Wear-resistant aluminum oxide ceramic and preparation method thereof

Abstract

The invention discloses a wear-resistant aluminum oxide ceramic and a preparation method thereof, and particularly relates to the field of aluminum oxide ceramics, a main body ceramic phase comprises alpha-type aluminum oxide, beta-type aluminum oxide, mullite and spinel; the self-healing phase comprises a nickel-titanium alloy wire, a titanium nitride coating and silicon carbide particles; the sensing phase comprises a polydimethylsiloxane capsule, a cholesteric liquid crystal mixture and cerium-doped yttrium aluminum garnet fluorescent particles; the energy-absorbing temperature-regulating phase comprises a metal organic framework material ZIF-8, a metal organic framework material MIL-101 (Fe) and carbon dioxide gas; the buffer lubricating phase comprises bentonite sheets and hexagonal boron nitride nanosheets. By synergistically introducing a self-healing phase, a sensing phase, an energy-absorbing temperature-regulating phase and a buffering lubricating phase into the aluminum oxide ceramic, multifunctional integration of crack blocking, self-healing, real-time monitoring, impact buffering and friction reduction is realized, so that the technical bottleneck problem that microcracks in an existing ceramic material are invisible and cannot be monitored is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of alumina ceramics. More specifically, the present invention relates to a wear-resistant alumina ceramic and a preparation method thereof. Background Art

[0002] In high-wear and impact applications, although alumina ceramics can improve the crack-blocking ability by doping NiTi microfilaments, the prior art has always ignored a fatal weakness: the invisibility of cracks. In actual use, microcracks inside the ceramic often occur without warning at an extremely early stage and continue to expand. Maintenance personnel cannot perceive or locate these hidden damages without damaging the workpiece, resulting in the premature failure of components that could have been saved. In addition, even if NiTi achieves local structural recovery, it cannot provide real-time feedback on the health state of the material. This dilemma of "structurally intact but losing monitoring" has become a technical bottleneck restricting the reliable application of composite ceramics. Summary of the Invention

[0003] In order to overcome the above defects of the prior art, embodiments of the present invention provide a wear-resistant alumina ceramic and a preparation method thereof. By synergistically introducing a self-healing phase, a sensing phase, an energy-absorbing and temperature-regulating phase, and a buffer lubricating phase into the alumina ceramic, multi-functional integration of crack blocking, self-healing, real-time monitoring, impact buffering, and friction reduction is achieved, thereby solving the technical bottleneck problem of invisible and uncontrollable microcracks in existing ceramic materials.

[0004] To achieve the above object, the present invention provides the following technical solution: A wear-resistant alumina ceramic and a preparation method thereof, including the following mass fraction ratios: 70 - 80 parts of the main ceramic phase, including α-aluminum oxide, β-aluminum oxide, mullite, and spinel; 8 - 12 parts of the self-healing phase, including nickel-titanium alloy wires, titanium nitride coatings, and silicon carbide particles; 1 - 3 parts of the sensing phase, including polydimethylsiloxane capsules, cholesteric liquid crystal mixtures, and cerium-doped yttrium aluminum garnet fluorescent particles; 3 - 6 parts of the energy-absorbing and temperature-regulating phase, including metal-organic framework material ZIF-8, metal-organic framework material MIL-101(Fe), and carbon dioxide gas; 1 - 3 parts of the buffer lubricating phase, including bentonite flakes and hexagonal boron nitride nanosheets.

