Preparation method of aluminum titanate honeycomb ceramic

Abstract

The invention discloses an aluminum titanate honeycomb ceramic preparation method, and relates to the technical field of ceramic preparation, and the method comprises the following operation steps: S1, weighing required raw materials: aluminum titanate powder, mullite fiber, alumina micro powder, magnesium oxide, yttrium oxide and a binder; s2, adding the raw materials into a ball mill, and sieving after ball milling to obtain mixed powder; s3, adding a lubricant into the mixed powder, kneading into pug, carrying out degassing treatment in a vacuum pug mill, and then carrying out extrusion forming to obtain a honeycomb ceramic green body; and S4, drying the honeycomb ceramic green body, and sintering to obtain the aluminum titanate honeycomb ceramic. By adding the mullite fibers and optimizing the raw material formula and the preparation process, the mechanical strength and thermal stability of the aluminum titanate honeycomb ceramic are remarkably improved, the thermal expansion coefficient is reduced, the aluminum titanate honeycomb ceramic can stably work for a long time in a high-temperature environment, meanwhile, the preparation method effectively prevents the aluminum titanate ceramic from cracking in the preparation process, and the service life of the aluminum titanate honeycomb ceramic is prolonged. And the finished product strength is obviously improved.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic preparation, in particular to a method for preparing aluminum titanate honeycomb ceramics. Background Art

[0002] In high-temperature industrial fields, such as automobile exhaust purification and industrial furnace heat exchange, ceramic materials play a vital role. However, these application scenarios place extremely high demands on the thermal stability and low thermal expansion coefficient of ceramic materials. In this context, aluminum titanate ceramics stand out due to their unique low thermal expansion properties and become a high-temperature structural material with great potential.

[0003] The low thermal expansion properties of aluminum titanate ceramics enable them to maintain stable size and shape in high temperature environments, thus ensuring long-term stable operation of equipment. However, despite the many advantages of aluminum titanate ceramics, the traditional preparation process limits their widespread application. During the preparation process, aluminum titanate ceramics are prone to cracking, and the finished product has low strength. These problems have greatly affected its performance in practical applications. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing aluminum titanate honeycomb ceramics to solve the technical problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing aluminum titanate honeycomb ceramics, comprising the following steps:

[0006] S1. Weigh the required raw materials: aluminum titanate powder, mullite fiber, alumina powder, magnesium oxide, yttrium oxide and binder;

[0007] S2, adding the above raw materials into a ball mill, sieving after ball milling to obtain a mixed powder;

[0008] S3, adding a lubricant to the mixed powder and kneading it into a mud material, and degassing it in a vacuum mud kneading machine, and then extruding it to obtain a honeycomb ceramic body;

[0009] S4, drying the honeycomb ceramic body, and then sintering it to obtain aluminum titanate honeycomb ceramics.

[0010] Preferably, the aluminum titanate honeycomb ceramic in S1 is composed of the following raw materials in percentage by mass: 70-80% aluminum titanate powder, 5-10% mullite fiber, 5-10% alumina powder, 2-5% magnesium oxide, 1-3% yttrium oxide, and 3-5% binder.

[0011] Preferably, the average particle size of the aluminum titanate powder in S1 is 1-5 μm, and the length of the mullite fiber is 100-500 μm and the diameter is 5-10 μm.

[0012] Preferably, the binder in S1 is hydroxypropyl methylcellulose, polyvinyl alcohol or a mixture of the two.

[0013] Preferably, the time required for ball milling in S1 is 8-12 hours, and the device used for screening is a vibrating screen to achieve rapid screening and mixing.

[0014] Preferably, the equipment used for kneading in S2 is a kneader, so that the mixed powder and the lubricant can be quickly mixed to form a mud material.

[0015] Preferably, the equipment used for the extrusion molding in S2 is an extrusion molding machine, so that the mud material can be quickly formed into a ceramic body with a honeycomb structure.

[0016] Preferably, the drying temperature required for the honeycomb ceramic green body in S3 is 80-120° C., and the drying time is 12-24 hours.

[0017] Preferably, the temperature required for sintering the honeycomb ceramic green body after drying in S3 is 1400-1500° C., and the sintering time required is 3-5 hours.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The invention significantly improves the mechanical strength and thermal stability of aluminum titanate honeycomb ceramics and reduces the thermal expansion coefficient by adding mullite fibers and optimizing the raw material formula and preparation process, so that the aluminum titanate honeycomb ceramics can work stably for a long time in a high temperature environment. At the same time, the preparation method effectively prevents the aluminum titanate ceramics from cracking during the preparation process, and the strength of the finished product is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic flow chart of the method for preparing aluminum titanate honeycomb ceramics of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Embodiment 1

[0023] See also Figure 1 The present invention provides a technical solution: a method for preparing aluminum titanate honeycomb ceramics, comprising the following steps:

[0024] S1. Weigh 75kg of aluminum titanate powder, 8kg of mullite fiber, 8kg of alumina powder, 3kg of magnesium oxide, 2kg of yttrium oxide, and 4kg of sodium carboxymethyl cellulose. The average particle size of the aluminum titanate powder is 1-5μm, the length of the mullite fiber is 100-500μm, and the diameter is 5-10μm. The binder is hydroxypropyl methylcellulose, polyvinyl alcohol, or a mixture of the two.

