Lightweight aluminum phosphate porous ceramic with sound absorption performance as well as preparation method and application of lightweight aluminum phosphate porous ceramic

Abstract

The invention relates to the technical field of ceramic materials, and discloses a lightweight aluminum phosphate porous ceramic with sound absorption performance and a preparation method and application thereof, the preparation method comprises the following steps: dispersing aluminum phosphate powder and a gel in deionized water, and uniformly dispersing to obtain aluminum phosphate ceramic slurry; adding a foaming agent into the aluminum phosphate ceramic slurry to obtain to-be-foamed slurry; stirring the slurry to be foamed until the slurry is foamed to obtain foamed slurry, injecting the foamed slurry into a mold, and curing, demolding and drying to obtain an aluminum phosphate porous ceramic green body; and sintering the aluminum phosphate porous ceramic green body to obtain the light aluminum phosphate porous ceramic with sound absorption performance. The preparation method provided by the invention is simple in process, can realize spontaneous solidification at room temperature, accelerates drying and solidification, saves time and cost, does not introduce impurities, is non-toxic, harmless and environment-friendly, and can be used for preparing the aluminum phosphate porous ceramic with high porosity; the porosity of the porous ceramic can be regulated and controlled by changing the stirring time.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, in particular to a lightweight porous aluminum phosphate ceramic with sound absorption performance, a preparation method and an application thereof. Background Art

[0002] Porous ceramic materials offer excellent properties such as light weight, low thermal conductivity, good mechanical properties, high temperature resistance, and acid and alkali resistance. They are used in thermal insulation, flue gas filtration, catalytic supports, and noise reduction. Therefore, the preparation of porous ceramics with high porosity, high strength, and stable performance is crucial for their application in various fields.

[0003] The main methods for preparing porous ceramics include adding pore-forming agents, foaming, templates and gel casting. The adding pore-forming agent method utilizes the decomposition of the pore-forming agent to form pores in the ceramic body. This method is simple in process and low in cost. The prepared porous ceramics have a high porosity, but the pore distribution is uneven, resulting in low mechanical properties. Therefore, how to improve the mechanical properties of porous ceramics under the condition of high porosity is one of the key issues in preparing porous ceramics with stable performance. The gel casting method is to add an appropriate amount of polymer monomers to the slurry, and promote the monomers to undergo polymerization reaction to form a three-dimensional gel network structure through chemical induction or thermal induction, so that the powder is evenly and stably dispersed in the slurry. Finally, ceramics with uniform composition structure and high strength are obtained through injection molding, curing, drying and sintering. Therefore, the use of gel casting to prepare porous ceramics can ensure that the products have good mechanical properties. However, most of the polymer monomers used in traditional gel casting systems have certain toxicity and will inevitably cause harm to the human body and the environment. Although the strength of porous ceramics prepared by gel injection molding is improved compared with other methods, its compressive strength and porosity still cannot meet the requirements for use in noise reduction, sound absorption, and thermal insulation.

[0004] Therefore, there is an urgent need for lightweight aluminum phosphate porous ceramics with sound absorption properties and their preparation methods and applications to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems in the prior art of porous ceramic materials such as high porosity but low strength. By selecting isobutylene-maleic anhydride copolymer as a gelling agent and dispersant, a gel injection molding process combined with a foaming method is adopted to prepare porous ceramics, thereby obtaining aluminum phosphate porous ceramics with good slurry stability, high porosity, and excellent mechanical and acoustic properties.

[0006] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0007] A method for preparing a lightweight porous aluminum phosphate ceramic with sound absorption performance comprises the following steps:

[0008] S1, dispersing aluminum phosphate powder and a gelling agent in deionized water to obtain aluminum phosphate ceramic slurry after uniform dispersion;

[0009] S2, adding a foaming agent to an aluminum phosphate ceramic slurry to obtain a slurry to be foamed; stirring the slurry to be foamed until foamed to obtain a foamed slurry, injecting the foamed slurry into a mold, and obtaining an aluminum phosphate porous ceramic body after curing, demolding and drying;

[0010] S3, sintering the porous aluminum phosphate ceramic body to obtain a lightweight porous aluminum phosphate ceramic with sound absorption performance.

