Light-storing luminescent ceramic material and method for producing the same

Abstract

The application discloses a light-storing luminescent ceramic material and a preparation method thereof, relates to the technical field of inorganic non-metallic materials, and is the final product of the preparation method of the light-storing luminescent ceramic material, and the preparation method comprises the following steps: step 1, powder pretreatment; step 2, warm-pressing forming; step 3, demoulding and deburring; step 4, one-time sintering; step 5, controlled cooling and post-treatment; and step 6, detection and packaging. According to the innovative 'warm-pressing + one-time sintering' synergistic process, the light-storing phase is efficiently activated, the ceramic matrix is nearly fully densified, and the ultrafine crystal structure is simultaneously constructed under the premise that the equipment investment and the process complexity are not significantly increased, so that the light-storing luminescent ceramic material with high luminescent performance, excellent mechanical strength and long-term environmental stability is obtained; meanwhile, the process of the application is compatible with the existing production line and has excellent industrialization prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inorganic non-metallic materials, and particularly relates to a light-storing luminescent ceramic material and a preparation method thereof. BACKGROUND

[0002] As an important branch of functional ceramics, light-storing luminescent ceramic materials have shown irreplaceable application value in many fields such as safety signs, emergency lighting, building decoration and low-illumination environment display, due to their unique performance of continuously releasing visible light after the excitation light source is removed. Compared with traditional fluorescent coatings or organic luminescent materials, the ceramic matrix endows the material with excellent thermal stability, chemical inertness and mechanical durability, so that the material can serve in complex or even harsh outdoor or industrial environments for a long time. Therefore, how to further improve the luminescent efficiency and prolong the afterglow time of the material while ensuring the integrity of the material structure, and to realize a low-cost, high-consistency and scalable preparation process, has become one of the core issues of the current engineering research of functional ceramic materials. In recent years, with the continuous improvement of infrastructure construction and public safety standards in smart cities, the market has put forward more urgent demands for light-storing luminescent ceramics with high brightness, long afterglow, strong weather resistance and suitable for mass production, which directly promotes the accelerated evolution of related preparation technologies from laboratory exploration to industrialization.

[0003] In the existing technical path, some schemes attempt to realize the integration design of structure and function through advanced forming means, by adopting ceramic powder and high-proportion long-afterglow luminescent material, and assisting with a binder and a solvent to construct a printable slurry system. This method effectively avoids the limitation of traditional dry pressing or grouting process on complex geometric shapes in principle, realizes the rapid forming of customized components, and to some extent, retains the optical activity of the luminescent component. However, this technical route faces double constraints in industrial application: on the one hand, the high-doped luminescent phase is prone to form agglomeration or local enrichment in the ceramic matrix, resulting in the decrease of microstructure uniformity, and then causing the uneven distribution of luminescent intensity and the fluctuation of afterglow decay rate; on the other hand, the high dependence of 3D printing on equipment precision, environmental temperature and humidity, and slurry rheological properties significantly raises the investment threshold and process control difficulty of the production line, which is difficult to meet the basic requirements of cost-effectiveness and process stability for large-scale and continuous production. Accordingly, although it has certain advantages in prototype manufacturing or small-batch special parts field, it is still weak in the industrialization popularization of general light-storing luminescent ceramic products.

[0004] Another type of technical idea focuses on the in-situ synthesis and sintering process optimization of the luminescent component, by doping alkali earth metal oxides, aluminum oxides, salts and The luminescent ceramics with afterglow time over 12 hours were successfully prepared by high-temperature sintering of the mixed oxides with specific stoichiometric ratio. The key of this method is to select the precursor with extremely low gas release during thermal decomposition, which effectively suppresses the surface bubbling defects caused by the escape of volatile substances during sintering, and significantly improves the surface finish and appearance quality of the finished product. However, in-depth analysis of the essence of the process shows that such in-situ synthesis strategy puts extremely strict requirements on the sintering regime, especially the precise control of temperature curve and reducing atmosphere. The stable existence of the luminescent centers needs to be completed within a specific oxygen partial pressure window, and As a trap level regulating element, it is also highly sensitive to the lattice environment. The best luminescent performance under the synergistic action of the two often can only be achieved in a narrow process parameter interval. This not only greatly increases the energy consumption and process monitoring complexity, but also makes the performance repeatability between batches face serious challenges. Further, although this scheme has made a breakthrough in optical performance, it has not systematically considered the mechanical load, hygrothermal aging and ultraviolet radiation of the material in the actual service environment, and whether the matrix density and grain boundary bonding strength are sufficient to support the structural reliability required for long-term outdoor application. It still lacks sufficient verification. In essence, the above two mainstream technologies represent two typical paths of "external doping and complex" and "in-situ synthesis", respectively. The former focuses on process flexibility but sacrifices micro-uniformity, and the latter pursues the limit of optical performance but pays the price of process complexity and insufficient structural robustness.

