Feeding and discharging method for ceramic machining and load bearing plate for feeding and discharging
By spraying a composite powder coating of materials such as yttrium-stabilized zirconium oxide, core-shell aluminum powder, and silicon carbide onto the sintering plate, the problems of adhesion and deformation at high temperatures were solved, and efficient automated loading and unloading and improved thermal shock resistance were achieved.
Patent Information
- Application Number
- CN202511797083.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-02
- Publication Date
- 2026-01-20
AI Technical Summary
Existing sintering plates tend to stick to the ceramic capacitor blank during high-temperature sintering, making it impossible to use a vacuum suction cup robot to pick them up, thus reducing production efficiency. At the same time, traditional materials are prone to deformation or cracking at high temperatures and have insufficient thermal shock resistance.
A composite powder coating consisting of yttrium-stabilized zirconium oxide, core-shell aluminum powder, silicon carbide, and binder is sprayed onto a corundum-mullite ceramic matrix. The coating is formed by plasma spraying technology, resulting in a high-temperature resistant and thermal shock resistant composite powder coating. Carbon nanotubes and borosilicate glass phases are introduced into the coating to improve mechanical strength and thermal stability.
This invention achieves a firing plate that does not deform or fail at high temperatures, and allows a vacuum suction cup robot arm to grasp the ceramic blank, improving production efficiency and significantly enhancing the mechanical properties and thermal shock resistance of the coating, thus preventing local overheating or cracking of the ceramic blank.
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Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of ceramic processing, in particular to a feeding and discharging method for ceramic processing and a supporting plate for feeding and discharging. BACKGROUND
[0002] The supporting plate is an important calcining kiln tool commonly used in the production sintering and glue removal process of sheet type multilayer ceramic capacitors. The existing supporting plate is mainly made of corundum-mullite ceramic material. In order to avoid destructive adhesion between the supporting plate and the ceramic capacitor blank during high-temperature sintering, an alumina powder is often used to separate the two. However, this causes the finished product to be unable to be grabbed by a machine hand with a vacuum suction cup after sintering, greatly reducing the production efficiency. In addition, the supporting plate not only needs to have high high-temperature resistance, but also needs to have excellent thermal shock resistance, which has a positive significance for rapid cooling and improving production efficiency. SUMMARY
[0003] The application aims at the above technical problems and provides a feeding and discharging method for ceramic processing and a supporting plate for feeding and discharging.
[0004] The technical scheme adopted is as follows: A supporting plate for feeding and discharging is composed of a corundum-mullite ceramic base and a coating. The coating is prepared from the following raw materials in parts by weight: Yttria-stabilized zirconia 28-32 parts, core-shell structure aluminum powder 20-25 parts, silicon carbide 50-60 parts, binder 1-3 parts, dispersant 0.1-1 parts, and solvent 30-40 parts. The core-shell structure aluminum powder is composed of aluminum microspheres, an organic carbon source coating layer, and a polydimethylsiloxane-boric acid layer.
[0005] Further, the organic carbon source coating layer contains a transition metal inorganic salt.
[0006] Further, the transition metal inorganic salt is a water-soluble iron salt, a water-soluble cobalt salt, a water-soluble nickel salt, a water-soluble copper salt, or a water-soluble zinc salt.
[0007] Further, the organic carbon source in the organic carbon source coating layer is phosphated polyethylene glycol.
[0008] Further, the phosphated polyethylene glycol is obtained by reacting polyethylene glycol and phosphorus oxychloride.
[0009] Further, the preparation method of the phosphated polyethylene glycol is as follows: Under a nitrogen atmosphere, polyethylene glycol and phosphorus oxychloride are added to acetonitrile, and after heating reaction, small molecules are removed by reduced pressure concentration.
[0010] Further, the preparation method of the core-shell structure aluminum powder is as follows: The aluminum microspheres are added into a first coating liquid containing phosphorized polyethylene glycol and a transition metal inorganic salt to perform coating to obtain an intermediate, and the intermediate is added into a second coating liquid containing polydimethylsiloxane-boric acid to perform coating to obtain the core-shell structure aluminum powder.
