits.

[0070] The Al2O3 and ZrO2 raw materials have a particle size of 100nm-500nm. The ZrO2 phase is a mixture of tetragonal and monoclinic phases, with the tetragonal phase accounting for 65% of the mass.

[0071] Example 2

[0072] This embodiment provides an Al2O3-ZrO2 multiphase ceramic particle, the preparation method of which is as follows:

[0073] (1) Mix 60% Al2O3, 36% ZrO2, 3% stabilizer, 0.5% binder and 0.5% dispersant, and roll the mixture with a rolling mill to obtain Al2O3 / ZrO2 ceramic particle blanks. The rolling mill includes an upper rolling mill and a lower rolling mill that mesh in a gear shape. The gap between the gears of the upper rolling mill and the lower rolling mill is 0.8 μm, the pressure is 80 MPa, and the rotation speed is 50 rpm to form a quantitative dense mixture blank.

[0074] (2) A quantitative dense mixture blank is fed between the first roller and the second roller and enters into two corresponding forming holes. The first roller and the second roller rotate in opposite directions to close and compact the two corresponding forming holes, forming ceramic particles with pits. The particle size of the Al2O3-ZrO2 multiphase ceramic particles is 100nm-500nm. The ZrO2 phase is a mixture of tetragonal and monoclinic phases, with the tetragonal phase accounting for 75% of the mass.

[0075] Example 3

[0076] This embodiment provides an Al2O3-ZrO2 multiphase ceramic particle, the preparation method of which is as follows:

[0077] (1) Mix 36% Al2O3, 60% ZrO2, 3% stabilizer, 0.5% binder and 0.5% dispersant, and roll the mixture with a rolling mill to obtain Al2O3 / ZrO2 ceramic particle blanks. The rolling mill includes an upper rolling mill and a lower rolling mill that are meshed in a gear shape. The gap between the meshing gears of the upper rolling mill and the lower rolling mill is 0.5 μm, the pressure is 100 MPa, and the rotation speed is 100 rpm to form a quantitative dense mixture blank.

[0078] (2) A quantitative dense mixture blank is fed between the first roller and the second roller and enters into two corresponding forming holes. The first roller and the second roller rotate in opposite directions to close and compact the two corresponding forming holes, forming ceramic particles with pits. The particle size of the Al2O3-ZrO2 multiphase ceramic particles is 100nm-500nm. The ZrO2 phase is a mixture of tetragonal and monoclinic phases, with the tetragonal phase accounting for 85% of the mass.

[0079] Example 4

[0080] This embodiment provides an Al2O3-ZrO2 multiphase ceramic particle, the preparation method of which is as follows:

[0081] (1) Mix 30% Al2O3, 68% ZrO2, 1.8% stabilizer, 0.1% binder and 0.1% dispersant, and extrude the mixture to obtain Al2O3 / ZrO2 ceramic particle blanks to form a quantitative dense mixture blank.

[0082] (2) A quantitative dense mixture blank is fed between the first roller and the second roller and enters into two corresponding forming holes. The first roller and the second roller rotate in opposite directions to close and compact the two corresponding forming holes, forming ceramic particles with pits. The particle size of the Al2O3-ZrO2 multiphase ceramic particles is 100nm-500nm. The ZrO2 phase is a mixture of tetragonal and monoclinic phases, with the tetragonal phase accounting for 80% of the mass.

[0083] Example 5

[0084] This embodiment provides a wear-resistant reinforcing composite material, the preparation method of which includes:

[0085] (1) The surface of the Al2O3-ZrO2 composite ceramic particles obtained in Example 1 above is coated with nickel alloy powder with a particle size of 1-5 μm, and the mass ratio of nickel alloy powder to Al2O3-ZrO2 composite ceramic particles is 12:88.