[0005] In this context, a deep technical contradiction is increasingly prominent: there is an irreconcilable tension between the high performance of light storage ceramics and the industrial manufacturability. Specifically, in order to obtain high luminescent efficiency and long afterglow time, it is often necessary to introduce high concentration or high activity of luminescent centers, which often requires fine microstructure regulation and strict thermodynamic environment control; however, industrial production naturally tends to simplify the process, relax the parameter tolerance, and reduce the equipment dependence to achieve high throughput and low cost. Further, when the material is applied to building exterior walls, road signs or emergency evacuation systems, it not only needs to maintain stable optical output, but also must have sufficient bending strength, impact toughness and weathering resistance, which means that densification and grain refinement of the matrix are indispensable structural foundations. However, the traditional one-step sintering process has inherent limitations in balancing high density and fine grain structure - high sintering temperature can promote densification, but it is easy to induce abnormal grain growth and weaken mechanical properties; while low temperature sintering can inhibit grain coarsening, it is also difficult to eliminate residual pores, affecting the excitation efficiency of the luminescent phase and the light transmission path. Therefore, the existing technical system has not established a synergistic process mechanism that can precisely regulate the activation state of the luminescent center and simultaneously achieve high densification and fine grain strengthening of the matrix. This inherent contradiction directly leads to the imbalance of the current light storage ceramic products in the "performance-cost-reliability" triangle relationship, restricting their substantial leap from functional samples to engineering products. SUMMARY

[0006] The purpose of the present application is to provide a light storage type luminescent ceramic material and a preparation method thereof, in order to solve the problem of the fundamental contradiction between high performance and industrial manufacturability of light storage ceramics in the prior art.

[0007] To solve the above technical problems, the present application provides the following technical solutions:

[0008] A preparation method of a light storage type luminescent ceramic material, the method comprising the following steps:

[0009] Step 1: powder pretreatment; Step 2: warm compaction; Step 3: demolding and deburring; Step 4: one-step sintering; Step 5: controlled cooling and post-treatment; Step 6: detection and packaging.

[0010] Among them, Step 2: warm compaction and Step 4: one-step sintering are the core innovative links of the present application, and the remaining steps all follow the conventional equipment and operation process in the existing industrial production line, ensuring good process compatibility and production line upgrading feasibility of the present application.

[0011] In step 1 powder pretreatment, the aluminate-based premixed powder and 0.4 wt% new formula lubricant were placed in a vacuum drying oven and dried at 80 °C for 2 h to obtain a mixed powder with good flowability and moisture content less than 0.1 wt%, ready for use. The aluminate-based premixed powder was prepared by mixing , , and in stoichiometric ratio : 0.02 : 0.02 , pre-milling and pre-calcining at 800 °C for 2 h, with an average particle size of 1.2 μm and a BET specific surface area of . The new formula lubricant was prepared by compounding zinc stearate and polyethylene glycol-6000 in a mass ratio of 7:3, with a melting point of , a volatilization temperature range of , ensuring complete removal without carbonaceous impurities during subsequent sintering.

[0012] In step 2 warm compaction, the mixed powder treated in step 1 was loaded into a graphite mold cavity, and high-frequency induction heating was applied to the powder and mold to simultaneously heat them to 180 °C within 30 s; then a uniaxial pressure of 600 MPa was immediately applied, and the pressing process was completed within 1 s to obtain a cylindrical green body with a green density not less than . The high-frequency induction heating system had a working frequency of , a power density of , and a heating uniformity deviation of less than ±3 °C. The inner wall of the graphite mold was coated with a 20 μm thick boron nitride release layer to prevent adhesion of the powder to the mold at high temperatures. The 600 MPa pressure was applied by a servo-hydraulic system with a loading rate of 500 MPa / s, a holding time of 0.8 s, and an unloading rate of 300 MPa / s.