[0005] In a preferred embodiment, it includes the following mass fraction ratios: In the main ceramic phase: 56 - 72 parts of α-aluminum oxide (particle size 0.5 - 2 μm) are selected, 3 - 6 parts of β-aluminum oxide (particle size 0.3 - 1 μm) are selected, mullite ( , those with a particle size < 2 μm) are selected in an amount of 2 - 4 parts, and spinel ( , with a particle size < 1 μm) is selected in an amount of 1 - 3 parts; among them, α-aluminum oxide is alumina with a thermodynamically stable corundum structure, and β-aluminum oxide refers to an alumina phase with a layered crystal structure, containing sodium ion channels, and having ionic conductivity, belonging to a superionic conductor-type intermediate phase alumina; In the self-healing phase: nickel-titanium alloy wire (Ni55Ti45 atomic ratio, wire diameter 10 - 30 μm) is selected in an amount of 7 - 10 parts, titanium nitride coating (coating the nickel-titanium alloy wire, coating thickness 100 - 300 nm) is selected in an amount of 0.5 - 1 part, and silicon carbide particles (particle size 100 - 300 nm) are selected in an amount of 0.5 - 1 part; In the sensing phase: polydimethylsiloxane capsules (viscosity 500 - 1000 cP, mass encapsulation rate ≥ 90%) are selected in an amount of 0.6 - 2 parts, cholesteric liquid crystal mixture (composed of 7:3 cholesteryl octanoate and cholesteryl heptanoate, color change temperature 25 - 45 °C) is selected in an amount of 0.2 - 0.7 parts, and cerium-doped yttrium aluminum garnet fluorescent particles ( , with a particle size of 50 - 200 nm) are selected in an amount of 0.2 - 0.5 parts; among them, the mass encapsulation rate in the polydimethylsiloxane capsules refers to the mass fraction of the cholesteric liquid crystal mixture completely encapsulated by polydimethylsiloxane as the outer shell, with polydimethylsiloxane capsules as the outer shell and the cholesteric liquid crystal mixture as the core; among them, cholesteryl octanoate and cholesteryl heptanoate are isomers, and their chemical formulas are both ; In the energy-absorbing and temperature-regulating phase: metal-organic framework ZIF-8 ( , with a particle size of 100 - 300 nm) is selected in an amount of 1 - 2 parts, metal-organic framework MIL-101(Fe) ( , with a particle size of 100 - 300 nm) is selected in an amount of 1 - 2 parts, and carbon dioxide gas (filled into the pore structures of metal-organic framework ZIF-8 and metal-organic framework MIL-101(Fe)) is selected in an amount of 0.3 - 0.8 parts; In the buffer lubricating phase: bentonite flakes (particle size 1 - 5 μm) are selected in an amount of 0.5 - 2 parts, hexagonal boron nitride nanosheets (h-BN, thickness 10 - 100 nm) are selected in an amount of 0.5 - 1 part, among which bentonite flakes are an aquifer-like layered silicate mineral, the main component of which is montmorillonite, and the chemical formula is: , where Na and Ca are variable exchange cations, and Al and Mg are octahedral cations between layers, indicates containing crystal water; in addition, the parts ratio in each phase refers to the mass parts ratio of each component in the phase relative to the total mass of the phase.

