An ultrasonic sound-absorbing material and its preparation method

Abstract

An ultrasonic sound-absorbing material and its preparation method are disclosed, belonging to the field of sound absorption technology. The raw materials forming the ultrasonic sound-absorbing material, by weight, include 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder, and 6.5-8.5 parts of two-component room-temperature vulcanizing silicone rubber. The above-mentioned ultrasonic sound-absorbing material exhibits excellent absorption capacity for mega-level ultrasound in water, which can meet the requirements for constructing a free sound field for ultrasonic transducer testing. Furthermore, the preparation method of the ultrasonic sound-absorbing material is simple, requiring no large or complex equipment and resulting in low preparation cost.

Description

Technical Field

[0001] This application relates to the field of sound absorption technology, and more specifically, to an ultrasonic sound-absorbing material and its preparation method. Background Technology

[0002] During the commissioning of the transducer sound field in an ultrasonic scanning device, the reflected waves generated by the ultrasonic waves from the four walls of the test pool often interfere with the measurement results, or even make the test impossible. Therefore, it is usually necessary to use sound-absorbing materials to reduce or even eliminate surface reflections.

[0003] Currently, sound-absorbing materials are mainly divided into two categories. One type is used in buildings such as concert halls or cinemas. The main raw material for this type of sound-absorbing material is wood, which absorbs audible sound in the frequency range of 20 to 20,000 Hz. The other type is used in underwater ultrasound, such as submarine sonar, where the highest frequency is usually below 50 kHz. However, the aforementioned sound-absorbing materials are not suitable for the mega-scale (MHz) ultrasonic frequency band used in diagnostic ultrasound.

[0004] With the continuous advancement of the localization of diagnostic ultrasound instruments, the demand for sound field debugging of self-developed transducers in China will become increasingly urgent. There is a pressing need for a sound-absorbing material that is simple to manufacture and has good absorption capabilities for mega-level ultrasonic frequencies in water. Summary of the Invention

[0005] In view of the above-mentioned shortcomings, this application provides an ultrasonic sound-absorbing material and its preparation method to partially or completely improve the absorption problem of mega-frequency ultrasonic waves in related technologies.

[0006] This application is implemented as follows:

[0007] In a first aspect, an example of this application provides an ultrasonic sound-absorbing material, wherein the raw materials forming the ultrasonic sound-absorbing material, by weight, include: 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder, and 6.5-8.5 parts of two-component room temperature vulcanizing silicone rubber.

[0008] In the above process, a sound-absorbing material is formed using 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder, and 6.5-8.5 parts of two-component room-temperature vulcanizing silicone rubber. The mixture of expanded resin microspheres and vulcanizing silicone rubber significantly improves sound attenuation. Tungsten powder increases acoustic impedance, while expanded resin microspheres decrease it. By adjusting the ratio of these two components, the acoustic impedance is made close to that of water, enabling excellent absorption of mega-level ultrasound in water and fulfilling the requirements for constructing a free sound field. According to industry consensus, the sound absorption coefficient of a sound-absorbing material should reach over 99%, corresponding to an echo reduction of 20 dB.

[0009] In conjunction with the first aspect, in an optional embodiment of this application, the particle size of the expanded resin microspheres is 20-50 μm.

[0010] In the above process, expanded resin microspheres with a particle size of 20-50 μm can be combined with 6.5-8.5 parts of two-component room temperature vulcanizing silicone rubber to improve the sound attenuation coefficient.

[0011] In conjunction with the first aspect, in an optional embodiment of this application, the particle size of the tungsten powder is 3-7 μm.

[0012] In conjunction with the first aspect, in optional embodiments of this application, the two-component room temperature vulcanizing silicone rubber includes a main agent and a curing agent. The main agent includes a hydroxyl-terminated polysiloxane. The curing agent includes a catalyst and a crosslinking agent. The catalyst is an organobismuth, organotitanium, or organotin composite catalyst. The crosslinking agent is one or a mixture of tetraethyl orthosilicate, propyl orthosilicate, polyethyl orthosilicate, and polymethyltriethoxysilane.