[0011] Further, the binder is a cellulose-based binder.
[0012] Further, the dispersant is ammonium polyacrylate and / or sodium polyphosphate.
[0013] Further, the preparation method of the supporting plate is as follows: The raw materials are mixed to obtain a slurry, the slurry is spray dried to obtain a composite powder, the composite powder is sprayed onto the surface of a corundum-mullite ceramic substrate through a plasma spraying device, and then vacuum heat treatment is performed.
[0014] Further, the vacuum heat treatment temperature is 800-900 DEG C.
[0015] The application further provides a loading and unloading method for ceramic processing. Specifically, the ceramic body to be fired is placed on the supporting plate, and after sintering is completed, a robot hand with a suction cup is used to grab the ceramic body to realize automatic loading and unloading.
[0016] Advantages of the application: The yttria-stabilized zirconia in the supporting plate has high thermal stability and mechanical strength, and is an oxide ceramic material, which is widely used in high-temperature surface protection. The decomposition temperature of silicon carbide is as high as 2700 DEG C, and it can work at an extreme high temperature of 1600-1800 DEG C for a long time, which is much higher than the material quality of traditional supporting plates. This feature enables it to cope with high-temperature sintering, molten metal processing and other scenes, and it will not deform or fail due to high temperature. Moreover, silicon carbide has high thermal conductivity and small thermal expansion coefficient, which can quickly and uniformly transfer the heat in the kiln, so that the body is heated more uniformly, reducing the deformation and cracking of the ceramic body caused by local overheating or temperature gradient. At the same time, its low expansion coefficient makes it not easy to crack due to thermal stress concentration during rapid cooling and heating, and its thermal shock resistance is significantly better than that of traditional supporting plate materials.
[0017] The introduction of aluminum powder can form an aluminum thermal reaction system with yttria-stabilized zirconia, and through rapid heating by plasma flame flow, elemental zirconium with extremely high activity is generated in-situ. The newly-born high-activity zirconium atoms immediately react with the carbon source (phosphorylated polyethylene glycol) to ultimately generate high-hardness ceramic phase zircon carbide that can withstand ultra-high temperatures, significantly improving the mechanical properties and high-temperature resistance of the coating. The phosphorylated polyethylene glycol not only participates in the aluminothermic reaction, but also generates carbon nanotubes under the catalysis of transition metal particles. These carbon nanotubes grow along the micro-pores formed by the pore-forming agent (polydimethylsiloxane-boric acid), improving the mechanical strength of the coating while improving the thermal shock resistance. The introduction of phosphorus can increase the residual carbon rate of polyethylene glycol, thereby providing more carbon source for the growth of carbon nanotubes and the formation of zircon carbide.
[0018] The polydimethylsiloxane-boric acid layer is both a pore-forming agent and decomposes to form micro-pores inside the coating when heated. The capillary action of these micro-pores is obvious, which can prevent the transmission of thermal stress from the inside to the outside of the sintered body, and is one of the effective ways to improve the thermal shock resistance. Moreover, the silicon and boron elements generated after decomposition can further react to form borosilicate glass phase. This glass phase has high chemical and thermal stability, can "anchor" or "support" the pores in the coating matrix, fill the micro-cracks around the pores, prevent the collapse of the pores, and improve the mechanical properties of the coating.
[0019] In addition, the present application also provides a loading and unloading method for ceramic processing. Compared with the prior art, the ceramic body to be fired can be directly placed on the supporting plate. Since no alumina powder is needed for isolation, the sintered body can be automatically loaded and unloaded by a robot with a suction cup after sintering, greatly improving the production efficiency. DETAILED DESCRIPTION
[0020] Unless otherwise specified, the specific conditions in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, but are conventional products that can be purchased on the market. The techniques not mentioned in the present application refer to the prior art. Unless otherwise specified, the following examples and comparative examples are parallel tests using the same processing steps and parameters.