[0006] A preparation method of a wear-resistant alumina ceramic, comprising: Step 1: Preparation of the main ceramic phase raw material mixture: Weigh α-aluminum oxide, β-aluminum oxide, mullite, and spinel according to a preset mass ratio, add them to a ball milling device, add a polyvinyl alcohol solution with a mass concentration of 3-5% as a dispersant, and perform wet ball milling for 12-24 hours to obtain a main ceramic phase mixture; Step 2: Preparation of self-healing phase material: Cut the nickel-titanium alloy wire to a length of 2-5 mm, deposit a titanium nitride coating on the surface of the nickel-titanium alloy wire by physical vapor deposition, and uniformly blend the nickel-titanium alloy wire coated with the titanium nitride coating and silicon carbide particles in an ultrasonic dispersion device to obtain a self-healing phase material; Step 3: Preparation of sensing phase composite material: Dissolve the cholesteric liquid crystal mixture in an organic solvent, and use the microdroplet emulsification method to coat the cholesteric liquid crystal mixture in a polydimethylsiloxane capsule with polydimethylsiloxane as the shell material to form a polydimethylsiloxane capsule containing a cholesteric liquid crystal mixture core. Mix the obtained polydimethylsiloxane capsule and cerium-doped yttrium aluminum garnet fluorescent particles under stirring conditions of 100-200 rpm to obtain a sensing phase composite material; wherein the organic solvent includes ethanol or ethyl acetate; Step 4: Preparation of energy-absorbing and temperature-regulating phase composite material: Weigh metal-organic framework ZIF-8 and metal-organic framework MIL-101(Fe) according to a preset mass ratio, perform dry mixing for 2-4 hours, and then place the dry-mixed mixture in a vacuum adsorption device and fill it with carbon dioxide gas for 12-24 hours to obtain an energy-absorbing and temperature-regulating phase composite material; Step 5: Preparation of buffer lubricating phase composite material: Prepare bentonite sheets by wet stripping method and hexagonal boron nitride nanosheets by mechanical stripping method. Weigh the bentonite sheets and hexagonal boron nitride nanosheets according to a preset mass ratio and perform dry mixing for 30-60 minutes to obtain a buffer lubricating phase composite material; wherein the wet stripping method includes, but is not limited to, dispersing bentonite in deionized water and using ultrasonic treatment (including, but is not limited to, a frequency of 20-40 kHz and a time of 30-60 minutes) to promote the separation of the layered structure to form single-layer or few-layer bentonite sheets; wherein the mechanical stripping method includes, but is not limited to, placing hexagonal boron nitride bulk material in a ball mill or a shear mixer and applying high shear force or mechanical impact force (including, but is not limited to, planetary ball milling, a speed of 200-400 rpm, and a time of 2-6 hours) to achieve physical interlayer peeling to obtain hexagonal boron nitride nanosheets; Step 6: Preparation of composite ceramic premix: Put the main body ceramic phase mixture, self-healing phase material, sensing phase composite material, energy-absorbing and temperature-regulating phase composite material, and buffer lubricating phase composite material into a mixing device according to a preset mass ratio, add a polyvinyl alcohol solution with a mass concentration of 3%-5% as a temporary binder, and mix for 2-4 hours under the condition of a stirring speed of 80-150 rpm to obtain a composite ceramic premix; Step 7: Molding of the composite ceramic green body: Place the composite ceramic premix into an isostatic pressing mold, apply a pressure of 150-250 MPa, and maintain the pressure for 5-10 minutes to form a composite ceramic green body; Step 8: Sintering of the composite ceramic: Place the composite ceramic green body in a sintering furnace under an argon protection atmosphere, heat it to 1450-1600 °C at a heating rate of 2-5 °C / minute, keep it warm for 2-4 hours and then cool it to obtain the sintered composite ceramic material; In addition, in practical applications, it also includes: Step 9 Post-treatment of the composite ceramic material: Perform mechanical polishing on the sintered composite ceramic material to remove surface residues, use a metallographic microscope and a scanning electron microscope to detect its density and component uniformity, and conduct stress tests to verify the stress response performance of the sensing phase composite material.

[0007] Technical effects and advantages of the present invention: 1. Realize visual monitoring of cracks: Through the combination of a cholesteric liquid crystal mixture and cerium-doped yttrium aluminum garnet fluorescent particles, the color and light intensity changes during the occurrence of microcracks are realized, providing real-time feedback on the health status of the material.

[0008] 2. Improve the self-healing ability of microcracks: Nickel-titanium alloy wires combined with titanium nitride coatings and silicon carbide particles form a self-healing structure of stress-induced closure and stress diffusion at the crack tip.

[0009] 3. Enhance impact energy absorption and thermal buffering: The porous materials of ZIF-8 and MIL-101(Fe) are filled with carbon dioxide to disperse impact loads and buffer thermal stresses, reducing the risk of brittle fracture.

[0010] 4. Reduce friction and wear: The hydrated layer of bentonite and h-BN nanosheets synergistically reduce the friction coefficient and wear rate, extending the material life.

[0011] 5. Based on α-aluminum trioxide, β-aluminum trioxide, mullite, and spinel, provide multifunctional properties such as high strength and toughness. Description of the drawings

[0012] Figure 1 It is a flow chart of the preparation method of the present invention. Detailed implementation manners