[0013] In the above-mentioned process, in the raw materials forming the ultrasonic sound-absorbing material, relative to 0.05-0.15 parts of expanded resin microspheres, the addition of 6.5-8.5 parts of 3-7μm tungsten powder can improve the impedance of the ultrasonic sound-absorbing material, making it close to the acoustic impedance of water. This allows it to have good absorption capacity for mega-level ultrasound in water, which can meet the requirements for constructing a free sound field.

[0014] In conjunction with the first aspect, in optional embodiments of this application, the ultrasonic sound-absorbing material is a sawtooth corrugated structure or a flat wedge channel structure.

[0015] In conjunction with the first aspect, in an optional embodiment of this application, the thickness of the ultrasonic sound-absorbing material is 3-5 mm.

[0016] In the above process, ultrasonic sound-absorbing material with a thickness of 3-5mm is used to facilitate adhesion to the inner wall of the pool. It has good absorption capacity for mega-level ultrasonic waves in water and can construct a free sound field.

[0017] Furthermore, by setting the ultrasonic sound-absorbing material into a sawtooth corrugated structure or a flat wedge channel structure, when the sound wave is incident along the wedge axis, its effect is equivalent to the sound impedance of water gradually transitioning to the sound impedance of the sound-absorbing material, thereby eliminating the interface of impedance abrupt change and significantly reducing the reflection coefficient.

[0018] In a second aspect, an example of this application provides a method for preparing an ultrasonic sound-absorbing material, comprising:

[0019] The raw materials, by mass parts, include 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder, and 6.5-8.5 parts of two-component room temperature vulcanizing silicone rubber; the two-component room temperature vulcanizing silicone rubber includes a main agent and a curing agent.

[0020] Mixing steps: Mix the main agent, expanded resin microspheres and tungsten powder, then add the curing agent to form a mixture;

[0021] Curing step: Place the mixture at 40-60℃ and cure for 12-24 hours.

[0022] In the above-described process, 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder, and 6.5-8.5 parts of the main component in a two-component room temperature vulcanizing silicone rubber are mixed evenly, then a curing agent is added. The mixture is then cured at 40-60°C for 12-24 hours to obtain a sound-absorbing material capable of absorbing mega-level ultrasound. The acoustic impedance of this ultrasonic sound-absorbing material is close to that of water, demonstrating good absorption capacity for mega-level ultrasound in water to meet the requirements of free sound field construction. Furthermore, the preparation method provided in this example is simple to operate, does not require heavy-duty mixing equipment for heating and pressure molding, and has low preparation costs.

[0023] In conjunction with the second aspect, in an optional embodiment of this application, the mixing step further includes: degassing the mixture.

[0024] In the above process, degassing the mixture during mixing can prevent the introduction of air bubbles into the ultrasonic sound-absorbing material, thereby improving the ultrasonic absorption capacity of the ultrasonic sound-absorbing material.

[0025] In conjunction with the second aspect, in an optional embodiment of this application, the curing step further includes: pressing the mixture into a mold and heating the mold to 40-60°C for 12-24 hours to cure.

[0026] In the above process, the mixture of raw materials for forming ultrasonic sound-absorbing material is pressed into a mold, and the mold is heated to 40-60℃ and cured for 12-24 hours to obtain ultrasonic sound-absorbing material with a predetermined shape and uniform size.

[0027] In conjunction with the second aspect, in an optional embodiment of this application, the mold is made of Teflon.

[0028] In the above process, the mold is made of Teflon so that the cured ultrasonic sound-absorbing material can be removed from the mold to obtain an ultrasonic sound-absorbing material of a preset shape and size. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0030] Figure 1 A schematic diagram of the sound-absorbing device provided as an example in this application;

[0031] Figure 2 A schematic diagram of the preparation process of the ultrasonic sound-absorbing material provided as an example in this application;

[0032] Figure 3 A schematic cross-sectional view of the first ultrasonic sound-absorbing material provided as an example of this application;

[0033] Figure 4 A cross-sectional schematic diagram of a second type of ultrasonic sound-absorbing material provided as an example in this application.

