Multi-element modified aluminum titanate negative thermal expansion ceramic material and preparation method thereof
By preparing multi-element modified aluminum titanate ceramic materials, the problems of easy decomposition of aluminum titanate ceramics at high temperatures and microcrack propagation caused by the anisotropy of thermal expansion coefficient were solved. Stable negative thermal expansion performance and improved mechanical strength at high temperatures were achieved, which are suitable for aerospace and microelectronic chip packaging fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PANZHIHUA UNIV
- Filing Date
- 2026-01-19
- Publication Date
- 2026-04-21
AI Technical Summary
Aluminum titanate ceramics are prone to decomposition into rutile and corundum phases at high temperatures. The anisotropic coefficient of thermal expansion leads to the propagation of microcracks, which weakens mechanical properties. Existing modification techniques are difficult to effectively improve their high-temperature negative thermal expansion properties and mechanical strength.
A multi-element modification method was adopted, in which variable-valence elements such as Fe, Ni, Cr, and Ce were combined with constant-valence elements such as Mg, Zr, and Si, and solid-solid or dispersed in the aluminum titanate matrix. Vanadium extraction tailings were used as the modification raw material to prepare multi-element modified aluminum titanate negative thermal expansion ceramic materials, which were then sintered using a solid-phase synthesis method.
It significantly improves the high-temperature structural stability and mechanical strength of the material, achieves adjustable negative thermal expansion properties, and has good environmental and economic benefits. It is suitable for aerospace, microelectronic chip packaging and other fields.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of negative thermal expansion material preparation technology, specifically relating to a multi-element modified aluminum titanate negative thermal expansion ceramic material and its preparation method. Background Technology
[0002] Negative thermal expansion refers to the phenomenon of lattice contraction in materials when heated. Its "thermal contraction and thermal expansion" characteristic has broad application prospects in precision manufacturing fields such as aerospace, microelectronic chip packaging, sensors, and fiber optic communications. Since the negative thermal expansion properties of ZrW₂O₈ were reported, research on negative thermal expansion materials has gradually become a research hotspot in the field of materials science. Researchers hope to solve the problems caused by the mismatch of thermal expansion coefficients in existing devices through negative thermal expansion materials.
[0003] Among materials with a framework structure and negative thermal expansion, aluminum titanate (Al₂TiO₅) exhibits the most stable structure. Studies have shown that the linear expansion coefficient of polycrystalline aluminum titanate ceramics is only (0.2~1)×10⁻⁶. -6 K -1 The thermal expansion coefficient is significantly lower than that of aluminum titanate single crystals. This is due to the high anisotropy of the thermal expansion coefficients along the three fundamental crystallographic axes, which leads to the formation of numerous microcracks within the Al2TiO5 ceramic system during sintering and cooling. When the temperature rises again, the healing of these microcracks offsets the thermal expansion along the high-expansion crystal axes. Furthermore, due to the large porosity and loose structure within aluminum titanate ceramics, atoms in the crystal can vibrate into the voids within the Al2TiO5 structure as the temperature increases, resulting in overall low thermal expansion behavior by occupying vacancies.
[0004] However, pure aluminum titanate materials easily decompose into rutile and corundum phases at high temperatures (750~1300℃), and the high anisotropy of the coefficient of thermal expansion easily leads to the propagation of microcracks. Although the coefficient of expansion is reduced, the mechanical properties are severely weakened. Therefore, it is particularly important to use modification techniques to strengthen and toughen aluminum titanate ceramics and to control their thermal expansion. Summary of the Invention
[0005] In order to achieve high-temperature negative thermal expansion properties and improve mechanical strength, this invention provides a multi-element modified aluminum titanate negative thermal expansion ceramic material and its preparation method.
[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows.
[0007] In a first aspect, the present invention provides a multi-element modified aluminum titanate negative thermal expansion ceramic material, the microstructure of which includes an aluminum titanate matrix and a modified component composed of at least three foreign elements; the at least three foreign elements are a combination of at least one variable valence element selected from Fe, Ni, Cr, Ce and at least one constant valence element selected from Mg, Zr, Si.