[0013] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0014] Referring to the attached Figure 1 drawings of the specification, a wear-resistant alumina ceramic and its preparation method of the present invention include the following examples and comparative examples: Example 1: Step 1: Add 56 parts of α-aluminum trioxide, 4 parts of β-aluminum trioxide, 3 parts of mullite, and 2 parts of spinel into a ball milling device, add a 3% mass concentration polyvinyl alcohol solution as a dispersant, and perform wet ball milling for 16 hours to obtain a main ceramic phase mixture; Step 2: Cut nickel-titanium alloy wires (Ni55Ti45 atomic ratio, wire diameter 20 μm) to a length of 3 mm, deposit a titanium nitride coating (thickness 200 nm) on its surface by physical vapor deposition method, and blend it with silicon carbide particles (particle size 200 nm) in an ultrasonic dispersion device to obtain a self-healing phase material, with a ratio of 8 parts of nickel-titanium alloy wires, 1 part of titanium nitride coating, and 1 part of silicon carbide particles; Step 3: Dissolve a cholesteric liquid crystal mixture (composed of 7:3 cholesteryl octanoate and cholesteryl heptanoate to achieve a target color change temperature in the range of 25-45 °C) in ethyl acetate, and use the microdroplet emulsification method to coat it in a polydimethylsiloxane capsule with a polydimethylsiloxane with a viscosity of 500-1000 cP as the shell material to form a polydimethylsiloxane capsule containing a cholesteric liquid crystal mixture core (mass coating rate ≥ 90%), and then mix it with cerium-doped yttrium aluminum garnet fluorescent particles (particle size 100 nm) under stirring conditions of 100-200 rpm to obtain a sensing phase composite material, with a ratio of 1.5 parts of polydimethylsiloxane capsule, 0.5 part of cholesteric liquid crystal mixture, and 0.3 part of cerium-doped yttrium aluminum garnet fluorescent particles; Step 4: Dry-mix 1.5 parts of metal-organic framework ZIF-8 (particle size 200 nm) and 1.5 parts of metal-organic framework MIL-101(Fe) (particle size 200 nm) for 3 hours, place them in a vacuum adsorption device, and fill 0.5 part of carbon dioxide gas for 18 hours to obtain an energy-absorbing and temperature-regulating phase composite material; Step 5: Obtain 1.5 parts of bentonite flakes (particle size 3 μm) by wet stripping method and 1 part of hexagonal boron nitride nanosheets (thickness 50 nm) by mechanical stripping method, and perform dry mixing for 30 minutes to obtain a buffer lubricating phase composite material; Step 6: Put the five types of materials, namely the main body ceramic phase mixture, self-healing phase material, sensing phase composite material, energy-absorbing and temperature-regulating phase composite material, and buffer lubricating phase composite material, into a mixing equipment in a ratio of 70:10:2:5:2. Add a polyvinyl alcohol solution with a mass concentration of 4% as a temporary binder, and mix for 3 hours under the stirring condition of 80 - 150 rpm to obtain a composite ceramic premix; Step 7: Place the composite ceramic premix into an isostatic pressing mold, apply a pressure of 200 MPa, and maintain it for 8 minutes to form a composite ceramic green body; Step 8: Place the composite ceramic green body in an argon-protected atmosphere sintering furnace, heat it up to 1500 °C at a heating rate of 3 °C per minute, keep it warm for 3 hours, and then cool it to obtain the sintered composite ceramic material.

[0015] Example 2: Carry out according to the method of Example 1, the difference is that: In Step 1: 60 parts of α-aluminum oxide, 5 parts of β-aluminum oxide, 3 parts of mullite, 2 parts of spinel; In Step 2: 9 parts of nickel-titanium alloy wire, 0.7 part of titanium nitride coating, 0.7 part of silicon carbide particles; In Step 3: 1.2 parts of polydimethylsiloxane capsules, 0.4 part of cholesteric liquid crystal mixture, 0.3 part of cerium-doped yttrium aluminum garnet fluorescent particles; In Step 4: 1.2 parts of ZIF-8, 1.2 parts of MIL-101(Fe), 0.3 part of carbon dioxide gas; In Step 5: 1 part of bentonite flakes, 0.7 part of hexagonal boron nitride nanosheets; In Step 6: Adjust the mass ratio of the five types of materials to 70:10:2:5:2; The rest is the same as Example 1.

[0016] Example 3: Carry out according to the method of Example 1, the difference is that: In Step 1: 68 parts of α-aluminum oxide, 3.5 parts of β-aluminum oxide, 2.5 parts of mullite, 1.5 parts of spinel; In Step 2: 7.5 parts of nickel-titanium alloy wire, 0.6 part of titanium nitride coating, 0.6 part of silicon carbide particles; In Step 3: 2 parts of polydimethylsiloxane capsules, 0.7 part of cholesteric liquid crystal mixture, 0.5 part of cerium-doped yttrium aluminum garnet fluorescent particles; In Step 4: 2 parts of ZIF-8, 2 parts of MIL-101(Fe), 0.8 part of carbon dioxide gas; In Step 5: 2 parts of bentonite flakes, 1 part of hexagonal boron nitride nanosheets; In Step 6: Adjust the mass ratio of the five types of materials to 70:10:2:5:2; The rest is the same as in Example 1.