[0034] icon:

[0035] 100 - Sound-absorbing device; 101 - Water tank; 102 - Ultrasonic sound-absorbing material. Detailed Implementation

[0036] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0037] Currently, during the commissioning of the transducer sound field of an ultrasonic scanning device, the reflected waves generated by the four walls of the test pool often interfere with the measurement results, especially for the mega-frequency ultrasonic waves required by medical ultrasonic transducers, which may even make the test impossible.

[0038] Therefore, this application provides a sound-absorbing device 100 that has good absorption capability for mega-level ultrasound in water, can construct a free sound field, and meets the testing needs of ultrasonic transducers.

[0039] Please see Figure 1 The sound-absorbing device 100 includes a water tank 101 and an ultrasonic sound-absorbing material 102, which is attached to the inner wall of the water tank 101.

[0040] The ultrasonic sound-absorbing material 102 has a good absorption capacity for mega-level ultrasonic waves in water and its acoustic impedance is close to that of water, which can reduce the probability of ultrasonic waves emitted by the ultrasonic transducer forming emission waves at the inner wall of the water tank 101.

[0041] The water tank 101 and ultrasonic sound-absorbing material 102 in the sound-absorbing device 100 provided in this application will be described in further detail below with reference to the accompanying drawings.

[0042] This application does not limit the specific structure and material of the water tank 101, and relevant personnel can make corresponding adjustments according to the testing requirements.

[0043] In one possible implementation, the pool 101 can be a rectangular box-shaped structure.

[0044] In one possible implementation, the pool 101 can be an acrylic glass tank.

[0045] The ultrasonic sound-absorbing material 102 has a good absorption capacity for mega-level ultrasonic waves in water, which can reduce the probability of ultrasonic waves emitted by the ultrasonic transducer forming reflected waves at the inner wall of the water tank 101.

[0046] Please see Figure 2 This application provides an example of a method for preparing an ultrasonic sound-absorbing material 102, comprising:

[0047] S1. Obtaining raw materials

[0048] The raw materials, by weight, include 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder, and 6.5-8.5 parts of two-component room temperature vulcanizing silicone rubber; the two-component room temperature vulcanizing silicone rubber includes a main agent and a curing agent.

[0049] Among them, expanded resin microspheres refer to a type of commercially available thermoplastic hollow polymer microsphere composed of a thermoplastic polymer shell. These hollow spheres have an average diameter ranging from 20 to 50 μm and a density generally ranging from 25 to 130 kg / m³.

[0050] Expanded resin microspheres refer to foamed, thermally expanded resin microspheres. After thermal expansion, the volume of the resin microspheres remains essentially unchanged at room temperature.

[0051] Silicone vulcanizate (RTV) refers to a commercially available silicone elastomer that can be cured at room temperature or in a regular oven without the need for high temperature and high pressure, making it easy to use.

[0052] Silicone rubber can be classified into two-component room temperature vulcanizing (room temperature vulcanizing) rubber and one-component room temperature vulcanizing (room temperature vulcanizing) rubber according to its packaging method. Two-component room temperature vulcanizing rubber consists of separately packaged main agent and curing agent. The main agent and curing agent are mixed and can be cured at room temperature without heating or pressure.

[0053] The main component of two-component room temperature vulcanizing silicone rubber typically includes hydroxyl-terminated polysiloxanes, and the curing agent typically includes a catalyst and a crosslinking agent.

[0054] The catalyst is usually an organobismuth, organotitanium, or organotin composite catalyst. The organobismuth can be selected from bismuth triacetate, bismuth tripropionate, bismuth trivalerate, or bismuth triheptanoate, with bismuth triheptanoate being preferred. The organotitanium can be selected from bis(acetylacetonyl)diisopropoxytitanium, and the organotin can be selected from dibutyltin dilaurate.