[0011] Preferably, in step S1, the gelling agent is isobutylene-maleic anhydride copolymer; the amount of the gelling agent used is 0.4-1.0 wt.% of the mass of the aluminum phosphate powder.

[0012] Specifically, the molecular weight of the isobutylene-maleic anhydride copolymer is 55,000-65,000.

[0013] Specifically, step S1 includes the following steps:

[0014] S1. Weigh aluminum phosphate powder and a gelling agent respectively, disperse them in deionized water, and obtain a uniformly dispersed aluminum phosphate ceramic slurry by mechanical stirring for 1-3 hours. The gelling agent is an isobutylene-maleic anhydride copolymer. The amount of the gelling agent used is 0.4-1.0 wt.% of the mass of the aluminum phosphate powder.

[0015] Preferably, in step S2, the foaming agent is propyl gallate, and the amount of the foaming agent used does not exceed 4 wt.% of the mass of the aluminum phosphate powder;

[0016] The solid content of the slurry to be foamed is 40 vol.%.

[0017] Specifically, the calculation formula for the solid content of the slurry to be foamed in the present invention is:

[0018] Solid content of the slurry to be foamed (vol.%) = [mass of aluminum phosphate powder (g) ÷ density of aluminum phosphate powder (g·cm -3 )]÷{[Mass of aluminum phosphate powder (g)÷density of aluminum phosphate powder (g·cm -3 )] + [mass of gelling agent (g) ÷ density of gelling agent (g·cm -3 )] + [mass of foaming agent (g) ÷ density of foaming agent (g·cm -3 ) + [mass of deionized water (g) ÷ density of deionized water (g·cm -3 )]}.

[0019] Preferably, in step S2, the viscosity of the slurry after foaming is 1-10 Pa·s.

[0020] The viscosity of the foamed slurry is 1-10Pa·s, which is more suitable for injection molding. Too thick or too thin will lead to incomplete green body during demoulding. When the viscosity of the foamed slurry is greater than 10Pa·s, it will cause poor demoulding effect or low porosity. The viscosity here is the viscosity of the slurry measured by DV-1 digital viscometer in 1s -1 viscosity.

[0021] Preferably, in step S2, the curing temperature of the curing process is 25° C., and the curing time is 5-10 hours.

[0022] Preferably, in step S2, the drying temperature of the drying process is 40-50° C., and the drying time is 24-48 hours.

[0023] Specifically, step S2 includes the following steps:

[0024] S2, weighing no more than 4wt.% of propyl gallate as a foaming agent based on the mass of aluminum phosphate powder and adding it to the aluminum phosphate ceramic slurry to obtain a slurry to be foamed; stirring the slurry to be foamed for 1-5h until foaming to obtain a foamed slurry, injecting the foamed slurry into a mold, and obtaining an aluminum phosphate porous ceramic body after curing, demolding and drying; the curing temperature is 25°C and the time is 5-10h; the drying temperature is 40-50°C and the time is 24-48h.

[0025] Preferably, in step S3, the sintering process is performed under the following conditions: pressureless sintering in an air atmosphere.

[0026] Preferably, in step S3, the temperature curve of the sintering process is: first heating to 200-400°C at a rate of 1-2°C / min and keeping warm for 1-3h; then heating to 1100-1200°C at a rate of 2-5°C / min and keeping warm for 1-3h; after the holding stage, cooling to 700°C at a rate of 2°C / min, and then cooling to room temperature with the furnace.

[0027] Specifically, step S3 includes the following steps:

[0028] S3, pressurelessly sintering the obtained porous aluminum phosphate ceramic body in an air atmosphere to obtain the porous aluminum phosphate ceramic. The temperature rise regime for the pressureless sintering includes: first heating to 200-400°C at a rate of 1-2°C / min and holding at that temperature for 1-3 hours. During this stage, the temperature is slowly increased to prevent cracking of the porous aluminum phosphate ceramic body and to fully decompose the added organic matter; then heating to 1100-1200°C at a rate of 2-5°C / min and holding at that temperature for 1-3 hours; after the holding stage, cooling to 700°C at a rate of 2°C / min, and then cooling to room temperature in the furnace.