[0008] Furthermore, the modified components described above take at least one of the following forms: The foreign element is dissolved in the crystal lattice of the aluminum titanate matrix; The foreign element forms one or more secondary crystalline phases dispersed in the aluminum titanate matrix.
[0009] Furthermore, the coefficient of thermal expansion of the aforementioned negative thermal expansion ceramic material is -3.00 × 10⁻⁶. -4 ~-1.6×10 -4 K -1 .
[0010] Furthermore, the aforementioned negative thermal expansion ceramic material is either a non-porous dense ceramic or a porous ceramic.
[0011] Furthermore, the density of the aforementioned non-porous dense ceramic is 85-99%.
[0012] Secondly, the present invention provides a method for preparing the above-mentioned multi-element modified aluminum titanate negative thermal expansion ceramic material, comprising the following steps: S1. Raw material weighing and mixing: According to Al 3+ With Ti 4+ The molar ratio of Al2O3 and TiO2 as main raw materials is 2:1. Then, 5-10% of the total mass of the raw materials as modified raw materials are added and mixed to obtain the mixed raw materials. The modified raw material is composed of at least three metal oxides, and the number of moles of metal elements contained in each metal oxide in the modified raw material is equal; the at least three oxides are at least one of Fe oxide, Ni oxide, Cr oxide, and Ce oxide, and a combination of at least one of Mg oxide, Zr oxide, and Si oxide. S2. Ball milling and drying: The mixed raw materials are ball milled and then dried to obtain a mixed powder; S3. Molding: Pressing the mixed powder into a shape to obtain a blank; S4. Sintering: The green body is sintered by first heating it to 400-600℃ at 4-6℃ / min and holding it for 30-60min, then heating it to 1300-1400℃ at 2-3℃ / min, and finally heating it to 1500-1600℃ at 1℃ / min and holding it for 2-4h. After cooling, multi-element modified aluminum titanate negative thermal expansion ceramic material is obtained.
[0013] In step S1 above, an organic pore-forming agent and / or binder are added when weighing the raw materials; the organic pore-forming agent is starch or cellulose, and its addition amount is 0~20% of the total mass of the raw materials; the binder is a polyvinyl alcohol solution with a concentration of 1~5%.
[0014] In step S1 above, the modified raw material is vanadium extraction tailings, whose main components include Fe2O3, Cr2O3, MnO2 and SiO2.
[0015] In step S2 above, the ball milling specifically involves: using ethanol as the ball milling medium, adding grinding balls at a mass ratio of grinding balls, mixed raw materials and ethanol of 1:2:(1~2) for wet ball milling; wherein the ball milling speed is 200~900 rpm and the ball milling time is 6~30 min.
[0016] In step S2 above, the drying conditions are: drying at 40~80℃ for 8~16 hours.
[0017] In step S3 above, the pressing pressure is 15~25MPa, and the holding time is 1~3min.