[0055] The crosslinking agent may be selected from one or more of tetraethyl orthosilicate, propyl orthosilicate, polyethyl orthosilicate, and polymethyltriethoxysilane, or a mixture thereof.

[0056] This application does not limit the specific types of expanded resin microspheres and two-component room temperature vulcanizing silicone rubber; relevant personnel can make appropriate selections as needed.

[0057] For example, a two-component room temperature vulcanizing silicone rubber can be selected from Momentive.

[0058] For example, the expanded resin microspheres can be selected from Matsumoto Oils & Fats Co., Ltd.

[0059] Mixing 0.05-0.15 parts of expanded resin microspheres with 6.5-8.5 parts of two-component room temperature vulcanizing silicone rubber can significantly improve sound attenuation.

[0060] For example, the number of expanded resin microspheres can be one or any two of 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, 0.10 parts, 0.11 parts, 0.12 parts, 0.13 parts, 0.14 parts and 0.15 parts.

[0061] For example, the number of parts of the two-component room temperature vulcanizing silicone rubber can be one or a range between any two of 6.5 parts, 6.6 parts, 6.7 parts, 6.8 parts, 6.9 parts, 7.0 parts, 7.1 parts, 7.2 parts, 7.3 parts, 7.4 parts, 7.5 parts, 7.6 parts, 7.7 parts, 7.8 parts, 7.9 parts, 8.0 parts, 8.1 parts, 8.2 parts, 8.3 parts, 8.4 parts, and 8.5 parts.

[0062] Furthermore, this application does not limit the particle size of the expanded resin microspheres; relevant personnel can select the particle size of the expanded resin microspheres according to the required attenuation value.

[0063] For example, with the composition remaining unchanged, the larger the particle size of the expanded resin microspheres, the larger the corresponding attenuation coefficient, and vice versa.

[0064] In one possible embodiment, the particle size of the expanded resin microspheres can be 20-50 μm.

[0065] For example, the particle size of the expanded resin microspheres can be one of 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm and 50 μm or any combination thereof.

[0066] In the raw materials, relative to 0.05-0.15 parts of expanded resin microspheres, the addition of 15-25 parts of tungsten powder can control the acoustic impedance of the ultrasonic sound-absorbing material 102 within the range of 1.4-1.6 MRayls (a unit of acoustic impedance), which is basically consistent with the acoustic impedance of water, which is 1.48 MRayls.

[0067] For example, the number of parts of tungsten powder can be one of 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts and 25 parts or any combination thereof.

[0068] This application does not limit the specific amount of tungsten powder. Relevant personnel can adjust the ratio of tungsten powder and resin microspheres according to the requirements of acoustic impedance.

[0069] For example, to relatively increase impedance, the mass fraction of tungsten powder in the formulation can be increased. Conversely, to relatively decrease impedance, the mass fraction of tungsten powder in the formulation can be decreased.

[0070] For example, in order to relatively increase impedance, the raw material may contain 0.05-0.1 parts of expanded resin microspheres and 20-25 parts of tungsten powder.

[0071] For example, in order to relatively reduce impedance, the raw material may contain 0.1-0.15 parts of expanded resin microspheres and 15-20 parts of tungsten powder.

[0072] Furthermore, this application does not limit the specific particle size of the tungsten powder, and relevant personnel can make the appropriate selection as needed.

[0073] In one possible embodiment, the D50 particle size of the tungsten powder is 3-7 μm.

[0074] For example, the D50 particle size of tungsten powder can be one of 3 μm, 4 μm, 5 μm, 6 μm or 7 μm or any range between two of them.

[0075] For example, the D50 particle size of tungsten powder is 5 μm.