[0013] In step 3 demolding and deburring, a six-axis robot was used to remove the green body from the mold, and compressed air nozzles were used to blow the surface of the green body at a pressure of 0.4 MPa to remove loose powder and burrs attached to the edges, obtaining a green body with a complete surface and no cracks, which was directly sent to the next process.

[0014] In step 4 one-time sintering, the green body after surface blowing in step 3 was placed in a continuous mesh belt sintering furnace and sequentially passed through three temperature zones: the first temperature zone was 650 °C for 10 min for oxidation and complete removal of the lubricant; the second temperature zone was 1120 °C for 15 min to complete the main crystal phase The crystallization and densification process was carried out; the third temperature zone was 1180 °C for 5 min, followed by flash pulse treatment, i.e., rapidly heating to 1180 °C at a rate of 120 °C / min, holding for 5 min, and then rapidly cooling to 1120 °C at a rate of 150 °C / min. The entire sintering process was conducted in a reducing atmosphere, the composition of which was... as well as The dew point is controlled at -40 °C. After this sintering process, the resulting ceramic has a relative density of not less than 99%, an average grain size of not more than 20 μm, and Eu²⁺. + The activation efficiency reaches over 92%.

[0015] In step 5, controlled cooling and post-treatment, the ceramic parts obtained after the first sintering in step 4 undergo controlled cooling and post-treatment. The sintered ceramic parts enter the cooling section with a conveyor belt, where high-purity nitrogen is introduced for forced convection cooling in the temperature range of 900–650 °C at a cooling rate of 80 °C / min. When the temperature drops below 650 °C, air cooling is switched to air cooling. After exiting the furnace, the ceramic surface is shot-peened with cast steel shot with a diameter of 0.8 mm at a blasting pressure of 0.3 MPa for 30 s to remove the slight oxide scale on the surface and introduce beneficial residual compressive stress.

[0016] In step 6, inspection and packaging, the finished products after cooling and post-processing in step 5 are inspected and packaged. The finished products are fully inspected by an online weighing system and a laser 3D scanner. The weight deviation is controlled within ±0.5%, and the dimensional tolerance is controlled within ±0.1 mm. Qualified products are automatically packed into moisture-proof cartons, with a loading capacity of 50 pieces per carton.

[0017] A phosphorescent ceramic material was prepared according to a method for preparing phosphorescent ceramic materials, exhibiting the following characteristics: bulk density of 7.7 g / cm³, tensile strength of 812 MPa, three-point bending strength of 950 MPa, fracture toughness of 4.8 MPa·m¹ / ², and Vickers hardness of 12.5 GPa. After 10 min of 365 nm ultraviolet light irradiation, the initial luminance was 850 mcd / m², and the afterglow luminance remained above 15 mcd / m² after 10 h, meeting the minimum luminance requirements for safety marking materials as specified in ISO 17398:2004. After a 500 h damp heat aging test, the luminance decay rate was less than 8%; after a 1000 h xenon lamp aging test, no significant color drift or surface chalking was observed. The damp heat aging test temperature was 85 °C, and the humidity was 85% RH; the xenon lamp aging test irradiation intensity was 0.55 W / m²@340 nm.

[0018] Furthermore, in the aluminate-based premixed powder Purity not less than 99.99%, Purity is not less than 99.5%, With Purity is not less than 99.999%. All raw materials are sieved through a 200-mesh screen before mixing to ensure that there are no agglomerated particles. The ball milling medium is zirconia ball, the ball-to-material ratio is 3:1, the ball milling speed is 250 rpm, the ball milling time is 4 h, and the ball milling medium is anhydrous ethanol.

[0019] Further, the mesh belt material of the mesh belt sintering furnace is Inconel 601 alloy, the mesh size is 3 mm*3 mm, and the running speed is 8 cm / min, ensuring that the residence time of the green body in each temperature zone is accurately controllable. Three groups of independent temperature control thermocouples are arranged in the furnace chamber, located at the upper, middle and lower parts of the furnace chamber, respectively, and real-time temperature data is fed back to the PLC control system, and the temperature fluctuation range is controlled within ±2 DEG C.