[0018] The beneficial effects of this invention are as follows: The multi-element modified aluminum titanate ceramic material provided by this invention effectively overcomes the defects of existing aluminum titanate materials, such as the tendency to generate microcracks due to anisotropic thermal expansion and the tendency to undergo phase decomposition at high temperatures, significantly improving the mechanical strength and high-temperature structural stability of the material. Through synergistic doping of specific element combinations, the adjustable coefficient of thermal expansion is achieved, resulting in excellent properties with negative or near-zero thermal expansion. Furthermore, using vanadium extraction tailings as a doping raw material further enhances the material's compressive strength while realizing the resource utilization and high-value utilization of industrial solid waste, achieving both good environmental and economic benefits. The solid-phase synthesis method used in this invention has a simple preparation process with good reproducibility, and the obtained product has high purity and stable performance, possessing the potential for large-scale industrial production. Attached Figure Description
[0019] Figure 1 A schematic diagram of the preparation process of multi-element modified aluminum titanate negative thermal expansion ceramic material; Figure 2 The XRD pattern of the multi-element modified aluminum titanate negative thermal expansion ceramic material prepared in Example 1; Figure 3 EDS elemental distribution diagram of the multi-element modified aluminum titanate negative thermal expansion ceramic material prepared in Example 1; Figure 4 The XRD pattern of the multi-element modified aluminum titanate negative thermal expansion ceramic material prepared in Example 2; Figure 5EDS elemental distribution diagram of the multi-element modified aluminum titanate negative thermal expansion ceramic material prepared in Example 2; Figure 6 The XRD pattern of the multi-element modified aluminum titanate negative thermal expansion ceramic material prepared in Example 3; Figure 7 EDS elemental distribution diagram of the multi-element modified aluminum titanate negative thermal expansion ceramic material prepared in Example 3; Figure 8 The thermal expansion coefficient diagrams of the multi-element modified aluminum titanate negative thermal expansion ceramic materials prepared in Examples 1-3 are compared with those of other doped systems. Figure 9 The compressive strength diagrams of the multi-element modified aluminum titanate negative thermal expansion ceramic materials prepared in Examples 1-3 are compared with other doped systems. Detailed Implementation
[0020] To make the technical problems, solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with the embodiments. Unless otherwise defined, all technical terms used herein have the same meaning as understood by one of ordinary skill in the art.
[0021] This invention provides a multi-element modified aluminum titanate negative thermal expansion ceramic material, the microstructure of which includes an aluminum titanate matrix and a modifying component composed of at least three exogenous elements; the at least three exogenous elements are a combination of at least one variable-valence element selected from Fe, Ni, Cr, and Ce, and at least one constant-valence element selected from Mg, Zr, and Si. The modifying component exhibits the following characteristics: the exogenous elements are solid-dissolved in the crystal lattice of the aluminum titanate matrix; and / or, the exogenous elements form one or more secondary crystalline phases dispersed in the aluminum titanate matrix, thereby synergistically regulating the microstructure and properties of the material.
[0022] Modification using the aforementioned specific multi-element combinations can significantly influence the microstructure and phase composition of aluminum titanate ceramics, effectively overcoming the limitations of single or simple doping. The introduction of variable-valence elements (such as Fe and Ce) makes it possible for the material to exhibit thermal shrinkage at high temperatures; while the addition of constant-valence elements (such as Mg, Si, and Zr) helps stabilize the crystal structure of aluminum titanate, inhibiting its high-temperature decomposition and alleviating anisotropic stress. The synergistic effect of these two elements results in the material exhibiting significant negative thermal expansion characteristics on a macroscopic scale. According to experimental testing, the coefficient of thermal expansion of the multi-element modified aluminum titanate negative thermal expansion ceramic material described in this invention is -3.00 × 10⁻⁶. -4 ~-1.6×10 -4 K -1 .
[0023] In one embodiment of the present invention, the above-mentioned multi-element modified aluminum titanate negative thermal expansion ceramic material can be prepared as a non-porous dense ceramic or a porous ceramic according to actual application needs. Among them, the density of the non-porous dense ceramic can reach 85% to 99%, and it has better mechanical strength and reliability.
[0024] This invention also provides a method for preparing the above-mentioned multi-element modified aluminum titanate negative thermal expansion ceramic material, and the process flow diagram is shown below. Figure 1 As shown, the specific steps include: Press Al 3+ With Ti 4+ Al2O3 and TiO2 were weighed as main raw materials in a molar ratio of 2:1, and then 5-10% of the total mass of the mixed raw materials were added to obtain a mixed raw material. The mixed raw material was ball-milled and dried to obtain a mixed powder. The mixed powder was pressed into a green body to obtain a green body. The green body was sintered. The sintering process was as follows: first, the temperature was raised to 400-600℃ at 4-6℃ / min and held for 30-60min to remove organic matter, then the temperature was raised to 1300-1400℃ at 2-3℃ / min, and finally the temperature was raised to 1500-1600℃ at 1℃ / min and held for 2-4h, and then cooled to obtain a multi-element modified aluminum titanate negative thermal expansion ceramic material.