[0021] Example 1: A supporting plate for loading and unloading, which is composed of a corundum-mullite ceramic matrix and a coating; The coating is prepared from the following raw materials in parts by weight: Yttria-stabilized zirconia 30 parts, core-shell structure aluminum powder 22 parts, silicon carbide 55 parts, sodium carboxymethyl cellulose 2 parts, sodium polyphosphate 0.5 parts, deionized water 35 parts; The core-shell structure aluminum powder is composed of aluminum microspheres, an organic carbon source coating layer, and a polydimethylsiloxane-boric acid layer. The preparation method is as follows: The polyethylene glycol 1000, the phosphorus oxychloride and the acetonitrile with a mass ratio of 1:0.02:10 are weighed, the polyethylene glycol 1000 is dissolved in the acetonitrile at room temperature under nitrogen protection, then the phosphorus oxychloride is added, stirring to dissolve, the temperature is raised to 60 DEG C, constant temperature reaction is carried out for 8 hours, then reduced pressure concentration is carried out, then the room temperature is recovered, and the polyethylene glycol phosphide is obtained. The phosphide polyethylene glycol, the cobalt nitrate and the ethanol with a mass ratio of 1:0.02:10 are weighed, the phosphide polyethylene glycol and the cobalt nitrate are dissolved in the ethanol to obtain a first coating solution, the aluminum microspheres with a particle size of 1-5 microns are added into the first coating solution according to a solid-liquid mass ratio of 1:5 to obtain a first mixed solution, the first mixed solution is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the ethanol is removed by reduced pressure concentration to obtain an intermediate. The polydimethylsiloxane, the boric acid and the diethyl ether with a mass ratio of 1.5:1:10 are weighed, the polydimethylsiloxane and the boric acid are dissolved in the diethyl ether, heating is carried out to reflux, reaction is carried out for 2 hours to obtain a second coating solution, the intermediate is added into the second coating solution according to a solid-liquid mass ratio of 1:5 to obtain a second mixed solution, the second mixed solution is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the diethyl ether is removed by reduced pressure concentration to obtain the aluminum powder with a core-shell structure.
[0022] The preparation method of the above supporting plate is as follows: The corundum-mullite ceramic substrate surface is polished, cleaned and dried; the yttria-stabilized zirconia, the aluminum powder with a core-shell structure, the silicon carbide, the sodium carboxymethyl cellulose, the sodium polyphosphate and the deionized water are mixed to obtain a slurry, the slurry is spray dried to obtain a composite powder, the composite powder is sprayed onto the corundum-mullite ceramic substrate surface through a plasma spraying device, the plasma spraying process parameters are as follows: current 550 A, voltage 60 V, main gas argon flow rate 50 L / min, auxiliary gas hydrogen flow rate 15 L / min, spraying distance 50 mm, powder feeding rate 0.2 g / s, then the supporting plate is sent into a vacuum tube furnace for heat treatment at 850 DEG C for 60 min to obtain a coating with a thickness of 3.2 mm.
[0023] Example 2: A supporting plate for feeding and discharging is composed of a corundum-mullite ceramic substrate and a coating. The coating is prepared from the following raw materials in parts by weight: The yttria-stabilized zirconia 32 parts, the aluminum powder with a core-shell structure 25 parts, the silicon carbide 60 parts, the sodium carboxymethyl cellulose 3 parts, the sodium polyphosphate 1 part and the deionized water 40 parts; The aluminum powder with a core-shell structure is composed of aluminum microspheres, an organic carbon source coating layer and a polydimethylsiloxane-boric acid layer, and the preparation method is as follows: The polyethylene glycol 1000, the phosphorus oxychloride and the acetonitrile with a mass ratio of 1:0.02:10 are weighed, the polyethylene glycol 1000 is dissolved in the acetonitrile at room temperature under nitrogen protection, then the phosphorus oxychloride is added, stirring to dissolve, and then the temperature is raised to 60 DEG C, constant temperature reaction is carried out for 8 hours, and then vacuum concentration is carried out, and then the room temperature is recovered to obtain the phosphorus polyethylene glycol. The phosphorus polyethylene glycol, the cobalt nitrate and the ethanol with a mass ratio of 1:0.02:10 are weighed, the phosphorus polyethylene glycol and the cobalt nitrate are dissolved in the ethanol to obtain a first coating liquid, the aluminum microspheres with a particle size of 1-5 microns are added into the first coating liquid according to a solid-liquid mass ratio of 1:5 to obtain a first mixed liquid, the first mixed liquid is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the ethanol is removed by vacuum concentration to obtain an intermediate. The polydimethylsiloxane, the boric acid and the diethyl ether with a mass ratio of 1.5:1:10 are weighed, the polydimethylsiloxane and the boric acid are dissolved in the diethyl ether, and then the temperature is raised to reflux to react for 2 hours to obtain a second coating liquid. The intermediate is added into the second coating liquid according to a solid-liquid mass ratio of 1:5 to obtain a second mixed liquid. The second mixed liquid is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the diethyl ether is removed by vacuum concentration to obtain the core-shell structure aluminum powder.