[0076] For further information, please refer to [link / reference]. Figure 2 The method for preparing ultrasonic sound-absorbing materials provided in this application also includes:

[0077] S2. Mixing Step: Mix the main agent, expanded resin microspheres and tungsten powder, and then add the curing agent to form a mixture.

[0078] The main agent, expanded resin microspheres and tungsten powder in the raw materials are mixed and then a curing agent is added to form a mixture, so that the mixture can be cured and molded to obtain ultrasonic sound absorbing material 102.

[0079] This application does not limit the specific mixing process of the mixture, and relevant personnel can make corresponding adjustments as needed.

[0080] In one possible implementation, the weighed, expanded resin microspheres can be placed into a container first. Then, the main agent can be slowly poured onto the top of the expanded resin microspheres in the container, and the main agent colloid can be slowly stirred to prevent a large number of expanded resin microspheres from floating up. After the resin microspheres have been basically stirred into the main agent, the colloid can be thoroughly stirred with a stirring rod.

[0081] Then, pour the weighed tungsten powder into the container, mix it evenly, and then use a dropper to add the RTV curing agent to the colloid, stir it thoroughly to form a mixture.

[0082] Furthermore, the mixture can be placed in a vacuum chamber and evacuated until it is essentially bubble-free. Alternatively, an automatic stirring and degassing machine can be used for stirring, mixing, and degassing.

[0083] For further information, please refer to [link / reference]. Figure 2 The method for preparing ultrasonic sound-absorbing materials provided in this application also includes:

[0084] S3. Curing step: Place the mixture in an oven at 40-60℃ and cure for 12-24 hours.

[0085] For example, the curing temperature can be 40°C, 45°C, 50°C, 55°C or 60°C.

[0086] For example, the curing time can be one or a range of any two of 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h or 24h.

[0087] For example, it is cured at 40°C for 24 hours.

[0088] For example, it is cured at 60°C for 12 hours.

[0089] Furthermore, in order to facilitate obtaining ultrasonic sound-absorbing material 102 of a predetermined shape and size, in one possible embodiment, the mixture can be pressed into a mold.

[0090] For example, place the frame on a glass mold covered with Teflon tape, and pour the sound-absorbing gasket adhesive into the gasket mold. Carefully and slowly place the upper glass plate along one side of the lower mold, avoiding the introduction of air bubbles.

[0091] To facilitate demolding, Teflon tape needs to be applied to the glass mold so that the ultrasonic sound-absorbing material 102 can be removed from the glass mold after curing.

[0092] Furthermore, after the mixture is poured, an iron press block is placed on top of the upper glass template to press the mixture, ensuring that the mixture can be evenly filled into different positions within the mold.

[0093] Furthermore, this application does not limit the specific structure of the ultrasonic sound-absorbing material 102. In one possible embodiment, please refer to... Figure 3 The ultrasonic sound-absorbing material 102 can be a sawtooth corrugated structure.

[0094] For example, the mixture is poured into a mold with a serrated corrugated structure.

[0095] Alternatively, in another possible implementation, please refer to Figure 4 The ultrasonic sound-absorbing material 102 can be a flat wedge channel structure.

[0096] By setting the ultrasonic sound-absorbing material 102 as a flat wedge channel structure, when the sound wave is incident along the wedge axis, its effect is equivalent to the sound impedance of water gradually transitioning to the sound impedance of the sound-absorbing material, thereby eliminating the interface of impedance abrupt change and significantly reducing the reflection coefficient.

[0097] Furthermore, this application does not limit the thickness of the ultrasonic sound-absorbing material 102, and relevant personnel can make corresponding adjustments as needed.

[0098] In one possible embodiment, the thickness of the ultrasonic sound-absorbing material 102 can be one or any combination of 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm.

[0099] Furthermore, during the curing process, the mold can be placed in an oven and heated to 40-60℃, and kept warm for 12-24 hours to form ultrasonic sound-absorbing material 102.

[0100] The ultrasonic sound-absorbing material 102 of this application will be further described in detail below with reference to the embodiments.