[0025] In one embodiment of the present invention, the modified raw material is composed of at least three single metal oxides, and the number of moles of metal elements in each oxide is equal; the at least three oxides are selected from the following two categories: the first category is oxides of at least one element selected from Fe, Ni, Cr, and Ce, and the second category is oxides of at least one element selected from Mg, Zr, and Si.
[0026] In one embodiment of the present invention, the modified raw material is vanadium extraction tailings, whose main components include Fe2O3, Cr2O3, TiO2, MnO2, SiO2, Al2O3, etc. Vanadium extraction tailings are solid waste generated during vanadium smelting. The present invention uses them as a dopant source, not only realizing the resource utilization of solid waste, but also, due to the presence of multiple elements with varying and constant valence, synergistically improving material properties. Experiments show that ceramic materials prepared using vanadium extraction tailings as a modified raw material have significantly higher compressive strength than unmodified alumina titanate ceramics, and are superior to most pure oxide doped systems with the same addition amount. This indicates that the complex components in vanadium extraction tailings may produce further synergistic enhancement effects.
[0027] In one embodiment of the present invention, an organic pore-forming agent and / or binder may be added when weighing the raw materials. The organic pore-forming agent may be selected from starch or cellulose, and its addition amount is 0-20% of the total mass of the mixed raw materials. It is used to form pores during subsequent sintering to prepare porous ceramics; when preparing non-porous dense ceramics, the organic pore-forming agent may not be added. The use of the binder is a conventional technique in ceramic forming in the art. The binder is a polyvinyl alcohol (PVA) solution, and its concentration is generally 1-5 wt%. The addition amount can be adjusted according to the forming process requirements to facilitate the forming of the green body.
[0028] In one embodiment of the present invention, the ball milling specifically involves: using ethanol as the milling medium, adding milling balls at a mass ratio of 1:2:(1~2) of milling balls, mixed raw materials, and ethanol, and performing wet ball milling; wherein the ball milling speed is 200~900 rpm, and the milling time is 6~30 min. The milled raw materials are dried at 40~80℃ for 8~16 h to obtain a mixed powder.
[0029] In one embodiment of the present invention, the mixed powder is pressed into shape under a pressure of 15~25MPa and held under pressure for 1~3min to obtain a blank.
[0030] The following specific embodiments will be provided to explain the solution of the present invention. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.
[0031] Example 1: Preparation of iron-magnesium-zirconium-silicon-cerium modified aluminum titanate ceramics, the specific steps are as follows.
[0032] (1) Raw material ratio and preparation 0.1 mol of Al₂O₃ and TiO₂ were weighed as the main raw materials. Oxide powders of five elements—Fe, Mg, Zr, Si, and Ce—were weighed as modifying raw materials, with equal molar amounts of each metal element in each modified oxide. Two samples with different amounts of modified raw materials were prepared in this example: one with a total added amount of 5 wt% of the total solid raw material mass; and the other with a total added amount of 10 wt%. Starch was also weighed as an organic pore-forming agent, with an added amount of 10 wt% of the total solid raw material mass. Subsequently, 3 drops of a 1% (w / w) PVA solution were added to the mixture as a binder.
[0033] All the above raw materials were placed in a 500mL zirconia ball mill jar, 10mL ethanol and 9.55g zirconia grinding balls (3mm in diameter) were added, and the mixture was ball-milled at 600rpm for 12min. The ball-milled material was dried at 80℃ for 8h, and the resulting powder was pressed into a green body under a pressure of 20MPa (holding pressure for 2min). The green body was sintered: the temperature was increased to 500℃ at 5℃ / min and held for 30min; then increased to 1380℃ at 2℃ / min; finally, the temperature was increased to 1550℃ at 1℃ / min and held for 2h to complete the sintering. After cooling, iron-magnesium-zirconia-silicon-cerium modified aluminum titanate ceramics were obtained.