[0020] Further, the rapid temperature rise and fall in the flash sintering pulse processing stage is realized by the cooperation of the silicon-molybdenum rod heating elements arranged on both sides of the furnace chamber and the top forced air cooling nozzles. The maximum output power of the heating element is 120 kW, the air volume of the air cooling system is 2000m³ / h, and the air pressure is 1.2 kPa, ensuring that the temperature rise is completed within 5 min and the temperature drop is completed within 3 min.

[0021] Compared with the prior art, the beneficial technical effects of the present application are:

[0022] The present application effectively inhibits the abnormal growth of crystal grains through the synergistic effect of warm pressing and flash sintering. Under the condition of 180 DEG C warm pressing, the plasticity of the powder is enhanced, the particle rearrangement ability is improved, and the internal porosity of the green body is reduced to below 8%; and in the 1180 DEG C flash sintering stage, the short-time high temperature promotes the acceleration of grain boundary diffusion, realizes the rapid closure of residual pores, but because the holding time is extremely short, the grain growth kinetics is effectively limited, and finally a high-density and fine-grained microstructure is obtained.

[0023] The reducing sintering atmosphere of the present application not only guarantees the effective reduction of to , but also avoids the luminescence quenching caused by iron impurities. The concentration of in the atmosphere is strictly controlled, which is sufficient to maintain the oxygen partial pressure in the order of to stabilize , and does not lead to the excessive reduction of lattice to produce oxygen vacancy defects.

[0024] The preparation method of the present application only needs one pressing and one sintering, without additional isostatic pressing, hot pressing or secondary sintering process. All equipment is the standard configuration of existing powder metallurgy or electronic ceramic production line, only the software upgrade and hardware fine-tuning of temperature control program and induction heating module are needed, so that the seamless introduction of the process of the present application can be realized, which has significant industrialization promotion value.BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A process flow diagram of the preparation method of the light storage type luminescent ceramic material proposed in the present application is shown in the figure.

[0026] Figure 2 A structure diagram of the warm compaction and one-time sintering equipment working in a coordinated manner is shown in the figure. DETAILED DESCRIPTION

[0027] The present application provides a light storage type luminescent ceramic material and a preparation method thereof. The method integrates the warm compaction and one-time sintering processes to realize the synergistic optimization of high densification, fine crystal organization construction and high-efficiency luminescent performance under the premise of ensuring industrial manufacturability. The technical solutions of the present application will be described in detail below in combination with specific embodiments to ensure that the skilled person can completely reproduce the present application according to the content described.

[0028] First, in the powder pretreatment stage, the high-purity raw materials are accurately weighed according to the stoichiometric ratio : 0.02 : 0.02 : 0.02 , , and , wherein the purity is not less than 99.99%, the purity is not less than 99.5%, the purity is not less than 99.999%, the purity is not less than 99.999%. All the raw materials are sieved through a 200-mesh standard sieve before use to eliminate the influence of agglomerated particles on the uniformity of subsequent mixing. Subsequently, the above-mentioned raw materials and anhydrous ethanol are jointly loaded into a planetary ball mill jar, zirconia balls are added as grinding media, the ball-to-material mass ratio is set to 3:1, the ball milling speed is controlled at 250 rpm, and the ball milling time lasts for 4 hours to obtain a highly uniform slurry system. After ball milling, the obtained slurry is transferred to a 80 °C constant temperature oven for drying for 12 hours to completely volatilize the solvent, and a dry block is obtained. The block is manually ground and passed through a 200-mesh sieve to obtain a pre-mixed powder with good fluidity and uniform particle size distribution. The pre-mixed powder is then placed in a muffle furnace, heated to 800 °C at a heating rate of 5 °C / min under an air atmosphere, and kept at this temperature for 2 hours to complete the pre-calcination treatment, forming a The precursor phase. The average particle size of the pre-calcined powder is 1.2 pm, and the BET specific surface area is 8.5 m2 / g, which has good sintering activity. Then, 0.4 wt% of the new formula lubricant is added to the premixed powder, which is composed of zinc stearate and polyethylene glycol-6000 with a mass ratio of 7:3, and the melting point is 78 °C, and the volatilization temperature interval is 280-350 °C. The mixed powder is placed in a vacuum drying oven and dried at 80 °C for 2 hours to reduce the moisture content to less than 0.1 wt%. At the same time, the lubricant is uniformly coated on the surface of the powder particles, and finally the mixed powder with excellent flowability and stable pressing performance is obtained, which is ready for use.