[0086] (2) The wear-resistant material reinforcement is placed in a mold and pressed to form a frame blank with multi-scale interconnected channels (e.g. Figure 1 and Figure 2 (as shown)

[0087] (3) Dry the initial frame body at 65°C for 8 hours, then heat it to 1480°C at a heating rate of no more than 80°C / h, sinter for 8 hours, and after sintering, cool it down to 1150°C at a cooling rate of 55°C / min and hold for 2 hours, and then air cool it to room temperature to obtain the ceramic particle frame body.

[0088] (4) Place the ceramic particle framework in the mold, pour the melt of high chromium cast iron, and solidify and cool to obtain the wear-resistant reinforced composite material.

[0089] Example 6

[0090] This embodiment provides a wear-resistant reinforcing composite material, the preparation method of which includes:

[0091] (1) The surface of the Al2O3-ZrO2 composite ceramic particles obtained in Example 1 above is coated with nickel alloy powder with a particle size of 1-5 μm, and the mass ratio of nickel alloy powder to Al2O3-ZrO2 composite ceramic particles is 15:85.

[0092] (2) The wear-resistant material reinforcement is placed in a mold and extruded to form a frame blank with multi-scale interconnected channels;

[0093] (3) Dry the initial frame body at 50°C for 10 hours, then heat it to 1450°C at a heating rate of no more than 80°C / h, sinter for 10 hours, and after sintering, cool it down to 1190°C at a cooling rate of 50°C / min and hold for 1 hour, and then air cool it to room temperature to obtain the ceramic particle frame body.

[0094] (4) Place the ceramic particle framework in the mold, pour the melt of high chromium cast iron, and solidify and cool to obtain the wear-resistant reinforced composite material.

[0095] Example 7

[0096] This embodiment provides a wear-resistant reinforcing composite material, the preparation method of which includes:

[0097] (1) The surface of the Al2O3-ZrO2 composite ceramic particles obtained in Example 1 above is coated with nickel alloy powder with a particle size of 1-5 μm, and the mass ratio of nickel alloy powder to Al2O3-ZrO2 composite ceramic particles is 15:85.

[0098] (2) The wear-resistant material reinforcement is placed in a mold and extruded to form a frame blank with multi-scale interconnected channels;

[0099] (3) Dry the initial frame body at 80°C for 5 hours, then heat it to 1500°C at a heating rate of no more than 80°C / h, sinter for 6 hours, and after sintering, cool it down to 1100°C at a cooling rate of 60°C / min and hold for 3 hours, and then air cool it to room temperature to obtain the ceramic particle frame body.

[0100] (4) Place the ceramic particle framework in the mold, pour the melt of high chromium cast iron, and solidify and cool to obtain the wear-resistant reinforced composite material.

[0101] Comparative Example 1

[0102] In this comparative example, step (2) of Example 1 has been omitted.

[0103] Comparative Example 2

[0104] In this comparative example, step (2) in Example 1 is modified to form pits on the surface of Al2O3 / ZrO2 ceramic particle blanks by laser engraving.

[0105] Comparative Example 3

[0106] In this comparative example, step (3) in Example 5 is modified as follows:

[0107] The initial frame blank was dried at 80℃ for 8 hours, then heated to 1650℃ at a heating rate of no more than 80℃ / h and sintered for 6 hours. After sintering, it was cooled to 1100℃ at a cooling rate of 60℃ / min and held for 3 hours. Then it was air-cooled to room temperature to obtain the ceramic particle frame.

[0108] Comparative Example 4

[0109] This comparative example provides a traditional preparation process for preparing wear-resistant composite materials from Al2O3 / ZrO2 ceramic particles: ceramic particles are sintered at 1500℃ for 10 hours, nickel alloy powder is coated onto the ceramic particles, the nickel alloy powder-coated ceramic particles are coated with a binder and then sintered into a framework body at a sintering temperature of 1480℃, the framework body is placed in a mold to cast high-chromium cast iron melt, and solidification and cooling are performed to obtain the composite material.