[0024] The preparation method of the above supporting plate is as follows: The corundum-mullite ceramic substrate surface is polished, cleaned and dried. The yttria-stabilized zirconia, the core-shell structure aluminum powder, the silicon carbide, the sodium carboxymethyl cellulose, the sodium polyphosphate and the deionized water are mixed to obtain a slurry. The slurry is spray dried to obtain a composite powder. The composite powder is sprayed onto the corundum-mullite ceramic substrate surface by a plasma spraying device. The plasma spraying process parameters are as follows: current 550 A, voltage 60 V, main gas argon flow rate 50 L / min, auxiliary gas hydrogen flow rate 15 L / min, spraying distance 50 mm, and powder feeding rate 0.2 g / s. Subsequently, the supporting plate is sent into a vacuum tube furnace for heat treatment at 900 DEG C for 60 min to obtain a coating layer with a thickness of 3.2 mm.
[0025] Example 3: A supporting plate for feeding and discharging is composed of a corundum-mullite ceramic substrate and a coating layer. The coating layer is prepared from the following raw materials in parts by weight: The yttria-stabilized zirconia 28 parts, the core-shell structure aluminum powder 20 parts, the silicon carbide 50 parts, the sodium carboxymethyl cellulose 1 part, the sodium polyphosphate 0.1 part and the deionized water 30 parts. The core-shell structure aluminum powder is composed of aluminum microspheres, an organic carbon source coating layer and a polydimethylsiloxane-boric acid layer. The preparation method is as follows: The polyethylene glycol 1000, the phosphorus oxychloride and the acetonitrile with a mass ratio of 1:0.02:10 are weighed, the polyethylene glycol 1000 is dissolved in the acetonitrile at room temperature under nitrogen protection, then the phosphorus oxychloride is added, stirring to dissolve, the temperature is raised to 60 DEG C, constant temperature reaction is carried out for 8 hours, then reduced pressure concentration is carried out, then the room temperature is recovered, and the polyethylene glycol phosphide is obtained. The phosphide polyethylene glycol, the cobalt nitrate and the ethanol with a mass ratio of 1:0.02:10 are weighed, the phosphide polyethylene glycol and the cobalt nitrate are dissolved in the ethanol to obtain a first coating solution, the aluminum microspheres with a particle size of 1-5 microns are added into the first coating solution according to a solid-liquid mass ratio of 1:5 to obtain a first mixed solution, the first mixed solution is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the ethanol is removed by reduced pressure concentration to obtain an intermediate. The polydimethylsiloxane, the boric acid and the diethyl ether with a mass ratio of 1.5:1:10 are weighed, the polydimethylsiloxane and the boric acid are dissolved in the diethyl ether, the temperature is raised to reflux, reaction is carried out for 2 hours to obtain a second coating solution, the intermediate is added into the second coating solution according to a solid-liquid mass ratio of 1:5 to obtain a second mixed solution, the second mixed solution is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the diethyl ether is removed by reduced pressure concentration to obtain the aluminum powder with a core-shell structure.