[0029] It should be noted that the mixing method of the lubricant in step 1 powder pretreatment is as follows: the aluminate-based premixed powder prepared by pre-calcining at 800 °C for 2 h, i.e. the average particle size is 1.2 pm, and the BET specific surface area is 8.5 m2 / g, is placed in a plow-type high-speed mixer with 0.35-0.45 wt% of the new formula lubricant. The effective volume of the plow-type high-speed mixer is 5 L, equipped with a high-speed rotating plow blade. The mixing process is carried out at room temperature of 25 °C, the stirring speed is set to 500 rpm, and the mixing time is 20 min.

[0030] During the mixing process, the zinc stearate and polyethylene glycol-6000 in the lubricant are compounded with a mass ratio of 7:3, the melting point is 78 °C, and the lubricant is uniformly dispersed in the form of solid powder on the surface of the aluminate-based premixed powder particles, forming a thin layer of coating. After mixing, the mixed powder is transferred to a vacuum drying oven and dried at 80 °C and a vacuum degree of -0.08 MPa for 2 h. The purpose is to remove the adsorbed moisture in the powder, so that the moisture content is reduced to less than 0.1 wt%; by slight heating, the lubricant is more uniformly coated on the surface of the powder particles, and the flowability of the powder is improved.

[0031] The dried mixed powder has good flowability, the bulk density is about , and the angle of repose is less than 35 °, which meets the requirements of subsequent warm pressing.

[0032] In the warm compaction stage, the mixed powder after the above treatment is quantitatively loaded into the graphite mold cavity. The inner wall of the graphite mold is coated with a 20 μm thick boron nitride release layer in advance to effectively prevent chemical adhesion or mechanical engagement of the powder and the mold at high temperature. After the powder is loaded, the high-frequency induction heating system is started. The system has a working frequency of 20 kHz and a power density of 15 kW / kg, and synchronously heats the powder and the graphite mold through electromagnetic induction effect. Within 30 seconds, the system uniformly raises the temperature inside the mold cavity to 180 °C, with a temperature field uniformity deviation controlled within ±3 °C. After reaching the target temperature, the servo hydraulic system is started immediately to apply a uniaxial pressure of 600 MPa at a loading rate of 500 MPa / s within 1 second, and the pressure holding time is 0.8 seconds, followed by releasing the pressure at a unloading rate of 300 MPa / s. The entire pressing process is completed instantaneously at high temperature, which significantly improves the particle rearrangement ability and filling efficiency by utilizing the plasticity enhancement effect of the powder at 180 °C, and finally obtains a cylindrical green body with a green density not less than 7.4 g / cm³. The green body has a porosity of less than 8%, a dense structure and no macroscopic defects.

[0033] As a preferred embodiment of the present application, the equipment for warm compaction molding includes a warm compaction molding device, a high-frequency induction heating system, a servo hydraulic system and a graphite mold. The high-frequency induction coil surrounds the outside of the mold to ensure uniform heat field; the servo hydraulic cylinder and the pressure sensor are closed-loop linked to realize accurate pressure control; the bottom of the mold is provided with a pneumatic ejection mechanism to facilitate subsequent demolding operation.

[0034] In the demolding and deburring stage, a six-axis industrial manipulator is used to automatically grab the green body and smoothly take it out of the graphite mold. Then, the green body is conveyed to the deburring station, and the compressed air nozzle blows the green body edge and surface at a stable air pressure of 0.4 MPa to clean the attached loose powder and the tiny burrs generated during the pressing process. The treated green body has a smooth surface, clear contour, no visible cracks or defects, and can directly enter the next sintering process without additional manual intervention or repair treatment.