[0029] Preferably, the light aluminum phosphate porous ceramic with sound absorption performance has a porosity of 55.2-82.5%, a compressive strength of 1.23-3.8 MPa, and a sound absorption coefficient of 0.22-0.66.

[0030] Further preferably, the porosity of the porous aluminum phosphate ceramic can reach up to 82.5%, the compressive strength can reach 1.23 MPa, and the sound absorption coefficient can reach 0.66, which has excellent sound absorption performance.

[0031] The present invention also includes a light aluminum phosphate porous ceramic with sound absorption performance prepared by the above preparation method.

[0032] The present invention also includes the application of lightweight aluminum phosphate porous ceramics with sound absorption performance in the fields of noise reduction, sound absorption, and heat insulation.

[0033] The volume density of the light aluminum phosphate porous ceramic with sound absorption performance of the present invention is 0.4-1.1g·cm -3 .

[0034] Working principle:

[0035] The present invention uses an isobutylene-maleic anhydride copolymer as a gelling agent, which also acts as a dispersant. The isobutylene-maleic anhydride copolymer primarily forms hydrogen bonds through the interaction between functional groups on the molecular chain and groups on the powder surface, achieving gel curing. This copolymer is low-cost, spontaneously solidifies, and is non-toxic and harmless. It effectively addresses the high levels of organic solvents and monomers added and the significant hazards associated with traditional gel casting systems.

[0036] By adding a small amount of isobutylene-maleic anhydride copolymer, a stable aluminum phosphate ceramic slurry was obtained, and the preparation of aluminum phosphate porous ceramics with high porosity, high compressive strength and excellent sound absorption performance was achieved.

[0037] Aluminum phosphate ceramics have excellent thermal stability and wave transmission properties, and have great application potential in high-temperature wave transmission, catalysis, and sound absorption. Therefore, aluminum phosphate was selected as the material, and isobutylene-maleic anhydride copolymer was used as a dispersant and gelling agent. Combined with gel casting and foaming methods, a porous ceramic with high porosity, high strength, and excellent sound absorption properties was prepared. This broadens the application of aluminum phosphate materials in the fields of thermal insulation, wave transmission, noise reduction, and sound insulation.

[0038] Beneficial effects:

[0039] (1) The present invention uses isobutylene-maleic anhydride copolymer as a gelling agent and dispersant. The groups on its molecular chain can interact with the charges and groups on the surface of the aluminum phosphate powder to form an elastic three-dimensional gel network, so that the powder is evenly dispersed and in-situ solidified and formed, thereby improving the mechanical properties of the high-porosity aluminum phosphate porous ceramic; at the same time, it can achieve spontaneous solidification at room temperature, accelerate drying and solidification, save time and cost, and will not introduce impurities, is non-toxic and harmless, and is environmentally friendly;

[0040] (2) The present invention uses propyl gallate as a foaming agent, which can reduce the surface tension of the liquid, making it easier for the air introduced by stirring to form bubbles in the slurry, thereby improving the foaming property of the slurry; at the same time, a solid film is formed at the gas-liquid interface, which plays a role in stabilizing the foam in the slurry; the use of propyl gallate adjusts the hydrophobic state of the surface of the aluminum phosphate particles and makes the pores uniformly distributed, which is beneficial to improving the compressive strength of the aluminum phosphate porous ceramics;

[0041] (3) The preparation method provided by the present invention has a simple process and can prepare aluminum phosphate porous ceramics with high porosity. At the same time, the porosity of the porous ceramics can be controlled by changing the stirring time (the stirring time after adding the foaming agent in step S2) to achieve a maximum porosity of more than 80%, while ensuring high compressive strength and excellent acoustic performance, and is widely used in the fields of noise reduction, sound absorption, and heat insulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 XRD patterns of the porous aluminum phosphate ceramics prepared in Example 3 and Comparative Example 1;

[0043] Figure 2 These are SEM images of the porous aluminum phosphate ceramics prepared in Examples 1-3; (a) corresponds to the porous aluminum phosphate ceramic prepared in Example 1, (b) corresponds to the porous aluminum phosphate ceramic prepared in Example 2, (c) corresponds to the porous aluminum phosphate ceramic prepared in Example 3, and (d) is an enlarged view of the yellow dotted area in (c);

[0044] Figure 3 The sound absorption coefficient curves of the porous aluminum phosphate ceramics prepared in Examples 1-5 and Comparative Example 1 are shown. DETAILED DESCRIPTION

[0045] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0046] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses industrial purity or conventional purity used in the art.

