Method and device for promoting densification of sintered products using terahertz wave pre-treatment

Abstract

The application discloses a method for promoting sintered product densification by using terahertz wave pre-treatment, and the sintering is high-temperature sintering; before high-temperature sintering, the material (raw material powder, raw material particle or preform) for high-temperature sintering is pre-treated by using terahertz wave, so that the high-temperature sintered product densification is promoted, and the strength of the high-temperature sintered product is improved. The application also discloses a sintered product pre-treated by using terahertz wave and a device for promoting sintered product densification by using terahertz wave pre-treatment. The application applies terahertz technology to the material processing field mainly by high-temperature sintering; the material for high-temperature sintering is pre-treated by using non-contact and high-energy-efficiency terahertz wave, so that the product densification is promoted, and the product strength is improved. The method can be widely applied to the high-temperature sintering process in the fields of ceramics, metals, composite materials and the like; in addition to promoting product densification and improving product strength and the like, the method has remarkable energy-saving and consumption-reducing effects and economic benefits.

Description

Technical Field

[0001] This invention relates to the field of material processing, with high-temperature sintering as the main method, and in particular to a method and apparatus for promoting densification of sintered products by using terahertz wave pretreatment. Background Technology

[0002] High-temperature sintering is a crucial process in materials preparation, widely used in ceramics, metals, and composite materials. Traditional high-temperature sintering methods often suffer from high energy consumption, long cycles, and insufficient material densification. In particular, insufficient densification affects the strength of the product, thus impacting its performance.

[0003] Terahertz (THz) waves are electromagnetic waves with frequencies ranging from 0.1 to 10 THz (wavelengths of 30 to 3000 μm). The THz wave band covers the characteristic spectra of substances such as semiconductors, plasmas, organisms, and biological macromolecules. Utilizing this frequency band can deepen and expand human understanding of some fundamental scientific questions in physics, chemistry, astronomy, informatics, and life sciences.

[0004] Currently, several research institutions in China are conducting research in the terahertz field. However, most international and domestic research focuses solely on terahertz imaging and terahertz spectroscopy, applying transmission imaging and spectral measurement to areas such as short-range radar, satellite communication, remote sensing, homeland security and counter-terrorism, highly secure data communication and transmission, meteorological monitoring, security inspection, quality control, and biomedical diagnostics. There are currently no existing technologies for using terahertz wave pretreatment to promote densification of sintered products. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a method for promoting densification of sintered products, so that the densification of sintered products can be promoted through special pretreatment methods, thereby improving the strength of sintered products and thus improving the performance of sintered products.

[0006] The second technical problem to be solved by the present invention is to provide a sintered product that is densified, thereby increasing the strength of the sintered product and thus improving the performance of the sintered product.

[0007] The third technical problem to be solved by the present invention is to provide a dedicated device used in the above-described method.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for promoting densification of sintered products by using terahertz wave pretreatment, wherein the sintering is high-temperature sintering, and before high-temperature sintering, the material to be sintered at high temperature is pretreated with terahertz waves to promote densification of the high-temperature sintered product and improve the strength of the high-temperature sintered product; wherein the material to be sintered at high temperature is raw material powder, raw material particles or preforms.

[0010] As a further improvement of the present invention, the high-temperature sintered product is a high-temperature sintered product in the fields of ceramics, metals or composite materials.

[0011] Furthermore, in the pretreatment, the materials used for high-temperature sintering are treated with terahertz waves at a frequency of 0.1-10THz while being heated.

[0012] Furthermore, when the material is raw material powder or raw material particles, the processing temperature is 40-100℃ and the processing time is 1-3h; when the material is a preform, the processing temperature is 120-200℃ and the processing time is 2-4h.

[0013] Furthermore, the high-temperature sintered product is a refractory material slide plate; the pretreatment method is to pretreat the wet slide plate preform or raw material powder with terahertz waves, and then dry it before high-temperature sintering; or to dry the wet slide plate preform, pretreat it with terahertz waves, and then sinter it at high temperature.

[0014] Furthermore, the drying is performed at 200°C, and the high-temperature sintering is performed by calcination at 730°C.

[0015] Furthermore, the high-temperature sintered product is a ceramic tile; the pretreatment method involves pretreating some or all of the raw material powder of the ceramic tile with terahertz waves before high-temperature sintering, which can promote product densification, improve product strength, and reduce product thickness at the same time.

[0016] Furthermore, the raw material powder constitutes 3-10% by mass.

[0017] Secondly, the present invention provides a sintered product pretreated with terahertz waves, which is processed by the above-mentioned method of promoting densification of sintered products by terahertz wave pretreatment.