[0025] S2, adding aluminum titanate powder, mullite fiber, alumina powder, magnesium oxide, yttrium oxide and a binder into a ball mill, sieving after ball milling for 10 hours to obtain a mixed powder, and the equipment used for sieving is a vibrating screen, so as to achieve rapid screening and mixing, and the screening and mixing efficiency and production efficiency are high;

[0026] S3, kneading the mixed powder into a mud material with a lubricant, and degassing the mixed powder in a vacuum mud kneading machine, and then extruding the mixed powder into a mud material to obtain a honeycomb ceramic body. The equipment used for kneading is a kneading machine, so that the mixed powder and the lubricant are quickly mixed to form a mud material, and the equipment used for extrusion molding is an extrusion molding machine, so that the mud material is quickly formed into a ceramic body with a honeycomb structure, and the size accuracy is high and the surface quality is good;

[0027] S4, drying the honeycomb ceramic green body at 100° C. for 14 hours, and then sintering it at 1450° C. for 4 hours to obtain aluminum titanate honeycomb ceramic.

[0028] The thermal expansion coefficient of the aluminum titanate honeycomb ceramic prepared in this embodiment is 0.8×10 -6 / ℃, the compressive strength is 35MPa. After 5 consecutive experiments at room temperature of 350℃, the strength retention rate is 95%, and the change rate of thermal expansion coefficient is less than 1%.

[0029] Embodiment 2

[0030] See also Figure 1 The present invention provides a technical solution: a method for preparing aluminum titanate honeycomb ceramics, comprising the following steps:

[0031] S1. Weigh 80 kg of aluminum titanate powder, 5 kg of mullite fiber, 5 kg of alumina powder, 4 kg of magnesium oxide, 3 kg of yttrium oxide, and 3 kg of polyvinyl alcohol. The average particle size of the aluminum titanate powder is 1-5 μm, the length of the mullite fiber is 100-500 μm, and the diameter is 5-10 μm. The binder is hydroxypropyl methylcellulose, polyvinyl alcohol, or a mixture of the two.

[0032] S2, adding aluminum titanate powder, mullite fiber, alumina powder, magnesium oxide, yttrium oxide and a binder into a ball mill, and sieving after ball milling for 12 hours to obtain a mixed powder, and the equipment used for sieving is a vibrating screen, so as to achieve rapid screening and mixing, and the screening and mixing efficiency and production efficiency are high;

[0033] S3, kneading the mixed powder into a mud material with a lubricant, and degassing the mixed powder in a vacuum mud kneading machine, and then extruding the mixed powder into a mud material to obtain a honeycomb ceramic body. The equipment used for kneading is a kneading machine, so that the mixed powder and the lubricant are quickly mixed to form a mud material, and the equipment used for extrusion molding is an extrusion molding machine, so that the mud material is quickly formed into a ceramic body with a honeycomb structure, and the size accuracy is high and the surface quality is good;

[0034] S4, drying the honeycomb ceramic body at 120° C. for 12 hours, and then sintering at 1500° C. for 3 hours to obtain aluminum titanate honeycomb ceramics.

[0035] The thermal expansion coefficient of the aluminum titanate honeycomb ceramic prepared in this embodiment is 0.7×10 -6 / ℃, the compressive strength is 38MPa. After 5 consecutive experiments at room temperature of 350℃, the strength retention rate is 92% and the change rate of thermal expansion coefficient is less than 1%.

[0036] Embodiment 3

[0037] See also Figure 1 The present invention provides a technical solution: a method for preparing aluminum titanate honeycomb ceramics, comprising the following steps:

[0038] S1. Weigh 70 kg of aluminum titanate powder, 10 kg of mullite fiber, 10 kg of alumina powder, 2 kg of magnesium oxide, 1 kg of yttrium oxide, 2 kg of sodium carboxymethyl cellulose, and 2 kg of polyvinyl alcohol. The average particle size of the aluminum titanate powder is 1-5 μm, the length of the mullite fiber is 100-500 μm, and the diameter is 5-10 μm. The binder is hydroxypropyl methylcellulose, polyvinyl alcohol, or a mixture of the two.