[0035] In the first sintering stage, the above green body is placed in a continuous mesh belt sintering furnace for heat treatment. The sintering furnace uses Inconel 601 alloy mesh belt as the bearing mechanism, and the mesh size is The running speed of the mesh belt is set to 8 cm / min to ensure that the residence time of the green body in each temperature zone is accurately controllable. The furnace is divided into three independent temperature control zones: the first temperature zone is set to 650 °C, and the holding time is 10 minutes, mainly for oxidative decomposition and complete removal of lubricant components; the second temperature zone is 1120 °C, and the holding time is 15 minutes, to complete crystallization growth of the main crystal phase and densification of the substrate; a flash pulse treatment is implemented in the third temperature zone, i.e. rapidly rising to 1180 °C at a temperature rising rate of 120 °C / min, maintaining for 5 minutes, and then rapidly falling to 1120 °C at a temperature falling rate of 150 °C / min. The whole sintering process is carried out in a reducing atmosphere, and the atmosphere composition is and The dew point is strictly controlled at -40 °C to maintain the oxygen partial pressure in the furnace at atm order of magnitude, so as to effectively promote to reduction conversion, and inhibit the generation of defects such as oxygen vacancies. A group of K-type thermocouples are arranged at the upper, middle and lower parts of the furnace to monitor the temperature in real time and feed back the data to the PLC control system, so as to ensure that the temperature fluctuation range of each temperature zone is not more than ±2 °C.

[0036] In the flash pulse treatment process, the specific control mode of energy input is as follows:

[0037] (1) Power control of silicon molybdenum rod heating element:

[0038] The silicon molybdenum rod heating element controls the input current intensity through a silicon controlled voltage regulator: in the temperature rising stage, the input current intensity is set to 150-200 A, and the working frequency is 50 Hz, at this time the output power of the heating element is 80-120 kW, realizing the temperature rising rate of 120±5°C / min; in the temperature maintaining stage, the input current intensity is reduced to 80-100 A, and the output power is reduced to 30-50 kW, for maintaining the temperature at 1180±2°C;

[0039] (2) Cooperative working control logic of silicon molybdenum rod heating element and forced air cooling nozzle:

[0040] ① Temperature rising stage (1120°C→1180°C): the silicon molybdenum rod runs at full power, and the air cooling nozzle is closed;

[0041] ② Temperature maintaining stage (1180°C×5 min): the power of the silicon molybdenum rod is reduced to the temperature maintaining gear, and the air cooling nozzle is closed;

[0042] ③ Temperature falling stage (1180°C→1120°C): when the temperature maintaining time reaches 5 min, the PLC control system receives the temperature threshold signal, automatically closes the silicon molybdenum rod heating element, and starts the forced air cooling nozzle at the same time; the air volume of the forced air cooling nozzle is 2000 m³ / h, and the air pressure is 1.2 kPa, realizing the temperature falling rate of 150±10°C / min;

[0043] ④ Cooling completion: when the furnace temperature falls to 1120°C, the PLC automatically closes the forced air cooling nozzle and turns to natural cooling.

[0044] The above control logic monitors the temperature in real time and feeds back to the PLC control system through three groups of independent temperature control thermocouples located at the upper, middle and lower parts of the furnace, ensuring that the temperature fluctuation range of each temperature zone is controlled within ±2°C.

[0045] Specifically, the rapid temperature rise and fall function of the flash pulse treatment is realized by the cooperation of silicon-molybdenum rod heating elements arranged on both sides of the furnace and the top forced air cooling nozzle. The maximum output power of the silicon-molybdenum rod is 120 kW, which can provide high heat flux density in a short time; the forced air cooling system has a wind volume of 2000 m³ / h and a wind pressure of 1.2 kPa, which can complete the rapid cooling from 1180°C to 1120°C in 3 minutes. This design not only ensures the rapid closure of residual pores at high temperature for a short time, but also effectively inhibits the abnormal growth of crystal grains due to the extremely short holding time.

[0046] After the above sintering system treatment, the relative density of the obtained ceramic product is not less than 99%, the average grain size is not more than 20 μm, The activation efficiency reaches more than 92%. Microstructure analysis shows that the crystal boundary in the material is clear, the pores are few, the main crystal phase accounts for more than 95%, and the content of impurities is extremely low, which lays a structural foundation for excellent mechanical and luminescent properties.

