Novel ceramic fiber blanket and preparation method thereof

Abstract

The invention relates to the technical field of fiber blankets, in particular to a novel ceramic fiber blanket and a preparation method thereof. The preparation method comprises the following steps: step a, uniformly mixing aluminum oxide powder, silicon oxide powder and magnesium oxide, and heating at high temperature to obtain a solution; b, adding a binder into the solution, and adjusting the viscosity of the molten solution; c, adding the solution into a spinning cylinder, heating under the protection of nitrogen, standing, cooling, and spinning into fibers; d, adding the prepared fibers into a forming machine to obtain a semi-finished product of the fiber blanket; and e, carrying out high-temperature heat treatment on the fiber blanket half according to a certain procedure. By improving the added raw material composition, the binder and the high-temperature heat treatment procedure, the novel high-temperature-resistant and tensile ceramic fiber blanket is provided, and the problem that an existing production process is unstable is solved.

Description

Technical Field

[0001] The invention relates to the technical field of fiber blankets, and in particular to a novel ceramic fiber blanket and a preparation method thereof. Background Art

[0002] Ceramic fiber has certain mechanical strength and high temperature resistance, and is widely used in petrochemical, national defense, military industry, aerospace and other fields. Alumina fiber is a new type of high-performance ceramic fiber, the main component of which is Al 2 O 3 , so the ceramic fiber blanket is also called aluminum silicate fiber blanket. Alumina fibers are divided into short fibers, whiskers and continuous fibers. Continuous ceramic fibers have continuous length, uninterrupted fiber morphology, long length, uniform performance and structure, and can be wound and woven into two-dimensional and three-dimensional preforms. Continuous alumina fibers are mainly produced by high-temperature melting, wire drawing, cooling and solidification. Compared with other ceramic fibers such as carbide fibers and nitride fibers, alumina ceramic fibers have the advantages of easy availability of raw materials, relatively low production equipment requirements, and no need for inert gas protection during sintering.

[0003] Patent document No. CN 118514183A discloses a method for preparing a ceramic fiber blanket and a composite high-strength ceramic fiber blanket, wherein the preparation method includes a molding process, a first cutting process, an assembly process, a second cutting process, and a packaging process. The invention solves the problem of a large amount of waste generated during the production process of existing ceramic blankets and mismatched molding structures. However, the ceramic fiber blankets currently still have problems such as low maturity of overall engineering technology and unstable production processes. Summary of the invention

[0004] In view of the problems existing in the background technology, the present invention provides a new type of ceramic fiber blanket that is resistant to high temperature and tensile strength by improving the composition of added raw materials, binders and high-temperature heat treatment procedures, which is achieved through the following technical solutions:

[0005] A method for preparing a novel ceramic fiber blanket comprises the following steps:

[0006] Step a: adding aluminum oxide powder, silicon oxide powder and magnesium oxide in proportions, mixing evenly, and heating at high temperature to obtain a solution;

[0007] Step b: adding a binder to the melt to adjust the viscosity of the molten solution;

[0008] Step c: adding the above solution into a spinning cylinder, heating it under nitrogen protection, cooling it down after standing, and spinning it into fibers;

[0009] Step d: adding the prepared fibers into a forming machine to obtain a semi-finished fiber blanket;

[0010] Step e: placing the fiber blanket semi-finished product into a TL1200-12001 resistance tube furnace and performing high temperature heat treatment in a nitrogen atmosphere according to a certain procedure;

[0011] The proportions are 65-75 parts of aluminum oxide powder, 20-25 parts of silicon oxide powder, 5-15 parts of magnesium oxide, and 1-4 parts of binder.

[0012] Preferably, the average particle size of the aluminum oxide and silicon oxide powders is 1 μm to 3 μm.

[0013] Preferably, in step a, the high temperature melting temperature is 1200° C. and the melting time is 1 to 2 hours.

[0014] The method for preparing a novel ceramic fiber blanket according to claim 1 is characterized in that the binder is 15wt% polyvinyl pyrrolidone.