[0101] Example 1

[0102] Example 1 provides an ultrasonic sound-absorbing material 102, the preparation method of which is as follows:

[0103] (1) Raw material preparation: Refer to Table 1. Weigh 0.1g of expanded resin microspheres, 20g of tungsten powder, and 7.7g of two-component room temperature vulcanizing silicone rubber. The two-component room temperature vulcanizing silicone rubber is produced by Momentive (density approximately 1.3g / cc), the expanded resin microspheres are produced by Matsumoto Yushi Pharmaceutical Co., Ltd., the particle size of the expanded resin microspheres is 20-40μm, and the D50 particle size of the tungsten powder is 5μm.

[0104] (2) Mixing steps: After the expanded resin microspheres and the main agent in the two-component room temperature vulcanizing silicone rubber are mixed evenly using an automatic stirring degassing machine, tungsten powder is added and stirred evenly; then the curing agent in the two-component room temperature vulcanizing silicone rubber is added and stirred evenly to form a mixture.

[0105] (3) Curing step: Pour the mixture from step (2) into the mold and press for 30 minutes to ensure that the mixture is evenly filled into the mold. Then, place the mold in an oven and cure at 40°C for 24 hours to obtain ultrasonic sound-absorbing material 102.

[0106] Example 2

[0107] Example 2 provides an ultrasonic sound-absorbing material 102, which differs from Example 1 in that: in step (1), referring to Table 1, 0.15g of expanded resin microspheres, 15g of tungsten powder and 7.7g of two-component room temperature vulcanized silicone rubber are weighed.

[0108] Example 3

[0109] Example 3 provides an ultrasonic sound-absorbing material 102, which differs from Example 1 in that: in step (1), 0.06g of expanded resin microspheres, 24g of tungsten powder and 7.7g of two-component room temperature vulcanized silicone rubber are weighed.

[0110] Example 4

[0111] Example 4 provides an ultrasonic sound-absorbing material 102, which differs from Example 1 in that: in step (1), 0.12g of expanded resin microspheres, 20g of tungsten powder and 7.7g of two-component room temperature vulcanized silicone rubber are weighed.

[0112] Example 5

[0113] Example 5 provides an ultrasonic sound-absorbing material 102, which differs from Example 1 in that: in step (1), 0.1g of expanded resin microspheres, 18g of tungsten powder and 7.7g of two-component room temperature vulcanized silicone rubber are weighed.

[0114] Comparative Example 1

[0115] Comparative Example 1 provides an ultrasonic sound-absorbing material 102, which differs from Example 1 in that: in step (1), as shown in Table 1, the raw material includes 7.7g of two-component room temperature vulcanized silicone rubber.

[0116] Table 1

[0117] type Expanded resin microspheres / g Tungsten powder / g Two-component room temperature vulcanizing silicone rubber / g Example 1 0.1 20 7.7 Example 2 0.15 15 7.7 Example 3 0.06 24 7.7 Example 4 0.12 20 7.7 Example 5 0.1 18 7.7 Comparative Example 1 - - 7.7

[0118] Test case

[0119] The acoustic properties of the ultrasonic sound-absorbing materials provided in Examples 1-5 and Comparative Example 1 were measured. The test method referred to the pulse transmission insertion substitution method in water from the *Ultrasonic Handbook*, and the single-sample method was used to measure sound attenuation. Because the sound-absorbing material has significant attenuation, sound waves are difficult to detect after passing through the material; therefore, the thickness of the sound-absorbing material cannot be too thick. The single-sample method was used to measure sound attenuation, and the difference between the acoustic impedance and the water was used to compensate for the reflected portion. The reflection coefficient, calculated theoretically using acoustic impedance, is 0.019, resulting in a transmission coefficient of 0.981, indicating that sound waves can penetrate the material effectively.

[0120] The data measured from 0.5MHz to 1MHz were fitted to the curve y=k*f^b, resulting in k=22.06 and b=1.3647 for Example 1. The sound attenuation values ​​in Table 2 below were then calculated.