[0110] Experimental Example

[0111] The properties of the ceramic particles obtained in Examples 1-4 and Comparative Examples 1-2 were tested according to standard methods, and the test results are as follows.

[0112]

[0113] The wear resistance properties of the wear-resistant reinforced composite materials obtained in Examples 5-7 and Comparative Examples 3-4 were tested according to standard methods, and the test results are as follows.

[0114]

[0115] As can be seen from the table above, the Al2O3-ZrO2 multiphase ceramic particles provided in Examples 1-4 of this application have good microstructure and shape, good pitting, no crack formation, and significantly better strength and fracture toughness than Comparative Examples 1 and 2. Data from Comparative Example 2 shows that pit formation requires continuous closing and compaction during the preparation process. During pit formation, the quantitatively dense mixture blank is further compressed and densified, and the surface roughness is improved, thereby enhancing the bonding effect between the Al2O3 / ZrO2 ceramic particles and the steel matrix. Laser engraving does not have this further compression and densification effect, and the surface roughness differs from Example 1, resulting in a less satisfactory effect. In contrast, the wear resistance of Examples 5-7 of this application is significantly better than that of Comparative Example 3, and the cost is significantly reduced.

[0116] This study found that, in order to significantly improve the wear resistance of steel-based composite materials, Al2O3 and ZrO2, as reinforcing materials, need to meet the following properties: controllable ceramic particle structure and shape, certain surface roughness, no surface cracks, and high strength and toughness.

[0117] (1) Regarding the controllability of the microstructure, room-temperature Al2O3 and ZrO2 ceramic particles obtain a tetragonal phase microstructure, which transforms into a monoclinic phase during service. The present invention adopts the following measures: 1) The raw material for making ceramic particles is nanoscale; 2) Through the addition of stabilizers, the constraint effect of Al2O3 on ZrO2, the heat treatment temperature and controlled cooling, and the constraint effect of the steel matrix on ZrO2, the tetragonal phase microstructure is obtained at room temperature.

[0118] (2) Regarding shape controllability, current methods for preparing ceramic particle-reinforced steel-based composite materials involve fabricating ceramic particles into preforms with interconnected multi-scale pores. Gravity casting infiltration is used, where molten steel infiltrates the micro-pores between the ceramic particles. After cooling and solidification, the steel-based composite material is obtained. During the casting infiltration process, the molten steel infiltrates sequentially according to the pore size, from largest to smallest. When small pores between ceramic particles in the preform are surrounded by large pores, the small pores cannot penetrate, resulting in pores. Therefore, the uniformity of pore size is crucial; large differences in pore size lead to defects such as pores or looseness in the composite material. This invention employs rolling, molding, extrusion, or injection molding, combined with a centrifugal rotating device. The particles are shaped and further densified during interaction with the centrifugal device wall, resulting in a particle shape projection size of 2.7-3 mm. This achieves relatively consistent ceramic particle shape and size, ensuring relatively uniform micro-pores between ceramic particles in the preform.

[0119] (3) In terms of roughness, the roughness of the ceramic particle surface can make the steel matrix interlock with the ceramic particles, and the ceramic particles are not easy to peel off under impact and high stress. The measures taken in this invention are: using a centrifugal rotating device to make the particles dense and shaped during the interaction with the centrifugal device wall, the particle surface has a macroscopic concave pit shape, the maximum size of the pit projection is 0.3 mm, and the maximum height difference between the pit and the surface is 0.3 mm.

[0120] (4) Regarding the absence of surface cracks, the absence of surface cracks can give ceramic particles high toughness and lack crack sources during service.