[0017] It should be noted that in Example 1, the components of each phase are configured in a medium proportion to balance the overall wear resistance, self-healing property, sensing response, and buffering and energy absorption performance, serving as a benchmark for comprehensive performance; in Example 2, the proportions of the main ceramic phase and the self-healing phase are appropriately increased to strengthen the mechanical strength and structural integrity of the material, and the proportions of the sensing and buffering materials are slightly reduced to improve the matrix density; in Example 3, the proportions of the sensing phase and the energy absorption and temperature regulation phase are further increased to enhance the intelligent response ability of the material to temperature and stress changes, and at the same time, the main ceramic phase is appropriately reduced to achieve a comprehensive multi-functional balance.

[0018] Comparative Example 1 (removing the self-healing phase): It is carried out according to the method of Example 1, with the differences being: In step 2, the nickel-titanium alloy wire, titanium nitride coating, and silicon carbide particles are not added, and the preparation step of the self-healing phase material is omitted; In step 6, the mass ratio of the four types of materials is adjusted to 78:0:3:6:3; The rest is the same as in Example 1.

[0019] Comparative Example 2 (removing the sensing phase): It is carried out according to the method of Example 1, with the differences being: In step 3, the cholesteric liquid crystal mixture, polydimethylsiloxane capsules, and cerium-doped yttrium aluminum garnet fluorescent particles are not added, and the preparation step of the sensing phase composite material is omitted; In step 6, the mass ratio of the four types of materials is adjusted to 75:12:0:7:6; The rest is the same as in Example 1.

[0020] Comparative Example 3 (removing the energy absorption and temperature regulation phase): It is carried out according to the method of Example 1, with the differences being: In step 4, the metal-organic framework ZIF-8, metal-organic framework MIL-101(Fe), and carbon dioxide gas are not added, and the preparation step of the energy absorption and temperature regulation phase composite material is omitted; In step 6, the mass ratio of the four types of materials is adjusted to 75:12:3:0:6; The rest is the same as in Example 1.

[0021] Comparative Example 4 (removing the buffering and lubricating phase): It is carried out according to the method of Example 1, with the differences being: In step 5, the bentonite flakes and hexagonal boron nitride nanosheets are not added, and the preparation step of the buffering and lubricating phase composite material is omitted; In step 6, the mass ratio of the four types of materials is adjusted to 75:12:3:7:0; The rest is the same as in Example 1.

[0022] It should be noted that in Comparative Example 1, the self-healing phase is removed to verify whether the material still has the ability to repair its structure after stress damage without the nickel-titanium alloy wire, titanium nitride coating, and silicon carbide particles; in Comparative Example 2, the sensing phase is removed to verify whether the material loses the environmental temperature or stress sensing and self-response characteristics after the absence of polydimethylsiloxane capsules, cholesteric liquid crystal mixture, and cerium-doped yttrium aluminum garnet fluorescent particles; in Comparative Example 3, the energy-absorbing and temperature-regulating phase is removed to verify the degree of reduction in the material's external shock absorption and thermal buffering functions without adding metal-organic frameworks and carbon dioxide gas; in Comparative Example 4, the buffer lubricating phase is removed to verify the change in the material's anti-friction buffering ability and interfacial lubrication performance under the condition of no bentonite flakes and hexagonal boron nitride nanosheets.

[0023] Comparative Example 5 (removing the nickel-titanium alloy wire from the self-healing phase): It is carried out according to the method of Example 1, with the difference that: In step 2, no nickel-titanium alloy wire is added, and only 1 part of titanium nitride coating and 1 part of silicon carbide particles are blended to obtain the self-healing phase material; In step 6, the mass ratio of the five types of materials remains unchanged, which is 70:10:2:5:2; The rest is the same as in Example 1.

[0024] Comparative Example 6 (removing the polydimethylsiloxane capsule from the sensing phase): It is carried out according to the method of Example 1, with the difference that: In step 3, no polydimethylsiloxane capsule is added, and only 0.5 part of cholesteric liquid crystal mixture and 0.3 part of cerium-doped yttrium aluminum garnet fluorescent particles are mixed under the stirring condition of 100 - 200 rpm to obtain the sensing phase composite material; In step 6, the mass ratio of the five types of materials remains unchanged, which is 70:10:2:5:2; The rest is the same as in Example 1.