[0018] Thirdly, the present invention provides an apparatus for promoting densification of sintered products using terahertz wave pretreatment, the apparatus being the pretreatment apparatus used in the aforementioned method for promoting densification of sintered products using terahertz wave pretreatment; the pretreatment apparatus includes:

[0019] Main body of the device;

[0020] Terahertz energy chamber housed within the main body of the device;

[0021] A terahertz wave generator connected to the terahertz energy chamber to provide an energy source for the terahertz energy chamber;

[0022] It also includes an operation and control system for controlling the temperature inside the terahertz energy chamber and the duration of operation of the entire device.

[0023] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0024] (1) This invention applies terahertz technology to the field of material processing with high-temperature sintering as the main method; by using non-contact, high-efficiency terahertz waves to pretreat high-temperature sintered materials (raw material powder or preforms), it can promote product densification and improve product strength.

[0025] (2) The present invention uses a special device to generate terahertz waves of a specific frequency to pre-treat different materials with terahertz waves for different durations. In particular, temperature treatment is carried out at the same time as terahertz wave pre-treatment, which can change the microstructure and improve the thermal conductivity, thereby significantly improving the densification during the sintering process and enhancing the mechanical properties of the final product. In addition, it can also reduce sintering time and temperature.

[0026] (3) This method can be widely applied to high-temperature sintering processes in ceramics, metals, composite materials and other fields. In addition to promoting densification of sintered products and improving product strength and other properties, it also has significant energy-saving and consumption-reducing effects and economic benefits. Attached Figure Description

[0027] The above is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Figure 1 This is a schematic diagram of a method for promoting densification of sintered products using terahertz wave pretreatment in one embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the device structure for promoting densification of sintered products using terahertz wave pretreatment in Embodiment 1 of the present invention.

[0030] Figure 3 The structural diagram of the test product in Embodiment 2 of the present invention. Detailed Implementation

[0031] This invention breaks through the traditional application areas of terahertz technology, which are mainly based on terahertz imaging and terahertz spectroscopy, incorporating functions such as transmission imaging and spectral measurement. This invention, however, primarily applies terahertz technology to the field of material processing, where high-temperature sintering is the primary method; in conjunction with... Figure 1 As shown, before high-temperature sintering, the material (raw material powder, raw material particles, or preforms) is pretreated by non-contact, high-efficiency terahertz waves, which can promote product densification and improve product strength. High-temperature sintering in this invention refers to sintering at temperatures above 300°C.

[0032] Densification of sintered products is a process of forming a dense whole from powdered or granular materials through high-temperature treatment. During sintering, diffusion, fusion, and chemical reactions occur between particles, forming new substances or altering the microstructure. The densification effect depends on process parameters such as sintering temperature, time, and pressure, as well as the physical and chemical properties of the material.

[0033] Traditional methods for densification in sintering mainly include improving the chemical composition of the powder, increasing the density of the green body, increasing the sintering temperature, and extending the sintering time. Current technologies do not include research on using terahertz technology to promote densification of sintered products.

[0034] The mechanism by which terahertz wave pretreatment promotes sintering densification in this invention mainly includes:

[0035] 1. Improve the surface properties of materials

[0036] Terahertz waves can act on the surface of powder, change its surface activity, increase the number of surface active sites, and thus increase the activation energy of the powder surface, thereby improving the sintering activity of the powder.

[0037] 2. Enhance the diffusion of energy in matter.

[0038] Terahertz waves have strong penetrating power and can excite atoms or molecules in matter to achieve synchronous resonance, enhancing the diffusion ability of matter. This may change the sintering kinetics of powder, thereby promoting the diffusion and transport of matter during sintering.

[0039] 3. Optimize the microstructure of matter

[0040] Terahertz waves can optimize the microstructure of materials through molecular synchronous resonance, improve the physical and chemical properties of materials, and make them easier to form a uniform and dense body during sintering.

[0041] 4. Improved the thermal conductivity of the material

[0042] Terahertz waves possess high-frequency vibration and energy transfer characteristics. Therefore, through the interaction between high-frequency electromagnetic waves and materials, efficient energy transfer is achieved, enhancing the energy value and activity of molecules within the material, thereby improving the thermal and electrical conductivity of the material.

[0043] When terahertz wave treatment is combined with temperature treatment, the activity of the material itself can be stimulated, and the synergistic effect of the two is the best.

[0044] High-temperature sintering is a primary processing method for products in the fields of ceramics, metals, and composite materials. The working principle of using terahertz waves for pretreatment to promote densification and improve product strength is basically similar across various high-temperature sintering applications. Examples will be provided below:

[0045] Example 1: Apparatus for Promoting Densification of Sintered Products Using Terahertz Wave Pretreatment

[0046] This embodiment provides a dedicated pretreatment device, mainly used to pretreat materials for high-temperature sintering using terahertz waves, promoting product densification and improving product strength; in conjunction with Figure 2 The pretreatment device includes: a main body 1; a terahertz energy chamber 2 disposed within the main body 1; a terahertz wave generator 3 connected to the terahertz energy chamber 2 and providing an energy source for the terahertz energy chamber 2; and an operation control system for controlling the temperature inside the terahertz energy chamber and the entire operating time of the device.