[0015] Preferably, the operation of step c is: adding the above solution to a spinning cylinder, heating to 550°C under nitrogen protection, standing for 0.5 hours for degassing, then lowering the temperature to 400°C, setting the rotation speed of the spinning cylinder to 400r / min, and spinning into fibers.

[0016] Preferably, in the step d, the fibers obtained in step c are added to a cotton collector and a conveyor belt is used to convey the fiber filaments to a roller press for roller pressing, and then the formed fiber blanket is conveyed to a needle punching machine for needle punching to obtain a semi-finished fiber blanket.

[0017] Preferably, the procedure for high temperature heat treatment in step e is: in a nitrogen atmosphere, the temperature of the first section is set to rise from room temperature to 300-350°C at a rate of 5-10°C / min, and kept warm for 1-1.5 hours; the temperature of the second section is set to rise from 300-350°C to 550-700°C at a rate of 10-15°C / min, and kept warm for 1-2 hours; the temperature of the third section is set to rise from 550-700°C to 950-1050°C at a rate of 10-15°C / min, and kept warm for 0.5-1 hour.

[0018] Preferably, the thickness of the molded fiber blanket is 200-300 mm.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a novel ceramic fiber blanket and a preparation method thereof. The tensile strength of the single-filament fiber of the prepared fiber gradually increases with the increase of the concentration of polyvinyl pyrrolidone added. The tensile strength is the highest when the concentration of polyvinyl pyrrolidone is 17wt%, reaching 2.35GPa. With the increase of temperature, the structure of the fiber remains dense after treatment at 1200°C, and the tensile strength of the fiber is 1.55GPa. The tensile strength of the fiber made into a ceramic fiber blanket is 19-23GPa, which is significantly improved compared with the fiber monofilament, and the change pattern is consistent with the fiber monofilament. The temperature resistance of the prepared ceramic fiber blanket is between 1300 and 1450°C, which meets general industrial needs. In addition, in the present invention, a slight change in the production process has no obvious effect on the performance of the ceramic blanket. DETAILED DESCRIPTION

[0021] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0022] It should be noted that the experimental methods used in the implementation examples are all conventional methods unless otherwise specified; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0023] In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined with each other to form a new technical solution.

[0024] Embodiment 1;

[0025] Add 66 parts of aluminum oxide powder with an average particle size of 1μm to 3μm, 21 parts of silicon oxide powder, and 11 parts of magnesium oxide, mix well, and melt at a high temperature of 1200°C for 2 hours to obtain a solution; add 2 parts of 15wt% polyvinyl pyrrolidone to the solution to adjust the viscosity of the molten solution; add the above solution to a spinning cylinder, heat to 550°C under nitrogen protection, stand for 0.5 hour to degas, then reduce the temperature to 400°C, set the rotation speed of the spinning cylinder to 400r / min, spin into fibers, and obtain fiber a.

[0026] The fibers obtained above are added to the conveyor belt in the cotton collector to convey the fiber filaments to the roller press for rolling, and then the formed fiber blanket is conveyed to the needle punching machine for needle punching to obtain a fiber blanket semi-finished product. The fiber blanket semi-finished product is placed in a TL1200-12001 resistance tube furnace, and the temperature of the first section is set to increase from room temperature to 300°C at a rate of 5-10°C / min under a nitrogen atmosphere, and keep warm for 1 hour; the temperature of the second section is increased from 300°C to 550°C at a rate of 10-15°C / min, and kept warm for 1 hour; the temperature of the third section is increased from 550°C to 950°C at a rate of 10-15°C / min, and kept warm for 0.5-1 hour, to obtain product 1, and the thickness of the ceramic fiber blanket is 232mm.

[0027] Embodiment 2:

[0028] Add 66 parts of aluminum oxide powder with an average particle size of 1μm to 3μm, 21 parts of silicon oxide powder, and 11 parts of magnesium oxide, mix well, and melt at a high temperature of 1200°C for 2 hours to obtain a solution; add 2 parts of 16wt% polyvinyl pyrrolidone to the solution to adjust the viscosity of the molten solution; add the above solution to a spinning cylinder, heat to 550°C under nitrogen protection, stand for 0.5 hour to degas, then reduce the temperature to 400°C, set the rotation speed of the spinning cylinder to 400r / min, spin into fibers, and obtain fiber b.