[0026] The preparation method of the above supporting plate is as follows: The surface of the corundum-mullite ceramic substrate is polished, cleaned and dried; the yttria-stabilized zirconia, the aluminum powder with a core-shell structure, the silicon carbide, the sodium carboxymethyl cellulose, the sodium polyphosphate and the deionized water are mixed to obtain a slurry, the slurry is spray dried to obtain a composite powder, the composite powder is sprayed onto the surface of the corundum-mullite ceramic substrate through a plasma spraying device, the plasma spraying process parameters are as follows: current 550 A, voltage 60 V, main gas argon flow rate 50 L / min, auxiliary gas hydrogen flow rate 15 L / min, spraying distance 50 mm, powder feeding rate 0.2 g / s, and then the supporting plate is sent into a vacuum tube furnace for heat treatment at 800 DEG C for 60 min to obtain a coating layer with a thickness of 3.2 mm.
[0027] Example 4: A supporting plate for feeding and discharging is composed of a corundum-mullite ceramic substrate and a coating layer. The coating layer is prepared from the following raw materials in parts by weight: The yttria-stabilized zirconia 32 parts, the aluminum powder with a core-shell structure 20 parts, the silicon carbide 60 parts, the sodium carboxymethyl cellulose 1 part, the sodium polyphosphate 1 part and the deionized water 30 parts; The aluminum powder with a core-shell structure is composed of aluminum microspheres, an organic carbon source coating layer and a polydimethylsiloxane-boric acid layer, and the preparation method is as follows: The polyethylene glycol 1000, the phosphorus oxychloride and the acetonitrile with a mass ratio of 1:0.02:10 are weighed, the polyethylene glycol 1000 is dissolved in the acetonitrile at room temperature under nitrogen protection, then the phosphorus oxychloride is added, stirring to dissolve, and then the temperature is raised to 60 DEG C, constant temperature reaction is carried out for 8 hours, and then vacuum concentration is carried out, and then the room temperature is recovered to obtain the phosphorus polyethylene glycol. The phosphorus polyethylene glycol, the cobalt nitrate and the ethanol with a mass ratio of 1:0.02:10 are weighed, the phosphorus polyethylene glycol and the cobalt nitrate are dissolved in the ethanol to obtain a first coating liquid, the aluminum microspheres with a particle size of 1-5 microns are added into the first coating liquid according to a solid-liquid mass ratio of 1:5 to obtain a first mixed liquid, the first mixed liquid is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the ethanol is removed by vacuum concentration to obtain an intermediate. The polydimethylsiloxane, the boric acid and the diethyl ether with a mass ratio of 1.5:1:10 are weighed, the polydimethylsiloxane and the boric acid are dissolved in the diethyl ether, and then the temperature is raised to reflux to react for 2 hours to obtain a second coating liquid. The intermediate is added into the second coating liquid according to a solid-liquid mass ratio of 1:5 to obtain a second mixed liquid. The second mixed liquid is loaded into a flask, water bath heating is carried out on a rotary evaporator, and the diethyl ether is removed by vacuum concentration to obtain the core-shell structure aluminum powder.
[0028] The preparation method of the above supporting plate is as follows: The corundum-mullite ceramic substrate surface is polished, cleaned and dried. The yttria-stabilized zirconia, the core-shell structure aluminum powder, the silicon carbide, the sodium carboxymethyl cellulose, the sodium polyphosphate and the deionized water are mixed to obtain a slurry. The slurry is spray dried to obtain a composite powder. The composite powder is sprayed onto the corundum-mullite ceramic substrate surface by a plasma spraying device. The plasma spraying process parameters are as follows: current 550 A, voltage 60 V, main gas argon flow rate 50 L / min, auxiliary gas hydrogen flow rate 15 L / min, spraying distance 50 mm, and powder feeding rate 0.2 g / s. Subsequently, the supporting plate is sent into a vacuum tube furnace for heat treatment at 850 DEG C for 60 min to obtain a coating layer with a thickness of 3.2 mm.