[0121] Table 2

[0122]

[0123] Results analysis:

[0124] Based on Examples 1-5, it can be seen that the ultrasonic sound-absorbing material provided in this application has good attenuation in the frequency range of 2-10MHz—that is, the design thickness of 3-5mm can completely attenuate the incident sound energy. Therefore, the performance comparison mainly focuses on how close it is to the underwater acoustic impedance of 1.48MRayls.

[0125] Combining Examples 1 and 2, it can be seen that in Example 2, the mass fraction of the expanded resin microspheres is relatively high, while the mass fraction of the tungsten powder is relatively low, and the acoustic impedance of the ultrasonic sound-absorbing material in Example 2 is significantly lower than 1.48.

[0126] As can be seen from Examples 1 and 3, the mass fraction of expanded resin microspheres is reduced, the mass fraction of tungsten powder is higher, and the acoustic impedance of the ultrasonic sound-absorbing material in Example 3 is significantly higher than 1.48.

[0127] Combining Examples 1 and 4 and 5, it can be seen that in Example 4, the amount of tungsten powder remained unchanged, the amount of expanded resin microspheres increased, and the acoustic impedance was relatively low; in Example 5, the amount of expanded resin microspheres remained unchanged, the amount of tungsten powder increased, and the acoustic impedance was relatively high.

[0128] In summary, it is evident that increasing the proportion of expanded resin microspheres reduces the acoustic impedance of the sound-absorbing material, while increasing the proportion of tungsten powder increases the acoustic impedance. Only a suitable ratio can better approximate the acoustic impedance of water. The ultrasonic sound-absorbing material 102 provided in this application is closer to the acoustic impedance of water and has a very small reflection coefficient, thus exhibiting relatively excellent sound attenuation performance.

[0129] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An ultrasonic sound absorbing material, characterized by, The raw material for forming the ultrasonic sound absorbing material comprises, by weight fraction, 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder and 6.5-8.5 parts of two-component room temperature vulcanized silicone rubber; the ultrasonic sound absorbing material is in a sawtooth corrugated structure or a flat wedge channel structure; the thickness of the ultrasonic sound absorbing material is 3-5 mm; the expanded resin microspheres are thermoplastic hollow polymer microspheres composed of a thermoplastic polymer shell, with a particle size of 20-50 μm and a density of 25-130 kg / m 3 ; the particle size of the tungsten powder is 3-7 μm; the two-component room temperature vulcanized silicone rubber comprises a main agent and a curing agent, the main agent comprises a hydroxyl-terminated polysiloxane; the curing agent comprises a catalyst and a crosslinking agent, the catalyst is an organic bismuth, organic titanium or organic tin composite catalyst; and the crosslinking agent is a mixture of one or more of tetraethyl orthosilicate, tripropyl orthosilicate, polyethyl orthosilicate or polymethyl triethoxysilane.

2. A method of preparing the ultrasonic sound absorbing material according to claim 1, characterized by, The method comprises: obtaining raw materials, the raw materials comprising, in terms of mass fraction, 0.05-0.15 parts of expanded resin microspheres, 15-25 parts of tungsten powder, and 6.5-8.5 parts of two-component room-temperature vulcanized silicone rubber; the two-component room-temperature vulcanized silicone rubber comprising a main agent and a curing agent; a mixing step: mixing the main agent, the expanded resin microspheres, and the tungsten powder, and then adding the curing agent to form a mixture; a curing step: curing the mixture at 40-60 ℃ for 12-24 h.

3. The preparation method according to claim 2, characterized in that, The mixing step further comprises: defoaming the mixture.

4. The production method according to claim 3, characterized by, The curing step further comprises: pressing the mixture in a mold, and curing the mold at 40-60 ℃ for 12-24 h.

5. The preparation method according to claim 4, characterized in that, The material of the mold is Teflon.

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