[0121] (5) In terms of strength and toughness, Al2O3 and ZrO2 particles have good strength and toughness, so the composite material resists impact and wear resistance better under strong impact and high stress. This invention has several measures: 1) The ceramic particles are made of nano-sized raw materials; 2) The ceramic powder slurry is prepared by rolling and mixing to ensure the uniformity of the nano-powder; 3) Low-temperature sintering at 1450-1500°C is used; the above measures ensure that the ceramic particles are fine and uniform. 4) Through the addition of stabilizers, the constraint effect of Al2O3 on ZrO2, the heat treatment temperature and controlled cooling, and the constraint effect of the steel matrix on ZrO2, the ceramic particles ZrO2 obtain a tetragonal phase at room temperature. During service, the tetragonal phase improves the toughness of the composite material through toughening methods such as phase transformation toughening, microcrack toughening, and stress release toughening, while also improving wear resistance. In summary, the strength and toughness of the ceramic particles are improved, and the strength, toughness, and wear resistance of the composite material are improved.

[0122] (6) Regarding low-cost control, this invention integrates the sintering of ceramic particles and the sintering of the activated framework body into a single process. Specifically, the surface of the ceramic particle blank with pits has a slight moisture content, allowing nickel alloy powder to adhere. The blank ceramic particles coated with nickel alloy powder are then placed in a mold to obtain a multi-scale interconnected pore framework blank. The framework blank is then dried and sintered, with the cooling rate controlled, to obtain the ceramic particle framework body. Therefore, the process flow is shortened, and the production cost is reduced.

[0123] In summary, the Al2O3-ZrO2 multiphase ceramic particles provided in this application have a certain surface roughness, and their shape and structure are controllable. The surface is free of cracks, which is beneficial for improving the wear resistance of composite materials in subsequent applications as reinforcing materials for steel. At the same time, it can also achieve low-cost preparation of composite materials and achieve a significant increase in the wear resistance of composite materials.

[0124] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing Al2O3-ZrO2 multiphase ceramic particles, characterized in that, The Al2O3-ZrO2 multiphase ceramic particles include Al2O3 / ZrO2 ceramic particles and multiple macroscopic pits formed on the surface of the Al2O3 / ZrO2 ceramic particles. The maximum projected size of the pits is 0.3 mm, and the maximum height difference between the pits and the surface is 0.3 mm. The preparation method includes mixing and granulating the components of the Al2O3 / ZrO2 ceramic particles to obtain an Al2O3 / ZrO2 ceramic particle mixture; The Al2O3 / ZrO2 ceramic particle mixture is centrifuged, rolled, molded, extruded or injected to form a quantitative dense mixture preform; the quantitative dense mixture preform is then rolled by roller pressing to form multiple macroscopic pits, thus obtaining Al2O3-ZrO2 multiphase ceramic particles. The roll forming process employs a roller device consisting of a first roller and a second roller in parallel contact. A storage hopper for placing a quantitative dense mixture blank is provided above the space between the first roller and the second roller. Both the first roller and the second roller are machined with multiple forming countersunk holes for forming pits. The roll forming method includes: when the first roller and the second roller are running in opposite directions, the quantitative dense mixture blank in the storage hopper enters between the first roller and the second roller and enters two corresponding forming countersunk holes. The first roller and the second roller rotate in opposite directions, closing and compacting the two corresponding forming countersunk holes to form ceramic particles with pits.

2. The method for preparing Al2O3-ZrO2 multiphase ceramic particles according to claim 1, characterized in that, The shape of the countersunk hole is spherical, elliptical, or polygonal.

3. The method for preparing Al2O3-ZrO2 multiphase ceramic particles according to claim 1, characterized in that, The ZrO2 phase in the Al2O3-ZrO2 multiphase ceramic particles is a mixture of tetragonal and monoclinic phases, with the tetragonal phase accounting for no less than 60%.

4. The method for preparing Al2O3-ZrO2 multiphase ceramic particles according to claim 1, characterized in that, The components of the Al2O3 / ZrO2 ceramic particles, by weight percentage, include 20-78% Al2O3, 20-78% ZrO2, 1-3% stabilizer, 0.1-0.5% binder, and 0.1-0.5% dispersant.

5. The method for preparing Al2O3-ZrO2 multiphase ceramic particles according to claim 4, characterized in that, The particle size of both Al2O3 and ZrO2 is 100nm-500nm.