[0047] The pretreatment device in this embodiment is a whole, including an independent terahertz energy chamber 2 and a terahertz wave generator 3. The independent energy chamber can act as a waveguide, enabling the terahertz wave generator 3 to generate stable terahertz waves of specific frequency and intensity, which are then precisely guided to the material to be treated (raw material powder, raw material particles, or preforms) within a certain space. At the same time, it is also equipped with an operation control system for the temperature inside the chamber and an operation control system for the action time of the terahertz wave generator, which can control the temperature and action time. Different temperatures and durations of pretreatment can be performed according to different materials to change the microstructure of the material, improve its thermal conductivity, improve the density of the product, and improve the mechanical properties such as the strength of the product.

[0048] The size and specifications of the aforementioned pretreatment equipment can be determined according to its intended use and production capacity requirements.

[0049] In actual preprocessing applications, the following steps can be followed:

[0050] Open the terahertz energy chamber 2, place the material to be pretreated (raw material powder, raw material particles, or preforms) into the center of the chamber, and close the chamber door. Depending on the pretreated material, select different temperatures on the control panel of the main unit, turn on the device, and set a certain time before shutting it off. This allows for control of the temperature inside the terahertz energy chamber and the action time of the terahertz wave generator through the operation control system. The temperature and duration settings are shown in Table 1.

[0051] Table 1 Temperature and time settings for different materials

[0052]

[0053] As shown in Table 1 above, for raw material powders, the temperature can be 40℃, 50℃, 60℃, 80℃, 100℃, etc., and the time can be 1h, 1.5h, 2h, 2.5h, 3h, etc. For preforms, the temperature can be 120℃, 150℃, 180℃, 200℃, etc., and the time can be 2-4h, such as 2h, 2.5h, 3h, 3.5h, 4h, etc.

[0054] During the pretreatment process, terahertz waves induce molecular synchronous resonance in the materials inside the chamber, thereby altering their microstructure, enhancing their thermal conductivity, improving product density, and increasing mechanical properties such as product strength.

[0055] Example 2: Refractory Material Slide Plate Test

[0056] 1. Test product

[0057] Refractory material skateboards (skateboard bricks), such as Figure 3 As shown.

[0058] 2. Test methods

[0059] A type of sliding plate brick was selected, and the strength changes of the brick blanks before and after terahertz wave pretreatment were studied, starting from the blank making (sliding plate wet blank prefabrication), the drying treatment at 200 degrees and the firing at 730 degrees. The pretreatment temperature here is 180 degrees and the treatment time is 2 hours.

[0060] Table 2. Unenhanced treatment (without terahertz wave pretreatment)

[0061] 1 After drying at 200℃ and exiting the kiln Perform room temperature performance tests 2 After drying at 200℃ and exiting the kiln After firing in a medium-temperature kiln, the indicators were tested. 3 Molded wet blank Perform room temperature performance tests 4 Molded wet blank After drying in the drying kiln, perform ambient temperature index tests. 2 Molded wet blank After drying, the parameters are tested after firing.

[0062] Table 3 Enhancement treatment (pretreated with terahertz waves)

[0063]

[0064] Referring to Tables 2 and 3 above, the experimental procedure is as follows:

[0065] (1) The workshop presses Ruifeng 350 sliding bricks, material b8-1 / SFB-3, brick batch number: 38LC48, mud batch number 38LC14, black material 1.8 kg, white material 4.68 kg.

[0066] (2) Take 6 wet blanks and 6 blanks that have been dried at 200 degrees Celsius in kiln No. 6. Take 4 blanks of each type and conduct terahertz wave pretreatment strengthening test. Keep the remaining 4 blanks for comparison and testing.

[0067] (3) After the sample bricks were pretreated by terahertz waves, subsequent processing was carried out. Slides No. 4, 8 and 9 were placed on slide car No. 110 and dried in the kiln at 200 degrees. Bricks No. 2, 6 (two pieces) and 9 were placed on the medium temperature kiln car and fired at 730 degrees. After firing, the bricks were cut and sampled for testing.

[0068] 3. Test Results

[0069] The test results are shown in Table 4 below:

[0070] Table 4 Test Results

[0071]

[0072]

[0073] As can be seen from Table 4 above:

[0074] (1) Scheme A: The strength of the slide plate sample is not significantly changed after drying at 200 degrees and then undergoing terahertz wave pretreatment.

[0075] (2) Option B: The slide plate sample was dried at 200 degrees and then pretreated with terahertz waves, and then fired at 730 degrees, which improved the strength by about 5-10%.