[0029] Example 5: A supporting plate for feeding and discharging is composed of a corundum-mullite ceramic substrate and a coating layer. The coating layer is prepared from the following raw materials in parts by weight: The yttria-stabilized zirconia 28 parts, the core-shell structure aluminum powder 25 parts, the silicon carbide 50 parts, the sodium carboxymethyl cellulose 3 parts, the sodium polyphosphate 0.1 parts and the deionized water 40 parts. The core-shell structure aluminum powder is composed of aluminum microspheres, an organic carbon source coating layer and a polydimethylsiloxane-boric acid layer. The preparation method is as follows: Take the mass ratio of 1:0.02:10 of polyethylene glycol 1000, phosphorus oxychloride and acetonitrile, nitrogen protection, first polyethylene glycol 1000 is dissolved in acetonitrile at room temperature, then phosphorus oxychloride is added, stirring to dissolve, then the temperature is raised to 60℃, constant temperature reaction 8h, then reduced pressure concentration, then restore room temperature to obtain phosphorus polyethylene glycol. Take the mass ratio of 1:0.02:10 of phosphorus polyethylene glycol, cobalt nitrate and ethanol, dissolve the phosphorus polyethylene glycol and cobalt nitrate in ethanol to obtain the first coating liquid, add the aluminum microspheres with a particle size of 1-5μm to the first coating liquid according to the solid-liquid mass ratio of 1:5 to obtain the first mixed liquid, put the first mixed liquid into a flask, heat in water bath on the rotary evaporator to remove ethanol under reduced pressure to obtain an intermediate, take the mass ratio of 1.5:1:10 of polydimethylsiloxane, boric acid and diethyl ether, dissolve the polydimethylsiloxane and boric acid in diethyl ether, then heat to reflux for 2h to obtain a second coating liquid, add the intermediate to the second coating liquid according to the solid-liquid mass ratio of 1:5 to obtain a second mixed liquid, put the second mixed liquid into a flask, heat in water bath on the rotary evaporator to remove diethyl ether under reduced pressure to obtain the core-shell structure aluminum powder.
[0030] The preparation method of the above supporting plate is as follows: The surface of the corundum-mullite ceramic substrate is polished, cleaned and dried; yttria-stabilized zirconia, core-shell structure aluminum powder, silicon carbide, sodium carboxymethyl cellulose, sodium polyphosphate and deionized water are mixed to obtain a slurry, and the slurry is spray dried to obtain a composite powder. The composite powder is sprayed onto the surface of the corundum-mullite ceramic substrate by a plasma spraying device. The plasma spraying process parameters are: current 550A, voltage 60V, main gas argon flow rate 50L / min, auxiliary gas hydrogen flow rate 15L / min, spraying distance 50mm, powder feeding rate 0.2g / s. Then it is sent into a vacuum tube furnace for heat treatment at 850℃ for 60min to obtain a coating layer with a thickness of 3.2mm.
[0031] Comparative Example 1: The same as Example 1, except that the aluminum microspheres with a particle size of 1-5μm are used instead of the core-shell structure aluminum powder.
[0032] A supporting plate for feeding and discharging, which is composed of a corundum-mullite ceramic substrate and a coating layer; The coating layer is prepared from the following raw materials in parts by weight: Yttria-stabilized zirconia 30 parts, aluminum microspheres 22 parts, silicon carbide 55 parts, sodium carboxymethyl cellulose 2 parts, sodium polyphosphate 0.5 parts, deionized water 35 parts; The preparation method of the above supporting plate is as follows: The surface of the corundum-mullite ceramic substrate is polished, cleaned and dried; yttria-stabilized zirconia, aluminum microspheres, silicon carbide, sodium carboxymethyl cellulose, sodium polyphosphate and deionized water are mixed to obtain a slurry, the slurry is spray dried to obtain a composite powder, the composite powder is sprayed onto the surface of the corundum-mullite ceramic substrate by a plasma spraying device, the plasma spraying process parameters are: current 550 A, voltage 60 V, main gas argon flow rate 50 L / min, auxiliary gas hydrogen flow rate 15 L / min, spraying distance 50 mm, powder feeding rate 0.2 g / s, and then it is sent into a vacuum tube furnace for heat treatment at 850℃ for 60 min to obtain a coating with a thickness of 3.2 mm.