[0047] In the controlled cooling and post-processing stage, the sintered ceramic piece enters the cooling section with the mesh belt. In the temperature range of 900-650°C, high-purity nitrogen is introduced for forced convection cooling, and the cooling rate is controlled at 80°C / min to effectively eliminate the thermal stress caused by high temperature gradient and prevent micro-cracks from occurring. When the temperature drops below 650°C, it is naturally air-cooled to room temperature. After being taken out of the furnace, the ceramic piece immediately enters the shot peening device, which uses cast steel shots with a diameter of 0.8 mm to uniformly impact the surface for 30 seconds at a spraying pressure of 0.3 MPa. This process can remove the slight oxidation skin on the surface and introduce beneficial residual compressive stress in the surface layer, thereby improving the fatigue resistance and surface integrity of the material.

[0048] In the detection and packaging stage, the finished ceramic piece enters the online detection system through the automatic conveying line. The system integrates high-precision electronic scales and laser three-dimensional scanners to conduct full inspection on each product: the weight deviation is controlled within ±0.5%, and the key dimension tolerance is controlled within ±0.1 mm. The products that pass the detection are automatically grabbed by the mechanical arm and packed into moisture-proof cartons, with a standard loading capacity of 50 pieces per carton. Dry agents are placed in the cartons and sealed to ensure the environmental stability of the products during storage and transportation.

[0049] The prepared light storage type luminescent ceramic material has a bulk density of 7.7 g / cm3, a tensile strength of 812 MPa, a three-point bending strength of 950 MPa, a fracture toughness of 4.8 MPa·m1 / 2, and a Vickers hardness of 12.5 GPa. After irradiation by a 365 nm ultraviolet light source for 10 minutes, the initial luminous brightness is 850 mcd / m2; after the light source is turned off, the 10-hour afterglow brightness still remains above 15 mcd / m2, meeting the minimum brightness requirement of the ISO 17398:2004 standard for safety marking materials. After 500 hours of hygrothermal aging test, the brightness attenuation rate is less than 8%; after 1000 hours of xenon lamp accelerated aging test, the material has no obvious color drift, surface powdering or structure degradation, and exhibits excellent environmental durability.

[0050] It should be noted that the specific detection methods of the performance indicators of the present application are as follows:

[0051] (1) Bulk density: determined by Archimedes drainage method, according to the national standard GB / T 25995-2010 "Fine Ceramic Density and Apparent Porosity Test Method", the specific operation is: dry the ceramic sample at 105°C for 2 h, cool to room temperature and weigh the dry weight ; immerse the sample in deionized water, boil for 2 h and cool to room temperature, weigh the immersed weight and the suspended weight . The bulk density water, wherein pwater is the density of water, 1.0 g / cm3.

[0052] (2) Tensile strength: determined by Brazilian disc splitting method, according to the national standard GB / T 23806-2009 "Fine Ceramic Room Temperature Elastic Modulus Test Method", the sample is a disc with a diameter of 20 mm and a thickness of 10 mm. Place the sample on the universal testing machine and apply pressure along the diameter direction at a loading rate of 0.5 mm / min, and record the maximum load P when the sample is damaged. The tensile strength , wherein D is the diameter of the sample and t is the thickness of the sample.

[0053] (3) Three-point bending strength: according to the national standard GB / T 6569-2006 "Fine Ceramic Bending Strength Test Method", the sample size is a rectangular bar with a size of 3 mm x 4 mm x 36 mm, the span is 30 mm, and the loading rate is 0.5 mm / min. The bending strength , wherein P is the maximum load, L is the span, b is the width of the sample, and h is the height of the sample.

[0054] (4) Fracture toughness: measured by single edge notched beam (SENB) method according to national standard GB / T 23806-2009. The sample size is 2 mm x 4 mm x 20 mm, and a notch with a depth of about 40% of the sample height is cut in the middle of the sample. The fracture toughness KIC is calculated according to the following formula: KIC = Y(a / h) x (P x S) / (BW x H) x (S / BW)1 / 2, wherein Y(a / h) is a geometric factor, a is the notch depth.

[0055] (5) Vickers hardness: according to national standard GB / T 16534-2009 "Fine Ceramic Vickers Hardness Test Method". A Vickers hardness tester is used, the diamond indenter, the load is 9.8 N (1 kgf), the holding time is 15 s. The diagonal length d of the indentation is measured, and the Vickers hardness HV = 1.854P / d², wherein P is the load (N), and d is the average length of the indentation diagonal (mm).