[0029] The fibers obtained above are added to the conveyor belt in the cotton collector to convey the fiber filaments to the roller press for rolling, and then the formed fiber blanket is conveyed to the needle punching machine for needle punching to obtain a fiber blanket semi-finished product. The fiber blanket semi-finished product is placed in a TL1200-12001 resistance tube furnace, and the temperature of the first section is set to increase from room temperature to 325°C at a rate of 5-10°C / min under a nitrogen atmosphere, and keep warm for 1 hour; the temperature of the second section is increased from 325°C to 600°C at a rate of 10-15°C / min, and kept warm for 1.5 hours; the temperature of the third section is increased from 600°C to 1000°C at a rate of 10-15°C / min, and kept warm for 1 hour to obtain product 2, and the thickness of the ceramic fiber blanket is 251mm.

[0030] Embodiment three;

[0031] 70 parts of aluminum oxide powder with an average particle size of 1 μm to 3 μm, 20 parts of silicon oxide powder, and 8 parts of magnesium oxide are added and mixed evenly, and then melted at a high temperature of 1200°C for 2 hours to obtain a solution; 2 parts of 16wt% polyvinyl pyrrolidone are added to the solution to adjust the viscosity of the molten solution; the above solution is added to a spinning cylinder, heated to 550°C under nitrogen protection, and allowed to stand for 0.5 hour for degassing, and then the temperature is reduced to 400°C, the rotation speed of the spinning cylinder is set to 400r / min, and the fiber is spun to obtain fiber c.

[0032] The fibers obtained above are added to the conveyor belt in the cotton collector to convey the fiber filaments to the roller press for rolling, and then the formed fiber blanket is conveyed to the needle punching machine for needle punching to obtain a fiber blanket semi-finished product. The fiber blanket semi-finished product is placed in a TL1200-12001 resistance tube furnace, and the temperature of the first section is set to increase from room temperature to 300°C at a rate of 5-10°C / min under a nitrogen atmosphere, and keep warm for 1 hour; the temperature of the second section is increased from 300°C to 600°C at a rate of 10-15°C / min, and kept warm for 1 hour; the temperature of the third section is increased from 600°C to 1000°C at a rate of 10-15°C / min, and kept warm for 1 hour, to obtain product 3, the thickness of the ceramic fiber blanket is 246mm.

[0033] Embodiment 4:

[0034] 66 parts of aluminum oxide powder with an average particle size of 1 μm to 3 μm, 21 parts of silicon oxide powder, and 11 parts of magnesium oxide are added and mixed evenly, and then melted at a high temperature of 1200°C for 2 hours to obtain a solution; 2 parts of 17wt% polyvinyl pyrrolidone are added to the solution to adjust the viscosity of the molten solution; the above solution is added to a spinning cylinder, heated to 550°C under nitrogen protection, and allowed to stand for 0.5 hour for degassing, and then the temperature is reduced to 400°C, the rotation speed of the spinning cylinder is set to 400r / min, and the fiber is spun to obtain fiber d.

[0035] The fibers obtained above are added to the conveyor belt in the cotton collector to convey the fiber filaments to the roller press for rolling, and then the formed fiber blanket is conveyed to the needle punching machine for needle punching to obtain a fiber blanket semi-finished product. The fiber blanket semi-finished product is placed in a TL1200-12001 resistance tube furnace, and the temperature of the first section is set to increase from room temperature to 350°C at a rate of 5-10°C / min under a nitrogen atmosphere, and keep warm for 1.5 hours; the temperature of the second section is increased from 350°C to 700°C at a rate of 10-15°C / min, and kept warm for 2 hours; the temperature of the third section is increased from 700°C to 1050°C at a rate of 10-15°C / min, and kept warm for 1 hour to obtain product 4, and the thickness of the ceramic fiber blanket is 264mm.