[0025] Comparative Example 7 (removing the metal-organic framework ZIF-8 from the energy-absorbing and temperature-regulating phase): It is carried out according to the method of Example 1, with the difference that: In step 4, no metal-organic framework ZIF-8 is added, and only 1.5 parts of metal-organic framework MIL-101(Fe) and 0.5 part of carbon dioxide gas are used for treatment to obtain the energy-absorbing and temperature-regulating phase composite material; In step 6, the mass ratio of the five types of materials remains unchanged, which is 70:10:2:5:2; The rest is the same as in Example 1.

[0026] Comparative Example 8 (removing the bentonite flakes from the buffer lubricating phase): It is carried out according to the method of Example 1, with the difference that: In step 5, bentonite flakes are not added, and only 1 part of hexagonal boron nitride nanosheets is used, and dry mixing is carried out directly for 30 minutes to obtain a buffer lubricating phase composite material; In step 6, the mass ratio of the five types of materials remains unchanged, which is 70:10:2:5:2; The rest is the same as Example 1.

[0027] Comparative Example 9 (changing key process parameters): It is carried out according to the method of Example 1, with the difference that: In step 1, the wet ball milling time is shortened to 8 hours; In step 2, the thickness of the titanium nitride coating is reduced to 100 nm; In step 3, the stirring speed of the sensing phase mixing step is increased to 300 rpm; The rest is the same as Example 1.

[0028] Comparative Example 10 (the proportion of the main ceramic phase deviates from the range): It is carried out according to the method of Example 1, with the difference that: In step 6, the mass ratio of the five types of materials is adjusted to 85:6:1:5:3, exceeding the preset range; The rest is the same as Example 1.

[0029] It should be noted that Comparative Example 5 is used to verify whether the material loses the stress-induced self-healing recovery ability after removing the nickel-titanium alloy wire from the self-healing phase; Comparative Example 6 is used to verify whether the loss of the protective coating of the liquid crystal core due to the removal of the polydimethylsiloxane capsule from the sensing phase leads to a decrease or failure of the sensing function; Comparative Example 7 is used to verify whether the composite action of only MIL-101(Fe) and carbon dioxide is sufficient to maintain the impact energy absorption effect after removing ZIF-8 from the energy absorption and temperature regulation phase; Comparative Example 8 is used to verify whether the lubricating and buffering ability of the hexagonal boron nitride nanosheets alone drops significantly after removing the bentonite flakes from the buffer lubricating phase; Comparative Example 9 verifies the sensitivity of the process parameters to the final material performance by changing key parameters such as the ball milling time, the thickness of the PVD titanium nitride layer, and the stirring speed of the sensing phase; Comparative Example 10 verifies the degree of damage to the overall multi-functional synergistic performance of the material after increasing the main ceramic phase to 85 parts and exceeding the scope of the claims.