[0039] S2, adding aluminum titanate powder, mullite fiber, alumina powder, magnesium oxide, yttrium oxide and a binder into a ball mill, sieving after ball milling for 8 hours to obtain a mixed powder, and the equipment used for sieving is a vibrating screen, so as to achieve rapid screening and mixing, and the screening and mixing efficiency and production efficiency are high;

[0040] S3, kneading the mixed powder into a mud material with a lubricant, and degassing the mixed powder in a vacuum mud kneading machine, and then extruding the mixed powder into a mud material to obtain a honeycomb ceramic body. The equipment used for kneading is a kneading machine, so that the mixed powder and the lubricant are quickly mixed to form a mud material, and the equipment used for extrusion molding is an extrusion molding machine, so that the mud material is quickly formed into a ceramic body with a honeycomb structure, and the size accuracy is high and the surface quality is good;

[0041] S4, drying the honeycomb ceramic body at 80° C. for 24 hours, and then sintering at 1400° C. for 5 hours to obtain aluminum titanate honeycomb ceramics.

[0042] The thermal expansion coefficient of the aluminum titanate honeycomb ceramic prepared in this embodiment is 0.9×10 -6 / ℃, the compressive strength is 32MPa. After 5 consecutive experiments at room temperature of 350℃, the strength retention rate is 90% and the change rate of thermal expansion coefficient is less than 1%.

[0043] To sum up: when using the preparation method of aluminum titanate honeycomb ceramics, a certain amount of aluminum titanate powder, mullite fiber, alumina powder, magnesium oxide, yttrium oxide, and sodium carboxymethyl cellulose are weighed, and then the aluminum titanate powder, mullite fiber, alumina powder, magnesium oxide, yttrium oxide and binder are added to a ball mill, and sieved after ball milling to obtain a mixed powder, and the equipment used for sieving is a vibrating screen to achieve rapid screening and mixing. At this time, the mixed powder is kneaded into a mud material with a lubricant, and degassing treatment is carried out in a vacuum mud kneading machine, and then a honeycomb ceramic body is obtained by extrusion molding, and the equipment used for kneading is a kneading machine, so that the mixed powder and the lubricant are quickly mixed to form mud, and the equipment used for extrusion molding is an extrusion molding machine, so that the mud can quickly form a ceramic body with a honeycomb structure, and after the honeycomb ceramic body is dried, the dried honeycomb ceramic body is sintered to obtain aluminum titanate honeycomb ceramics. The contents not described in detail in this description belong to the prior art known to professional and technical personnel in this field.

[0044] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing aluminum titanate honeycomb ceramics, characterized in that: The steps are as follows: S1. Weigh the required raw materials: aluminum titanate powder, mullite fiber, alumina powder, magnesium oxide, yttrium oxide and binder; S2, adding the above raw materials into a ball mill, sieving after ball milling to obtain a mixed powder; S3, adding a lubricant to the mixed powder and kneading it into a mud material, and degassing it in a vacuum mud kneading machine, and then extruding it to obtain a honeycomb ceramic body; S4, drying the honeycomb ceramic body, and then sintering it to obtain aluminum titanate honeycomb ceramics.

2. The method for preparing aluminum titanate honeycomb ceramics according to claim 1, characterized in that: The aluminum titanate honeycomb ceramic in S1 is composed of the following raw materials in percentage by mass: 70-80% aluminum titanate powder, 5-10% mullite fiber, 5-10% alumina powder, 2-5% magnesium oxide, 1-3% yttrium oxide, and 3-5% binder.

3. The method for preparing aluminum titanate honeycomb ceramics according to claim 2, characterized in that: The average particle size of the aluminum titanate powder in S1 is 1-5 μm, the length of the mullite fiber is 100-500 μm, and the diameter is 5-10 μm.

4. The method for preparing aluminum titanate honeycomb ceramics according to claim 2, characterized in that: The binder in S1 is hydroxypropyl methylcellulose, polyvinyl alcohol or a mixture of the two.

5. The method for preparing aluminum titanate honeycomb ceramics according to claim 1, characterized in that: The time required for ball milling in S1 is 8-12 hours, and the device used for screening is a vibrating screen to achieve rapid screening and mixing.

6. The method for preparing aluminum titanate honeycomb ceramics according to claim 1, characterized in that: The equipment used for kneading in S2 is a kneader, so that the mixed powder and the lubricant are quickly mixed to form a mud material.

7. The method for preparing aluminum titanate honeycomb ceramics according to claim 6, characterized in that: The equipment used for the extrusion molding in S2 is an extrusion molding machine, so that the mud material can be quickly formed into a ceramic body with a honeycomb structure.

8. The method for preparing aluminum titanate honeycomb ceramics according to claim 1, characterized in that: The drying temperature required for the honeycomb ceramic green body in S3 is 80-120° C., and the drying time is 12-24 hours.

9. The method for preparing aluminum titanate honeycomb ceramics according to claim 8, characterized in that: The temperature required for sintering the honeycomb ceramic green body dried in S3 is 1400-1500° C., and the sintering time required is 3-5 hours.

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