[0036] Embodiment five;

[0037] Add 66 parts of aluminum oxide powder with an average particle size of 1μm to 3μm, 21 parts of silicon oxide powder, and 11 parts of magnesium oxide, mix well, and melt at a high temperature of 1200°C for 2 hours to obtain a solution; add 2 parts of 18wt% polyvinyl pyrrolidone to the solution to adjust the viscosity of the molten solution; add the above solution to a spinning cylinder, heat to 550°C under nitrogen protection, stand for 0.5 hour to degas, then reduce the temperature to 400°C, set the rotation speed of the spinning cylinder to 400r / min, spin into fibers, and obtain fiber e.

[0038] The fibers obtained above are added to the conveyor belt in the cotton collector to convey the fiber filaments to the roller press for rolling, and then the formed fiber blanket is conveyed to the needle punching machine for needle punching to obtain a fiber blanket semi-finished product. The fiber blanket semi-finished product is placed in a TL1200-12001 resistance tube furnace, and the temperature of the first section is set to increase from room temperature to 350°C at a rate of 5-10°C / min under a nitrogen atmosphere, and keep warm for 1.5 hours; the temperature of the second section is increased from 350°C to 700°C at a rate of 10-15°C / min, and kept warm for 2 hours; the temperature of the third section is increased from 700°C to 1050°C at a rate of 10-15°C / min, and kept warm for 1 hour, to obtain product 5, the thickness of the ceramic fiber blanket is 258mm.

[0039] Embodiment six;

[0040] 72 parts of aluminum oxide powder with an average particle size of 1 μm to 3 μm, 21 parts of silicon oxide powder, and 5 parts of magnesium oxide are added and mixed evenly, and then melted at a high temperature of 1200°C for 2 hours to obtain a solution; 2 parts of 16wt% polyvinyl pyrrolidone are added to the solution to adjust the viscosity of the molten solution; the above solution is added to a spinning cylinder, heated to 550°C under nitrogen protection, and allowed to stand for 0.5 hour for degassing, and then the temperature is reduced to 400°C, the rotation speed of the spinning cylinder is set to 400r / min, and the fiber is spun to obtain fiber f.

[0041] The fibers obtained above are added to the conveyor belt in the cotton collector to convey the fiber filaments to the roller press for rolling, and then the formed fiber blanket is conveyed to the needle punching machine for needle punching to obtain a fiber blanket semi-finished product. The fiber blanket semi-finished product is placed in a TL1200-12001 resistance tube furnace, and the temperature of the first section is set to increase from room temperature to 350°C at a rate of 5-10°C / min under a nitrogen atmosphere, and keep warm for 1.5 hours; the temperature of the second section is increased from 350°C to 600°C at a rate of 10-15°C / min, and kept warm for 2 hours; the temperature of the third section is increased from 600°C to 1000°C at a rate of 10-15°C / min, and kept warm for 1 hour, to obtain product 6, the thickness of the ceramic fiber blanket is 263mm.

[0042] Comparative Example 1;

[0043] Comparative Example 1 is the control group of fiber a in Example 1, in which 15 wt % of polyvinyl pyrrolidone in Example 1 is replaced by polyvinyl alcohol, and the other raw materials, raw material amounts and preparation methods remain unchanged, and finally fiber g is obtained.

[0044] Comparative Example 2:

[0045] Comparative Example 2 is the control group of Product 1 in Example 1. The high-temperature heat treatment in Example 1 adopts a one-stage heating method: the temperature of the first stage is set from room temperature to 1000°C at a rate of 5-10°C / min under a nitrogen atmosphere, and the temperature is kept for 1 hour to obtain Product 7.

[0046] Test example 1:

[0047] Fiber mechanical properties test

[0048] The present invention refers to the method disclosed in the prior art, and uses a single-filament strength meter to test the room temperature tensile strength of the above-mentioned fibers a to f, heats to 300°C, sticks the ceramic fiber to a coordinate paper with a span of 25 mm, and fixes it on the strength meter. Cut the paper frame, the tensile rate is 2 mm / min, the maximum tensile load is measured, and the diameter of the fiber is measured with an optical microscope. Each fiber test sample is 20, and the average value is taken as the strength result. The results are shown in Table 1.

[0049] The fiber was placed in a tubular furnace, vacuumed and replaced with high-purity argon three times, heated to 1200°C for 1 hour, cooled to room temperature, and the fiber single-filament strength was measured with a single-filament strength meter. The number of samples was 20, and the average value was taken. The results are shown in Table 1.