6. The method for preparing Al2O3-ZrO2 multiphase ceramic particles according to claim 4, characterized in that, The stabilizer is at least one of TiO2, Y2O3, MgO and CaO.

7. The method for preparing Al2O3-ZrO2 multiphase ceramic particles according to claim 4, characterized in that, The binder is at least one of zinc stearate, resin and paraffin powder.

8. The method for preparing Al2O3-ZrO2 multiphase ceramic particles according to claim 4, characterized in that, The dispersant is at least one of water, alcohol, and acetone.

9. A method for preparing a wear-resistant reinforced composite material, characterized in that, It includes: Nickel-containing alloy powder is coated onto the surface of Al2O3-ZrO2 multiphase ceramic particles prepared by the method described in any one of claims 1-8 to form a wear-resistant material reinforcement. The wear-resistant material reinforcement is placed in a mold and pressed to form a frame blank with multi-scale interconnected channels; The initial frame body is dried, sintered and cooled to obtain a ceramic particle frame body. The sintering includes heating to 1450-1550°C at a heating rate of no more than 80°C / h and sintering for 6-10h. The ceramic particle framework is placed in a mold, and the melt of the wear-resistant material matrix is ​​poured in. After solidification and cooling, a wear-resistant reinforced composite material is obtained.

10. The method for preparing the wear-resistant reinforced composite material according to claim 9, characterized in that, The mass ratio of the nickel-containing alloy powder to the Al2O3-ZrO2 multiphase ceramic particles is 10-20:90-80.

11. The method for preparing the wear-resistant reinforced composite material according to claim 9, characterized in that, The particle size of the nickel-containing alloy powder is 1-5 μm.

12. The method for preparing the wear-resistant reinforced composite material according to claim 9, characterized in that, The drying process includes drying at a temperature of 50-80°C for 5-10 hours.

13. The method for preparing the wear-resistant reinforced composite material according to claim 9, characterized in that, The cooling process in the step of obtaining ceramic particle framework after drying, sintering and cooling the initial framework blank includes: cooling to 1100-1190°C at a cooling rate of 50-60°C / min and holding for 1-3 hours, followed by air cooling to room temperature, wherein the content of ZrO2 tetragonal phase accounts for not less than 60% of the ZrO2 phase.

14. The method for preparing the wear-resistant reinforced composite material according to claim 9, characterized in that, The mass ratio of the ceramic particle framework to the wear-resistant material matrix is ​​30-60:70-40.

15. The method for preparing the wear-resistant reinforced composite material according to claim 9, characterized in that, The wear-resistant material matrix includes high-chromium cast iron, high-manganese steel, or alloy steel.

16. The method for preparing the wear-resistant reinforced composite material according to claim 15, characterized in that, The ZrO2 content in the ceramic particles composite with high-chromium cast iron is not less than 65%.

17. The method for preparing the wear-resistant reinforced composite material according to claim 16, characterized in that, The ZrO2 content in the ceramic particles composite with high-chromium cast iron is 70-80%.

18. The method for preparing the wear-resistant reinforced composite material according to claim 15, characterized in that, The ZrO2 content in the ceramic particles combined with alloy steel is not less than 75%.

19. The method for preparing the wear-resistant reinforced composite material according to claim 18, characterized in that, The ZrO2 content in the ceramic particles combined with alloy steel is 80-85%.

20. The method for preparing the wear-resistant reinforced composite material according to claim 15, characterized in that, The ZrO2 content in the ceramic particles composite with high manganese steel is not less than 80%.

21. The method for preparing the wear-resistant reinforced composite material according to claim 20, characterized in that, The ZrO2 content in the ceramic particles composited with high manganese steel is 85-90%.

22. The application of the wear-resistant reinforced composite material prepared by the method of any one of claims 14-21 in the preparation of wear-resistant components for material crushing, grinding, scouring, pumping or excavation.

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