[0034] (2) Structural characterization and analysis Figure 2 The XRD pattern of the iron-magnesium-zirconium-silicon-cerium modified aluminum titanate ceramic is shown in the figure. As can be seen, the XRD pattern of the modified material is basically consistent with that of the unmodified aluminum titanate ceramic, with aluminum titanate as the main crystalline phase, indicating that the introduction of the modifying elements did not change the main crystal structure of aluminum titanate. Only diffraction peaks belonging to Al2TiO5, a small amount of Al2O3, and CeO2 were observed in the spectrum; no independent oxide crystalline phases of Fe, Mg, Zr, Si, etc., were detected. This indicates that Fe, Mg, Zr, Si, etc., have dissolved into the aluminum titanate lattice during the sintering process; while some Ce elements exist as a dispersed CeO2 phase. It is noteworthy that no independent Zr-containing phase peaks were observed in the XRD pattern. Combined with the analysis of the sizing ratio and reaction system, Zr elements may exist in the material through solid solution or by forming an amorphous phase. Further elemental surface distribution analysis was performed using energy dispersive spectroscopy (EDS), and the results are as follows... Figure 3 As shown in the figure, Fe, Mg, Si, and Ce are all uniformly distributed in the ceramic matrix. Although Zr is not clearly visible in the surface distribution diagram due to its weak characteristic X-ray signal, combined with the aforementioned XRD analysis and raw material ratio, it can be confirmed that Zr has participated in the material composition and achieved uniform distribution. These results collectively confirm that this embodiment achieves uniform modification and compositing of multiple elements at both the atomic and micron scales.
[0035] Example 2: Preparation of iron-nickel-magnesium-cerium-silicon-zirconium-chromium modified aluminum titanate ceramics, the specific steps are as follows.
[0036] (1) Raw material ratio and preparation 0.1 mol of Al₂O₃ and TiO₂ were weighed as the main raw materials. Oxide powders of seven elements—Fe, Ni, Mg, Ce, Si, Zr, and Cr—were weighed as modifying raw materials, with equal molar amounts of each metal element in each modified oxide. Two samples with different amounts of modified raw materials were prepared in this example: one with a total added amount of 5 wt% of the total mass of all solid raw materials; and the other with a total added amount of 10 wt%. Starch was also weighed as an organic pore-forming agent, with an added amount of 10 wt% of the total mass of all solid raw materials. Subsequently, two drops of a 1% (w / w) PVA solution were added to the mixture as a binder.
[0037] All the above raw materials were placed in a 500mL zirconia ball mill jar, and 25mL of ethanol and 20g of zirconia grinding balls (3mm in diameter) were added. The mixture was ball-milled at 200rpm for 30min. The ball-milled material was dried at 60℃ for 16h, and the resulting powder was pressed into a green body under a pressure of 15MPa (holding pressure for 3min). The green body was then sintered: the temperature was increased to 500℃ at 5℃ / min and held for 40min; then increased to 1300℃ at 2℃ / min; and finally increased to 1600℃ at 1℃ / min and held for 2h to complete the sintering. After cooling, iron-nickel-magnesium-cerium-silicon-zirconium-chromium modified aluminum titanate ceramics were obtained.
[0038] (2) Structural characterization and analysis Figure 4 The XRD pattern of the iron-nickel-magnesium-cerium-silicon-zirconium-chromium modified aluminum titanate ceramic is shown in the figure. As can be seen from the figure, the main crystalline phase of the modified material is aluminum titanate, and Al₂O₃, Ce(Zr₂O₇) and Al₂O₃ are also detected. 1.54 Cr 0.46 The diffraction peaks of O3 did not detect independent oxide crystalline phases of elements such as Fe, Mg, and Si. This indicates that elements such as Fe, Ni, Mg, and Si have been dissolved into the aluminum titanate lattice during the sintering process. Further elemental surface distribution analysis using energy dispersive spectroscopy yielded the following results: Figure 5 As shown in the figure, Fe, Ni, Mg, Ce, Si, and Cr are all uniformly distributed in the ceramic matrix. Although Zr is not clearly visible in the surface distribution diagram due to its weak characteristic X-ray signal, the XRD pattern shows its participation in the Ce(Zr₂O₇) compound phase. Combined with the raw material ratio, it can be confirmed that Zr has participated in the material composition and achieved uniform distribution. These results collectively confirm that this embodiment achieves uniform doping and recombination of multiple elements at both the atomic and micron scales.