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] Regarding the overall description: The research on existing high-performance ceramic materials generally falls into the "single-performance limit" dilemma, that is, high-hardness materials generally lack toughness and self-healing ability, self-healing materials are difficult to achieve relative state perception, and functional integrated materials often lead to deterioration of overall performance due to mutual interference of components. Especially in extreme application scenarios such as high wear, high impact, and multi-temperature cycling, traditional alumina ceramics cannot achieve early perception of microcracks; Based on the analysis of the failure mechanism of traditional alumina ceramics, the present invention proposes an overall solution strategy of "five-phase coordination". The design logic starts from three levels of "multifunctional integration, complementary enhancement, and performance coordination", and systematically establishes a multiphase composite material system with structural integrity, state visualization, stress buffering, and friction reduction functions, forming the technical basis and theoretical basis of this solution; First, the main ceramic phase selects α-aluminum oxide (providing thermodynamic stability and high hardness) and β-aluminum oxide (providing layered ion conduction channels and certain deformation buffering) for mutual proportioning. Through the composite mullite and spinel to form a synergistic strengthening mechanism, on the basis of ensuring the strength and density of the material matrix, a bearing platform is provided for the subsequent functional phases; Secondly, the self-healing phase realizes triple strengthening paths by introducing Ni55Ti45 nickel-titanium alloy wires (with excellent shape memory self-healing performance), titanium nitride coatings (improving interfacial bonding force and preventing interfacial delamination), and silicon carbide particles (inhibiting crack tip propagation): that is, 1) crack initiation, stress-induced NiTi deformation recovery and closure; 2) the titanium nitride layer inhibits the thermal expansion mismatch between the alloy wire and the ceramic matrix; 3) silicon carbide provides local crack tip passivation, and the three form a closed-loop self-healing logic; The design of the sensing phase stems from the problem that traditional ceramic materials cannot achieve real-time state feedback. Polydimethylsiloxane capsules are used to coat a 7:3 ratio of cholesteryl octanoate / heptanoate mixed cholesteric liquid crystal. Through the temperature-sensitive optical color-changing characteristics of cholesteric liquid crystal (adjustable color-changing window within the range of 25-45 °C), early visual alarm of micro-temperature rise / micro-stress state is realized. At the same time, it is combined with cerium-doped yttrium aluminum garnet fluorescent particles to achieve stress-induced photoluminescence changes, forming a dual real-time monitoring system for the health state of the material; The design basis of the energy-absorbing and temperature-regulating phase is to solve the brittle fracture problem of ceramic materials under transient impact loading. MOF materials (ZIF-8 and MIL-101(Fe)) provide a high specific surface area and a porous framework structure, which can achieve dual energy dissipation of energy dissipation and pore compression when subjected to external impact energy. The filling of carbon dioxide improves the thermal conductivity and provides the thermal buffering ability of the gas-solid phase, establishing a mechanical-thermal dual-modal energy absorption mechanism; The buffer lubricating phase solves the problem that traditional ceramics are prone to form high friction and local heat accumulation at the contact surface, leading to the expansion of microcracks. Microscopic lubricating layers are constructed using bentonite flakes (peeling layered silicates to form a hydrated layer to provide shear slip) and h-BN nanosheets (solid lubricants, low shear force crystal plane slip), reducing the friction coefficient and wear rate, and buffering the surface shear stress at the same time; The five-phase material forms a multi-phase composite system that does not interfere with each other but is highly cooperative through isostatic pressing and sintering under argon protection. The physical continuity of the material and the functional logic independence are maintained between the components, forming a material architecture of main body load-bearing - self-healing - sensing and warning - impact energy absorption - interface lubrication; Compared with the prior art, the present invention solves the limitation problem of single-functional materials, proposes a composite function path of "self-healing combined with sensing combined with temperature regulation combined with lubrication" in wear-resistant ceramics, provides a new material design paradigm for high-performance structural ceramics, expands the practical application boundary of alumina ceramics in extreme working conditions such as aerospace, high-speed rail transit, and high-pressure seals, and verifies the comprehensive performance superiority of the material in aspects such as microcrack induction, state sensing, impact buffering, and anti-wear and anti-abrasion.

[0038] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wear-resistant alumina ceramic, characterized in that: Comprising the following mass parts ratio: 70 - 80 parts of the main ceramic phase, including α-aluminum oxide, β-aluminum oxide, mullite, and spinel; 8 - 12 parts of the self-healing phase, including nickel-titanium alloy wire, titanium nitride coating, and silicon carbide particles; 1 - 3 parts of the sensing phase, including polydimethylsiloxane capsules, cholesteric liquid crystal mixture, and cerium-doped yttrium aluminum garnet fluorescent particles; 3 - 6 parts of the energy-absorbing and temperature-regulating phase, including metal-organic framework material ZIF-8, metal-organic framework material MIL-101(Fe), and carbon dioxide gas; 1 - 3 parts of the buffer lubricating phase, including bentonite flakes and hexagonal boron nitride nanosheets.