[0076] (3) Scheme C: The strength of the wet blank of the slide plate sample did not change whether it was pretreated with terahertz waves or not.

[0077] (4) Scheme D: The wet blank of the slide plate sample is pretreated with terahertz wave and then dried at 200 degrees, which increases the strength by about 10%.

[0078] (5) Scheme E: The wet blank of the slide plate sample is pretreated by terahertz wave, then dried at 200 degrees and fired at 730 degrees, which increases the strength by 15-17%, and the pretreatment effect is obvious.

[0079] 4. Experimental Conclusions

[0080] The results above show that terahertz wave pretreatment has little effect on improving the strength of the low-temperature treated slide plate. Terahertz wave pretreatment significantly improves the strength of the slide plate after high-temperature firing, increasing it by 15-17%; among them, pretreatment of the wet blank before drying results in a more significant strength improvement than pretreatment after drying.

[0081] It should be noted that the above embodiments use preforms as an example. In actual use, the raw material powder can also be pretreated to promote sintering and densification.

[0082] Example 3: Tile Test

[0083] 1. Test product

[0084] 800mm x 800mm floor tiles

[0085] 2. Test methods

[0086] Terahertz wave pretreatment is performed on 5% of the raw materials for ceramic tiles at 100℃ for 2 hours. Then, the thickness of the tile blank is reduced to 8mm (usually, the thickness of 800mm×800mm floor tiles should not be less than 10.5mm, otherwise their breaking strength and other indicators cannot meet the national standard requirements). Then, high-temperature sintering is carried out using the same process.

[0087] 3. Test Results

[0088] The 800mm×800mm×8mm ceramic tile pretreated with terahertz waves has a destructive strength and other indicators that are comparable to or better than those of the 10.5mm thick ceramic tile produced by Zhong Sheng Ceramics.

[0089] At the same time, a comparison product is provided: Dongpeng Ceramics has reduced the thickness of its 800mm×800mm tiles to 9mm through technological innovation, but many of its indicators are far inferior to the aforementioned 8mm tiles.

[0090] Table 5 Comparison of key performance indicators for three types of ceramic tiles

[0091]

[0092] 4. Experimental Conclusions

[0093] Terahertz wave pretreatment technology significantly improves several properties of ceramic tiles, including their destructive strength. Simultaneously, it can directly reduce the thickness of 800mm x 800mm tiles to 8mm. This not only saves over 20% of raw materials and reduces calcination energy consumption but also saves on transportation costs. Its economic benefits are considerable, and its environmental significance is immense.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, or alterations made by those skilled in the art using the disclosed technical content shall fall within the protection scope of the present invention.

Claims

1. A method for promoting densification of sintered products using terahertz wave pretreatment, characterized in that, The sintering is high-temperature sintering. Before high-temperature sintering, the materials used for high-temperature sintering are pretreated with terahertz waves to promote densification of the high-temperature sintered products and improve the strength of the high-temperature sintered products. The material used for high-temperature sintering is raw material powder, raw material particles, or preforms; In the pretreatment, the materials used for high-temperature sintering are treated with terahertz waves while being heated. When the material is raw material powder or raw material particles, the processing temperature is 40-100℃ and the processing time is 1-3h; when the material is preform, the processing temperature is 120-200℃ and the processing time is 2-4h.

2. The method for promoting densification of sintered products using terahertz wave pretreatment according to claim 1, characterized in that, The high-temperature sintered products are high-temperature sintered products in the fields of ceramics, metals, or composite materials.

3. The method for promoting densification of sintered products using terahertz wave pretreatment according to claim 1, characterized in that, In the preprocessing, terahertz waves with a frequency of 0.1-10 THz are used.

4. The method for promoting densification of sintered products using terahertz wave pretreatment according to any one of claims 1-3, characterized in that, The high-temperature sintered product is a refractory material sliding plate. The pretreatment method is to pretreat the wet preform of the slide plate or the raw material powder with terahertz waves, and then dry it before high-temperature sintering; or to pretreat the wet preform of the slide plate with terahertz waves after drying, and then sinter it at high temperature.

5. The method for promoting densification of sintered products using terahertz wave pretreatment according to claim 4, characterized in that, The drying process is carried out at 200°C, and the high-temperature sintering process is carried out at 730°C.

6. The method for promoting densification of sintered products using terahertz wave pretreatment according to any one of claims 1-3, characterized in that, The high-temperature sintered product is a ceramic tile; The pretreatment method involves pretreating some or all of the raw material powder of the ceramic tile with terahertz waves, followed by high-temperature sintering, which can promote product densification, improve product strength, and reduce product thickness at the same time.

7. The method for promoting densification of sintered products using terahertz wave pretreatment according to claim 6, characterized in that, The raw material powder mentioned above is 3-10% by mass.

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