[0047] The devices used in the present invention are not particularly limited and can be devices commonly used in the art.

[0048] In the following comparative examples and embodiments:

[0049] The isobutylene-maleic anhydride copolymer used is: Isobam-104, with a molecular weight of 55,000-65,000; an LC-OES-60SH electric stirrer is used for stirring;

[0050] In the following examples and comparative examples, the density of aluminum phosphate powder (AlPO4) is 2.304 g·cm -3 The density of gel Isobam-104 is 1.3 g·cm -3 The density of the foaming agent propyl gallate (PG) is 1.4 g·cm -3 .

[0051] Specific implementation methods are shown in the following examples:

[0052] Example 1

[0053] A method for preparing a lightweight porous aluminum phosphate ceramic with sound absorption performance comprises the following steps:

[0054] (1) 75 g of aluminum phosphate powder and 0.75 g of gelling agent (isobutylene-maleic anhydride copolymer) were weighed and dispersed in 46.11 g of deionized water. A uniformly dispersed aluminum phosphate ceramic slurry was obtained by mechanical stirring for 1 h (rotation speed of 500 rpm);

[0055] (2) Weighing 3 g of a foaming agent (propyl gallate) and adding it to the above-mentioned aluminum phosphate ceramic slurry to obtain a slurry to be foamed with a solid content of 40 vol.%; the slurry to be foamed was further stirred for 1 hour for foaming treatment to obtain a foamed slurry, and the volume expansion of the foamed slurry was measured to be 1.5 times the original volume, that is, the volume expansion ratio was 1.5, and the foamed slurry was injected into a mold, cured at room temperature (25°C) for 5 hours, dried at 50°C for 24 hours, and then demolded to obtain an aluminum phosphate porous ceramic body;

[0056] (3) The obtained porous aluminum phosphate ceramic body was pressurelessly sintered in an air atmosphere, first heated to 400°C at a rate of 1°C / min and kept warm for 3 hours, then heated to 1150°C at a rate of 2°C / min and kept warm for 1 hour; then cooled to 700°C at a rate of 2°C / min, and then cooled to room temperature in the furnace to finally obtain porous aluminum phosphate ceramics.

[0057] Example 2

[0058] A method for preparing a lightweight porous aluminum phosphate ceramic with sound absorption performance comprises the following steps:

[0059] (1) 75 g of aluminum phosphate powder and 0.75 g of gelling agent (isobutylene-maleic anhydride copolymer) were weighed and dispersed in 46.11 g of deionized water. A uniformly dispersed aluminum phosphate ceramic slurry was obtained by mechanical stirring for 1 h (rotation speed of 500 rpm);

[0060] (2) Weighing 3 g of a foaming agent (propyl gallate) and adding it to the above-mentioned aluminum phosphate ceramic slurry to obtain a slurry to be foamed with a solid content of 40 vol.%; continuing to stir the slurry to be foamed for 2 h to obtain a foamed slurry, and measuring that the volume expansion of the foamed slurry is twice that of the original volume, that is, the volume expansion ratio is 2; injecting the foamed slurry into a mold, curing at room temperature (25°C) for 5 h, drying at 50°C for 24 h, and then demolding to obtain an aluminum phosphate porous ceramic body;

[0061] (3) The obtained porous aluminum phosphate ceramic body was pressurelessly sintered in an air atmosphere, first heated to 400°C at a rate of 1°C / min and kept warm for 3 hours, then heated to 1150°C at a rate of 2°C / min and kept warm for 1 hour; then cooled to 700°C at a rate of 2°C / min, and then cooled to room temperature in the furnace to finally obtain porous aluminum phosphate ceramics.