[0033] Comparative Example 2: The same as Example 1, except that the core-shell structure aluminum powder does not contain an organic carbon source coating layer.
[0034] A supporting plate for loading and unloading, which is composed of a corundum-mullite ceramic substrate and a coating; The coating is prepared from the following raw materials in parts by weight: Yttria-stabilized zirconia 30 parts, core-shell structure aluminum powder 22 parts, silicon carbide 55 parts, sodium carboxymethyl cellulose 2 parts, sodium polyphosphate 0.5 parts, deionized water 35 parts; The core-shell structure aluminum powder is composed of aluminum microspheres and a polydimethylsiloxane-boric acid layer, and the preparation method is as follows: Polydimethylsiloxane, boric acid and diethyl ether are weighed in a mass ratio of 1.5:1:10, the polydimethylsiloxane and boric acid are dissolved in diethyl ether, then the mixture is heated to reflux for 2 hours to obtain a coating liquid, aluminum microspheres with a particle size of 1-5 μm are added to the coating liquid in a solid-liquid mass ratio of 1:5 to obtain a mixed liquid, and the mixed liquid is placed in a flask and concentrated under reduced pressure on a rotary evaporator to remove diethyl ether, thereby obtaining a core-shell structure aluminum powder.
[0035] The preparation method of the above supporting plate is as follows: The surface of the corundum-mullite ceramic substrate is polished, cleaned and dried; yttria-stabilized zirconia, core-shell structure aluminum powder, silicon carbide, sodium carboxymethyl cellulose, sodium polyphosphate and deionized water are mixed to obtain a slurry, the slurry is spray dried to obtain a composite powder, the composite powder is sprayed onto the surface of the corundum-mullite ceramic substrate by a plasma spraying device, the plasma spraying process parameters are: current 550 A, voltage 60 V, main gas argon flow rate 50 L / min, auxiliary gas hydrogen flow rate 15 L / min, spraying distance 50 mm, powder feeding rate 0.2 g / s, and then it is sent into a vacuum tube furnace for heat treatment at 850℃ for 60 min to obtain a coating with a thickness of 3.2 mm.
[0036] Comparative Example 3: The same as Example 1, except that the core-shell structure aluminum powder does not contain a polydimethylsiloxane-boric acid layer.
[0037] A loading and unloading supporting plate is composed of corundum-mullite ceramic matrix and coating; The coating is prepared from the following raw materials in parts by weight: 30 parts of yttria-stabilized zirconia, 22 parts of core-shell structure aluminum powder, 55 parts of silicon carbide, 2 parts of sodium carboxymethyl cellulose, 0.5 parts of sodium polyphosphate, and 35 parts of deionized water; The core-shell structure aluminum powder is composed of aluminum microspheres and an organic carbon source coating layer, and is prepared by the following method: Take 1:0.02:10 mass ratio of polyethylene glycol 1000, phosphorus oxychloride and acetonitrile, and dissolve the polyethylene glycol 1000 in acetonitrile at room temperature under nitrogen protection, then add phosphorus oxychloride, stir to dissolve, and then raise the temperature to 60℃, and react for 8h under constant temperature, then reduce the pressure to concentrate, and then restore the room temperature to obtain phosphonated polyethylene glycol. Take 1:0.02:10 mass ratio of phosphonated polyethylene glycol, cobalt nitrate and ethanol, dissolve the phosphonated polyethylene glycol and cobalt nitrate in ethanol to obtain a coating liquid, add 1-5μm aluminum microspheres to the coating liquid according to a solid-liquid mass ratio of 1:5 to obtain a mixed liquid, and then pour the mixed liquid into a flask, heat in a water bath on a rotary evaporator, and reduce the pressure to concentrate to remove ethanol to obtain the core-shell structure aluminum powder.