[0050] Table 1

[0051]

[0052]

[0053] From the above table, we can see that the strength of the fiber decreases with the increase of temperature. The single fiber strength of the fiber reaches 2.35GPa. After treatment at 1200℃, the structure of the fiber remains dense and the strength of the fiber is 1.55GPa. Comprehensive analysis shows that with the increase of the concentration of polyvinyl pyrrolidone, the strength of the fiber gradually increases, and the strength is the highest when the concentration of polyvinyl pyrrolidone is 17wt%.

[0054] Test Example 2:

[0055] Ceramic blanket performance test

[0056] According to the test method of GB / T 17911, the tensile strength test and high temperature resistance test were carried out on products 1 to 7. The test results are shown in Table 2

[0057] Table 2

[0058] Serial number Tensile strength(GPa) Temperature resistance(℃) Product 1 19 1300 Product 2 20 1320 Product 3 21 1400 Product 4 23 1450 Product 5 23 1400 Product 6 22 1420 Product 7 12 1200

[0059] From the above table, we can see that the tensile strength of ceramic fiber blanket is improved compared with monofilament, and the change rule is consistent with that of monofilament. The temperature resistance is between 1300 and 1450℃.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for preparing a novel ceramic fiber blanket, characterized in that: The following steps are involved: Step a: adding aluminum oxide powder, silicon oxide powder and magnesium oxide in proportions, mixing evenly, and heating at high temperature to obtain a solution; Step b: adding a binder to the melt to adjust the viscosity of the molten solution; Step c: adding the above solution into a spinning cylinder, heating it under nitrogen protection, cooling it down after standing, and spinning it into fibers; Step d: adding the prepared fibers into a forming machine to obtain a semi-finished fiber blanket; Step e: placing the fiber blanket semi-finished product into a TL1200-12001 resistance tube furnace and performing high temperature heat treatment in a nitrogen atmosphere according to a certain procedure; The proportions are 65-75 parts of aluminum oxide powder, 20-25 parts of silicon oxide powder, 5-15 parts of magnesium oxide, and 1-4 parts of binder.

2. The method for preparing a novel ceramic fiber blanket according to claim 1, characterized in that: The average particle size of the aluminum oxide and silicon oxide powders is 1 μm to 3 μm.

3. The method for preparing a novel ceramic fiber blanket according to claim 1, characterized in that: In the step a, the high temperature melting temperature is 1200° C. and the melting time is 1 to 2 hours. The method for preparing a novel ceramic fiber blanket according to claim 1 is characterized in that the binder is 15-18wt% polyvinyl pyrrolidone.

4. The method for preparing a novel ceramic fiber blanket according to claim 1, characterized in that: The operation of step c is: adding the solution of step b above into the spinning cylinder, heating to 550°C under nitrogen protection, standing for 0.5 hours for degassing, then lowering the temperature to 400°C, setting the rotation speed of the spinning cylinder to 400r / min, and spinning into fibers.

5. The method for preparing a novel ceramic fiber blanket according to claim 1, characterized in that: The forming in step d is as follows: adding the fibers obtained in step c to a cotton collector and conveying the fiber filaments to a roller press for rolling, and then conveying the formed fiber blanket to a needle punching machine for needle punching to obtain a semi-finished fiber blanket.

6. The method for preparing a novel ceramic fiber blanket according to claim 1, characterized in that: The procedure of high temperature heat treatment in step e is as follows: in a nitrogen atmosphere, the temperature of the first section is set to rise from room temperature to 300-350°C at a rate of 5-10°C / min, and kept warm for 1-1.5 hours; the temperature of the second section is set to rise from 300-350°C to 550-700°C at a rate of 10-15°C / min, and kept warm for 1-2 hours; the temperature of the third section is set to rise from 550-700°C to 950-1050°C at a rate of 10-15°C / min, and kept warm for 0.5-1 hour.

7. The method for preparing a novel ceramic fiber blanket according to claim 1, characterized in that: The thickness of the formed fiber blanket is 200-300 mm.

8. A new type of ceramic fiber blanket, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 7.

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