[0062] Example 3

[0063] A method for preparing a lightweight porous aluminum phosphate ceramic with sound absorption performance comprises the following steps:

[0064] (1) 75 g of aluminum phosphate powder and 0.75 g of gelling agent (isobutylene-maleic anhydride copolymer) were weighed and dispersed in 46.11 g of deionized water. A uniformly dispersed aluminum phosphate ceramic slurry was obtained by mechanical stirring for 1 h (rotation speed of 500 rpm);

[0065] (2) Weighing 3 g of a foaming agent (propyl gallate) and adding it to the above-mentioned aluminum phosphate ceramic slurry to obtain a slurry to be foamed with a solid content of 40 vol.%; the slurry to be foamed was further stirred for 3 h for foaming treatment to obtain a foamed slurry, and the volume expansion of the foamed slurry was measured to be 3 times the original volume, that is, the volume expansion ratio was 3; the foamed slurry was injected into a mold, cured at room temperature (25°C) for 5 h, dried at 50°C for 24 h, and then demolded to obtain an aluminum phosphate porous ceramic body;

[0066] (3) The obtained porous aluminum phosphate ceramic body was pressurelessly sintered in an air atmosphere, first heated to 400°C at a rate of 1°C / min and kept warm for 3 hours, then heated to 1150°C at a rate of 2°C / min and kept warm for 1 hour; then cooled to 700°C at a rate of 2°C / min, and then cooled to room temperature in the furnace to finally obtain porous aluminum phosphate ceramics.

[0067] Example 4

[0068] A method for preparing a lightweight porous aluminum phosphate ceramic with sound absorption performance comprises the following steps:

[0069] (1) 75 g of aluminum phosphate powder and 0.53 g of gelling agent (isobutylene-maleic anhydride copolymer) were weighed and dispersed in 46.28 g of deionized water. A uniformly dispersed aluminum phosphate ceramic slurry was obtained by mechanical stirring for 1 h (rotation speed of 500 rpm);

[0070] (2) Weighing 3 g of a foaming agent (propyl gallate) and adding it to the above-mentioned aluminum phosphate ceramic slurry to obtain a slurry to be foamed with a solid content of 40 vol.%; continuing to stir the slurry to be foamed for 3 h to obtain a foamed slurry, injecting the foamed slurry into a mold, curing it at room temperature (25° C.) for 5 h, drying it at 50° C. for 24 h, and then demolding it to obtain an aluminum phosphate porous ceramic body;

[0071] (3) The obtained porous aluminum phosphate ceramic body was pressurelessly sintered in an air atmosphere, first heated to 400°C at a rate of 1°C / min and kept warm for 3 hours, then heated to 1150°C at a rate of 2°C / min and kept warm for 1 hour; then cooled to 700°C at a rate of 2°C / min, and then cooled to room temperature in the furnace to finally obtain porous aluminum phosphate ceramics.

[0072] Example 5

[0073] A method for preparing a lightweight porous aluminum phosphate ceramic with sound absorption performance comprises the following steps:

[0074] (1) 75 g of aluminum phosphate powder and 0.3 g of gelling agent (isobutylene-maleic anhydride copolymer) were weighed and dispersed in 46.45 g of deionized water. After mechanical stirring for 1 h (rotation speed of 500 rpm), a uniformly dispersed aluminum phosphate ceramic slurry was obtained;

[0075] (2) Weighing 3 g of a foaming agent (propyl gallate) and adding it to the above-mentioned aluminum phosphate ceramic slurry to obtain a slurry to be foamed with a solid content of 40 vol.%; continuing to stir the slurry to be foamed for 3 h to obtain a foamed slurry, injecting the foamed slurry into a mold, curing it at room temperature for 5 h, drying it at 50° C. for 24 h, and then demolding it to obtain an aluminum phosphate porous ceramic body;

[0076] (3) The obtained porous aluminum phosphate ceramic body was pressurelessly sintered in an air atmosphere, first heated to 400°C at a rate of 1°C / min and kept warm for 3 hours, then heated to 1150°C at a rate of 2°C / min and kept warm for 1 hour; then cooled to 700°C at a rate of 2°C / min, and then cooled to room temperature in the furnace to finally obtain porous aluminum phosphate ceramics.