[0039] Example 3: Preparation of vanadium tailings modified aluminum titanate ceramics, the specific steps are as follows.
[0040] (1) Raw material ratio and preparation 0.1 mol of Al₂O₃ and TiO₂ were weighed as the main raw materials. Vanadium extraction tailings were weighed as the modifying raw material. In this embodiment, two samples with different amounts of modified raw materials were prepared: one with a total amount of modified raw materials of 5 wt% of the total mass of all solid raw materials; and the other with a total amount of modified raw materials of 10 wt%. Subsequently, 5 drops of 1% PVA solution were added to the mixture as a binder.
[0041] All the above raw materials were placed in a 500mL zirconia ball mill jar, 15mL ethanol and 9.55g zirconia grinding balls (3mm in diameter) were added, and the mixture was ball-milled at 900rpm for 10min. The ball-milled material was dried at 40℃ for 16h, and the resulting powder was pressed into a green body under a pressure of 25MPa (holding pressure for 1min). The green body was sintered: the temperature was increased to 500℃ at 5℃ / min and held for 60min; then increased to 1400℃ at 2℃ / min; finally increased to 1500℃ at 1℃ / min and held for 4h to complete the sintering. After cooling, vanadium tailings modified aluminum titanate ceramics were obtained.
[0042] (2) Structural characterization and analysis Figure 6 The XRD pattern of the vanadium extraction tailings modified aluminum titanate ceramic is shown in the figure. As can be seen from the figure, the main crystalline phase of the modified material is aluminum titanate, and SiO2, ZrO2, MgO, and Al are also detected. 1.98 Cr 0.02 The diffraction peaks of O3 and FeSiO4 indicate that multiple components in the vanadium extraction tailings participated in the reaction during sintering, forming a multiphase composite ceramic material. Further elemental surface distribution analysis using energy dispersive spectroscopy yielded the following results: Figure 7 As shown in the figure, Fe, Mn, Si, and Cr are all uniformly distributed in the ceramic matrix. These results collectively confirm that this embodiment utilizes vanadium extraction tailings to achieve uniform modification and composite composition of multiple elements.
[0043] Example 4: Performance Testing of Multi-element Modified Aluminum Titanate Negative Thermal Expansion Ceramic Material (1) The aluminum titanate ceramic materials with different doping and modification systems were tested using a thermal expansion meter (NETZSCH DIL 402C), and the results are as follows: Figure 8As shown, comparing the materials of undoped, simply doped (iron-nickel, iron-nickel-chromium) and Examples 1 (variable valence element doping), 2 (multi-element doping), and 3 (vanadium extraction tailings doping) of this invention, it can be seen that: the undoped and simply doped systems only exhibit brief negative expansion in the low-temperature range (200~400℃), which then turns into positive expansion as the temperature increases; while the materials of each example of this invention exhibit continuous negative expansion behavior within the test temperature range. Specifically, the expansion curves of the materials of Examples 1 and 2 are in the negative range throughout, while the material of Example 3, although showing a recovery trend in the high-temperature range, always maintains negative expansion. The above results indicate that the multi-element synergistic doping modification described in this invention can effectively control and achieve stable negative thermal expansion performance of materials in a wide temperature range.