[0038] The preparation method of the above supporting plate is as follows: Grind and clean the surface of the corundum-mullite ceramic matrix and dry it; mix yttria-stabilized zirconia, core-shell structure aluminum powder, silicon carbide, sodium carboxymethyl cellulose, sodium polyphosphate and deionized water to obtain a slurry, spray dry the slurry to obtain a composite powder, spray the composite powder onto the surface of the corundum-mullite ceramic matrix through a plasma spraying device, and the plasma spraying process parameters are as follows: current 550A, voltage 60V, main gas argon flow rate 50L / min, auxiliary gas hydrogen flow rate 15L / min, spraying distance 50mm, powder feeding rate 0.2g / s, and then send into a vacuum tube furnace for heat treatment at 850℃ for 60min to obtain a coating with a thickness of 3.2mm.
[0039] Performance test In order to facilitate the test, graphite matrix is used to replace the corundum-mullite ceramic matrix in the examples 1-5 and comparative examples 1-3 to prepare test samples, a nanoindentation tester is used to test the elastic modulus and hardness of the coating on the surface of the sample, the hardness of each sample is measured at four corners of the coating and the middle position of the coating, and the average value is taken as the average hardness of the coating.
[0040] The ratio of the hardness of the material to the elastic modulus can be used as a brittleness index of the material, which reflects the degree of elastic response of the elastic-plastic material. The greater the ratio of the hardness of the material to the elastic modulus, the greater the brittleness of the material, and the worse the toughness. Conversely, the better the toughness. In the present test, the ratio of the hardness to the elastic modulus, i.e. the brittleness index, is used to represent the toughness of the coating.
[0041] The samples are also heated at 1000℃ and held for 10min, and then put into 5℃ cold water to observe whether there are cracks or peeling on the surface of the coating, and the anti-failure ability is measured by continuous cycling.
[0042] The results of the above tests are shown in Table 1 below: Table 1: From the above Table 1, it can be seen that the coating on the present application's supporting plate shows a lower brittleness index, higher toughness and better thermal shock resistance.
[0043] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A loading and unloading supporting plate, characterized by, Consist of corundum-mullite ceramic matrix and coating; The coating is prepared from the following raw materials in parts by weight: Yttria stabilized zirconia 28-32 parts, core-shell structure aluminum powder 20-25 parts, silicon carbide 50-60 parts, binder 1-3 parts, dispersant 0.1-1 parts, solvent 30-40 parts; The core-shell structure aluminum powder consists of aluminum microspheres, organic carbon source coating layer and polydimethylsiloxane-boric acid layer.
2. The loading and unloading supporting plate according to claim 1, wherein The organic carbon source coating layer contains transition metal inorganic salt.
3. The loading and unloading supporting plate according to claim 2, wherein The organic carbon source in the organic carbon source coating layer is phosphated polyethylene glycol.
4. The loading and unloading supporting plate according to claim 3, wherein The phosphated polyethylene glycol is obtained by the reaction of polyethylene glycol and phosphorus oxychloride.
5. The loading and unloading supporting plate according to claim 4, wherein The preparation method of the core-shell structure aluminum powder is as follows: The aluminum microspheres are coated in a first coating liquid containing phosphated polyethylene glycol and transition metal inorganic salt to obtain an intermediate, and the intermediate is coated in a second coating liquid containing polydimethylsiloxane-boric acid to obtain the core-shell structure aluminum powder.
6. The loading and unloading support plate according to claim 1, wherein The binder is a cellulose-based binder.
7. The loading and unloading support plate according to claim 1, wherein The dispersant is ammonium polyacrylate and / or sodium polyphosphate.
8. The loading and unloading supporting plate according to claim 1, wherein The preparation method of the supporting plate is as follows: The raw materials are mixed to obtain a slurry, the slurry is spray dried to obtain a composite powder, the composite powder is sprayed onto the surface of the corundum-mullite ceramic matrix by a plasma spraying device, and then vacuum heat treatment is performed.
9. The loading and unloading supporting plate according to claim 8, wherein The vacuum heat treatment temperature is 800-900℃.
10. A method for loading and unloading of ceramic processing, characterized by, The ceramic body to be fired is placed on the supporting plate according to any one of claims 1-9, and after sintering is completed, a machine hand with a suction cup is used to grab it to realize automatic feeding and discharging.