2. A wear-resistant alumina ceramic according to claim 1, characterized in that: Comprising the following mass parts ratio: In the main body ceramic phase: 56-72 parts of α-aluminum oxide (particle size 0.5-2 μm) are selected, 3-6 parts of β-aluminum oxide (particle size 0.3-1 μm) are selected, mullite ( , particle size < 2 μm) 2-4 parts are selected, and spinel ( , particle size < 1 μm) 1-3 parts are selected; In the self-healing phase: 7 - 10 parts of nickel-titanium alloy wire (atomic ratio Ni55Ti45, wire diameter 10 - 30 μm) are selected, 0.5 - 1 part of titanium nitride coating (coating the nickel-titanium alloy wire, coating thickness 100 - 300 nm) is selected, and 0.5 - 1 part of silicon carbide particles (particle size 100 - 300 nm) is selected; In the sensing phase: 0.6 - 2 parts of polydimethylsiloxane capsules (viscosity 500 - 1000 centipoises, mass coating rate ≥ 90%) are selected, 0.2 - 0.7 parts of cholesteric liquid crystal mixture (composed of 7:3 cholesteryl octanoate and cholesteryl heptanoate, color change temperature 25 - 45 °C) are selected, and 0.2 - 0.5 parts of cerium-doped yttrium aluminum garnet fluorescent particles ( , particle size 50 - 200 nanometers) are selected; In the energy-absorbing and temperature-regulating phase: 1-2 parts of metal-organic framework ZIF-8 ( , with a particle size of 100-300 nm) are selected, 1-2 parts of metal-organic framework MIL-101(Fe) ( , with a particle size of 100-300 nm) are selected, and 0.3-0.8 parts of carbon dioxide gas (filled into the pore structures of metal-organic framework ZIF-8 and metal-organic framework MIL-101(Fe)) are selected; In the buffer lubricating phase: 0.5 - 2 parts of bentonite flakes (particle size 1 - 5 μm) are selected, and 0.5 - 1 part of hexagonal boron nitride nanosheets (h-BN, thickness 10 - 100 nm) is selected.

3. A preparation method of a wear-resistant alumina ceramic, comprising applying a wear-resistant alumina ceramic as described in claim 2, wherein: Step 1: Preparation of the raw material mixture of the main ceramic phase: Weigh α-aluminum oxide, β-aluminum oxide, mullite, and spinel according to the preset mass parts ratio, add them to a ball milling device, add a polyvinyl alcohol solution with a mass concentration of 3 - 5% as a dispersant, perform wet ball milling for 12 - 24 hours to obtain the main ceramic phase mixture; Step 2: Preparation of the self-healing phase material: Cut the nickel-titanium alloy wire to a length of 2 - 5 mm, deposit a titanium nitride coating on the surface of the nickel-titanium alloy wire by physical vapor deposition, and uniformly blend the nickel-titanium alloy wire coated with the titanium nitride coating with silicon carbide particles in an ultrasonic dispersion device to obtain the self-healing phase material; Step 3: Preparation of the sensing phase composite material: Dissolve the cholesteric liquid crystal mixture in an organic solvent, and use the micro-droplet emulsification method to coat the cholesteric liquid crystal mixture inside a polydimethylsiloxane capsule with polydimethylsiloxane as the shell material to form a polydimethylsiloxane capsule containing a cholesteric liquid crystal mixture core. Mix the obtained polydimethylsiloxane capsule with cerium-doped yttrium aluminum garnet fluorescent particles under stirring conditions of 100 - 200 rpm to obtain the sensing phase composite material; Step 4: Preparation of the energy-absorbing and temperature-regulating phase composite material: Weigh metal-organic framework ZIF-8 and metal-organic framework MIL-101(Fe) according to the preset mass parts ratio, perform dry mixing for 2 - 4 hours, then place the dry-mixed mixture in a vacuum adsorption device, and fill it with carbon dioxide gas for 12 - 24 hours to obtain the energy-absorbing and temperature-regulating phase composite material; Step 5: Preparation of the buffer lubricating phase composite material: Prepare bentonite flakes by the wet stripping method, prepare hexagonal boron nitride nanosheets by the mechanical stripping method, weigh the bentonite flakes and hexagonal boron nitride nanosheets according to a preset mass fraction ratio, and perform dry mixing for 30 - 60 minutes to obtain a buffer lubricating phase composite material; Step 6: Preparation of the composite ceramic premix: Put the main ceramic phase mixture, self-healing phase material, sensing phase composite material, energy-absorbing and temperature-regulating phase composite material, and buffer lubricating phase composite material into a mixing device according to a preset mass fraction ratio, add a 3% - 5% mass concentration polyvinyl alcohol solution as a temporary binder, and mix for 2 - 4 hours under the condition of a stirring speed of 80 - 150 rpm to obtain a composite ceramic premix; Step 7: Molding of the composite ceramic green body: Place the composite ceramic premix into an isostatic pressing mold, apply a pressure of 150 - 250 MPa, and maintain the pressure for 5 - 10 minutes to form a composite ceramic green body; Step 8: Sintering of the composite ceramic: Place the composite ceramic green body in a sintering furnace under an argon protection atmosphere, heat it to 1450 - 1600 °C at a heating rate of 2 - 5 °C / minute, keep it warm for 2 - 4 hours and then cool it to obtain a sintered composite ceramic material.

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