[0077] Comparative Example 1

[0078] The preparation method of porous aluminum phosphate ceramics comprises the following steps:

[0079] (1) 75 g of aluminum phosphate powder and 0.75 g of gelling agent (isobutylene-maleic anhydride copolymer) were weighed and dispersed in 48.25 g of deionized water. A uniformly dispersed aluminum phosphate ceramic slurry was obtained by mechanical stirring for 3 h (rotation speed was 500 rpm);

[0080] (2) injecting the aluminum phosphate ceramic slurry obtained above into a mold, curing at room temperature (25° C.) for 5 h, drying at 50° C. for 24 h, and then demolding to obtain an aluminum phosphate ceramic body;

[0081] (3) The obtained aluminum phosphate ceramic body was pressurelessly sintered in an air atmosphere, first heated to 400°C at a rate of 1°C / min and kept warm for 3 hours, then heated to 1150°C at a rate of 2°C / min and kept warm for 1 hour; then cooled to 700°C at a rate of 2°C / min, and then cooled to room temperature in the furnace to finally obtain aluminum phosphate porous ceramics.

[0082] Table 1 shows the performance parameters of the porous aluminum phosphate ceramics prepared in Examples 1-5 and Comparative Example 1. The viscosity data is obtained by measuring the viscosity of the slurry in 1s using a DV-1 digital viscometer. -1 The viscosity of the slurry after foaming in step (2) was measured in Examples 1 to 5, and the viscosity of the aluminum phosphate ceramic slurry obtained in step (1) was measured in Comparative Example 1. The bulk density, porosity, compressive strength, and sound absorption coefficient measured are all related data of the prepared aluminum phosphate porous ceramics. The porosity is calculated by the formula: (1-bulk density / theoretical density) × 100%, where the theoretical density of aluminum phosphate is 2.304 g·cm -3 The sound absorption coefficient is the sound absorption coefficient of the porous aluminum phosphate ceramic sample measured by SW4601 acoustic impedance tube in the frequency range of 800Hz-6300Hz.

[0083] Table 1 Performance parameters of porous aluminum phosphate ceramics prepared in Examples 1-5 and Comparative Example 1

[0084]

[0085]

[0086] The aluminum phosphate porous ceramics prepared in Example 3 and Comparative Example 1 were characterized by X-ray diffraction (XRD). Figure 1 As shown, Figure 1 The curve represented by "4 wt. %" is the porous aluminum phosphate ceramic prepared in Example 3, and the curve represented by "0 wt. %" is the porous aluminum phosphate ceramic prepared in Comparative Example 1. Figure 1 It can be seen that the porous aluminum phosphate ceramics prepared by the method provided by the present invention are a single phase, indicating that the addition of the gelling agent (isobutylene-maleic anhydride copolymer) and the foaming agent (propyl gallate) will not introduce impurities.

[0087] The morphologies of the porous aluminum phosphate ceramics prepared in Examples 1-3 were tested using scanning electron microscopy (SEM). Figure 2 As shown. Figure 2 It can be seen that the porosity of the porous aluminum phosphate ceramics prepared by the method provided by the present invention is relatively high, and the porosity and pore structure of the porous aluminum phosphate ceramics can be regulated by adjusting the stirring time. When the stirring time reaches 3h, the shape of the pores inside the porous ceramics is close to circular and the pore size distribution is relatively uniform. As can be seen from Table 1, when the porosity of the porous ceramics reaches 82.5%, it can still maintain a strength of 1.23MPa. This is because the groups on the molecular chain of the gelling agent (isobutylene-maleic anhydride copolymer) and the charges and groups on the surface of the aluminum phosphate powder interact to form an elastic three-dimensional gel network, which makes the powder more evenly dispersed and in-situ solidified and formed, thereby making the compressive strength of the porous aluminum phosphate ceramics higher.