[0044] (2) The compressive strength of aluminum titanate ceramic materials with different doping and modification systems was tested, and the results are as follows: Figure 9 As shown in the figure. Tests show that the compressive strength of all doped modified systems is significantly higher than that of undoped modified aluminum titanate ceramics. With the same amount of modifying raw materials, the multi-element doped modified systems corresponding to Examples 1 and 2 of this invention exhibit significantly better strength than simple iron-nickel or iron-nickel-chromium doped systems. Among them, the material in Example 3, which uses vanadium extraction tailings as the modifying raw material, shows the highest compressive strength, increasing by more than 50% compared to the undoped modified material at the preferred amount of modifying raw materials. This confirms the enhancing effect of multi-element doping modification on mechanical properties of this invention, and the synergistic effect of the complex components in the vanadium extraction tailings further improves the compressive strength of the material.
Claims
1. A multi-element modified aluminum titanate negative thermal expansion ceramic material, characterized in that: Its microstructure includes an aluminum titanate matrix and a modified component consisting of at least three foreign elements; the at least three foreign elements are a combination of at least one variable valence element selected from Fe, Ni, Cr, Ce and at least one constant valence element selected from Mg, Zr, Si.
2. The multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 1, characterized in that, The modified component is manifested in at least one of the following forms: The foreign element is dissolved in the crystal lattice of the aluminum titanate matrix; The foreign element forms one or more secondary crystalline phases dispersed in the aluminum titanate matrix.
3. The multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 1 or 2, characterized in that: The coefficient of thermal expansion of the ceramic material is -3.00 × 10⁻⁶. -4 ~-1.6×10 -4 K -1 .
4. The multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 1 or 2, characterized in that: The ceramic material is either non-porous dense ceramic or porous ceramic.
5. The multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 4, characterized in that: The density of the non-porous dense ceramic is 85-99%.
6. The method for preparing the multi-element modified aluminum titanate negative thermal expansion ceramic material according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Raw material weighing and mixing: According to Al 3+ With Ti 4+ The molar ratio of Al2O3 and TiO2 as main raw materials is 2:
1. Then, 5-10% of the total mass of the raw materials as modified raw materials are added and mixed to obtain a mixed raw material. The modified raw material is composed of at least three metal oxides, and the number of moles of metal elements contained in each metal oxide in the modified raw material is equal; the at least three oxides are at least one of Fe oxide, Ni oxide, Cr oxide, and Ce oxide, and a combination of at least one of Mg oxide, Zr oxide, and Si oxide. S2. Ball milling and drying: The mixed raw materials are ball milled and then dried to obtain a mixed powder; S3. Molding: Pressing the mixed powder into a shape to obtain a blank; S4. Sintering: The green body is sintered by first heating it to 400-600℃ at 4-6℃ / min and holding it for 30-60min, then heating it to 1300-1400℃ at 2-3℃ / min, and finally heating it to 1500-1600℃ at 1℃ / min and holding it for 2-4h. After cooling, multi-element modified aluminum titanate negative thermal expansion ceramic material is obtained.
7. The preparation method of the multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 6, characterized in that: In step S1, an organic pore-forming agent and / or binder are added when weighing the raw materials; The organic pore-forming agent is starch or cellulose, and its addition amount is 0-20% of the total mass of the raw materials; The adhesive is a polyvinyl alcohol solution with a concentration of 1-5%.
8. The preparation method of the multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 6, characterized in that: In step S1, the modified raw material is vanadium extraction tailings, whose main components include Fe2O3, Cr2O3, MnO2 and SiO2.
9. The preparation method of the multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 6, characterized in that: In step S2, the ball milling specifically involves: using ethanol as the ball milling medium, adding grinding balls at a mass ratio of grinding balls, mixed raw materials, and ethanol of 1:2:(1~2) for wet ball milling; wherein the ball milling speed is 200~900 rpm and the ball milling time is 6~30 min; In step S2, the drying conditions are: drying at 40~80℃ for 8~16 hours.
10. The preparation method of the multi-element modified aluminum titanate negative thermal expansion ceramic material according to claim 6, characterized in that: In step S3, the pressing pressure is 15~25MPa, and the holding time is 1~3min.