[0088] From the viscosity data and porosity data of Comparative Example 1 in Table 1, it can be seen that when the viscosity of the slurry is greater than 10 Pa·s, the porosity will be low.

[0089] like Figure 3 The following are the sound absorption coefficient curves of the porous aluminum phosphate ceramics prepared in Examples 1-5 and Comparative Example 1. Figure 3 As can be seen from Table 1, the amount of gelling agent used in Examples 3 to 5 changes; when comparing Example 3 with Comparative Example 1, Comparative Example 1 does not use a foaming agent; it can be understood that the more the amount of gelling agent (isobutylene-maleic anhydride copolymer) and foaming agent (propyl gallate) added, the lower the viscosity of the slurry, the greater the degree of foaming, thereby increasing the porosity of the porous aluminum phosphate ceramic and further improving the sound absorption coefficient, up to 0.66, showing excellent sound absorption performance. This shows that the addition of the gelling agent and foaming agent improves the hydrophobicity of the particles and improves the stability of the foam in the slurry, ultimately making the prepared porous aluminum phosphate ceramic have the characteristics of high porosity, high compressive strength and excellent sound absorption performance.

[0090] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Any technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a lightweight porous aluminum phosphate ceramic with sound absorption performance, characterized in that: The following steps are involved: S1, dispersing aluminum phosphate powder and a gelling agent in deionized water to obtain aluminum phosphate ceramic slurry after uniform dispersion; S2, adding a foaming agent to an aluminum phosphate ceramic slurry to obtain a slurry to be foamed; stirring the slurry to be foamed until foamed to obtain a foamed slurry, injecting the foamed slurry into a mold, and obtaining an aluminum phosphate porous ceramic body after curing, demolding and drying; S3, sintering the porous aluminum phosphate ceramic body to obtain a lightweight porous aluminum phosphate ceramic with sound absorption performance.

2. The method for preparing the light aluminum phosphate porous ceramic with sound absorption performance according to claim 1, characterized in that: In the step S1, the gelling agent is isobutylene-maleic anhydride copolymer; the amount of the gelling agent used is 0.4-1.0 wt.% of the mass of the aluminum phosphate powder.

3. The method for preparing the light aluminum phosphate porous ceramic with sound absorption performance according to claim 1, characterized in that: In step S2, the foaming agent is propyl gallate, and the amount of the foaming agent used does not exceed 4 wt.% of the mass of the aluminum phosphate powder; The solid content of the slurry to be foamed is 40 vol.%.

4. The method for preparing the light aluminum phosphate porous ceramic with sound absorption performance according to claim 1, characterized in that: In the step S2, the viscosity of the slurry after foaming is 1-10 Pa·s.

5. The method for preparing the light aluminum phosphate porous ceramic with sound absorption performance according to claim 1, characterized in that: In the step S2, the curing temperature of the curing process is 25° C. and the curing time is 5-10 hours.

6. The method for preparing the light aluminum phosphate porous ceramic with sound absorption performance according to claim 1, characterized in that: In step S2, the drying temperature of the drying process is 40-50° C., and the drying time is 24-48 hours.

7. The method for preparing the light aluminum phosphate porous ceramic with sound absorption performance according to claim 1, characterized in that: In step S3, the sintering process conditions are: pressureless sintering in an air atmosphere; the temperature curve of the sintering process is: first heating to 200-400°C at a rate of 1-2°C / min and keeping warm for 1-3 hours; then heating to 1100-1200°C at a rate of 2-5°C / min and keeping warm for 1-3 hours; after the holding stage, cooling to 700°C at a rate of 2°C / min, and then cooling to room temperature with the furnace.

8. The method for preparing the light aluminum phosphate porous ceramic with sound absorption performance according to claim 1, characterized in that: The light aluminum phosphate porous ceramic with sound absorption performance has a porosity of 55.2-82.5%, a compression strength of 1.23-3.8 MPa, and a sound absorption coefficient of 0.22-0.

66.

9. Lightweight aluminum phosphate porous ceramic with sound absorption performance prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the lightweight aluminum phosphate porous ceramic with sound absorption performance according to claim 9 in the fields of noise reduction, sound absorption, and heat insulation.

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