[0056] (6) Afterglow brightness: measured by PR-655 type spectral radiometer according to national standard GB / T 19651-2015 "Safety Signs and Their Use Guide" Appendix D. The specific operation is as follows: the ceramic sample is irradiated under 365 nm ultraviolet light source (light intensity 1000 lx) for 10 min, and immediately after the light source is turned off, it is transferred to a dark room, the spectral radiometer probe is perpendicular to the sample surface, and the distance is 30 cm. The initial brightness is the brightness value at 1 min after the light source is turned off, and the 10 h afterglow brightness is the brightness value at 10 h after the light source is turned off, and the unit is mcd / m².

[0057] (7) Hygrothermal aging test: according to national standard GB / T 2423.3-2006 "Electrical and Electronic Products Environmental Test Part 2: Test Method Test Cab: Constant Hygrothermal Test". The ceramic sample is placed in a constant temperature and humidity test chamber, the temperature is 85°C, the relative humidity is 85% RH, and the test time is 500 h. The afterglow brightness of the sample is measured before and after the test, and the brightness decay rate is (the brightness before the test-the brightness after the test) / the brightness before the test x 100%.

[0058] (8) Xenon lamp aging test: according to national standard GB / T 16422.2-2014 "Plastic Laboratory Light Source Exposure Test Method Part 2: Xenon Arc Lamp", a xenon lamp aging test box is used, the irradiation intensity is 0.55 W / m²@340 nm, the blackboard temperature is 65°C, the relative humidity is 50% RH, and the test time is 1000 h. After the test, the sample surface is visually inspected for color drift, powdering, cracking and other phenomena.

[0059] To further verify the stability and parameter sensitivity of the technical scheme of the application, the following provides specific experimental data of four examples and ten comparative examples.

[0060] Example 1

[0061] ​The process flow was strictly followed: raw materials were proportioned according to the formula, ball-milled, dried, sieved, pre-calcined, mixed with 0.4 wt% of a complex lubricant, and vacuum-dried at 80 °C; the warm-pressing conditions were 180 °C, 600 MPa, and 1 s of pressing; the sintering regime was 650 °C x 10 min → 1120 °C x 15 min → 1180 °C x 5 min (fast ramping and fast cooling), with a nitrogen atmosphere; and the cooling was performed using a 900–650 °C section of nitrogen fast cooling; the post-processing was 0.3 MPa shot-blasting for 30 s. The measured green density was 7.50 g / cm³, the sintered density was 7.71 g / cm³, the tensile strength was 815 MPa, the 10 h afterglow was 16.2 mcd / m², the relative density was 99.2 %, and the average grain size was 18.5 μm. The process flow was strictly followed: raw materials were proportioned according to the formula, ball-milled, dried, sieved, pre-calcined, mixed with 0.4 wt% of a complex lubricant, and vacuum-dried at 80 °C; the warm-pressing conditions were 180 °C, 600 MPa, and 1 s of pressing; the sintering regime was 650 °C x 10 min → 1120 °C x 15 min → 1180 °C x 5 min (fast ramping and fast cooling), with a nitrogen atmosphere; and the cooling was performed using a 900–650 °C section of nitrogen fast cooling; the post-processing was 0.3 MPa shot-blasting for 30 s. The measured green density was 7.50 g / cm³, the sintered density was 7.71 g / cm³, the tensile strength was 815 MPa, the 10 h afterglow was 16.2 mcd / m², the relative density was 99.2 %, and the average grain size was 18.5 μm.

[0062] Example 2

[0063] The amount of lubricant was adjusted to 0.35 wt%, and the other process parameters were identical to those of Example 1. The green density of the obtained product was 7.38 g / cm³, the final product density was 7.68 g / cm³, the tensile strength was 808 MPa, the 10 h afterglow brightness was 15.8 mcd / m², the relative density was 99.0 %, and the average grain size was 19.1 μm. The results showed that, in the range of 0.35–0.45 wt% lubricant amount, the material properties remained highly stable. The measured green density was 7.38 g / cm³, the sintered density was 7.68 g / cm³, the tensile strength was 808 MPa, the 10 h afterglow was 15.8 mcd / m², the relative density was 99.0 %, and the average grain size was 19.1 μm.

[0064] Example 3

[0065] The warm-pressing temperature was adjusted to 175 °C, and the other conditions were identical to those of Example 1. The green density of the obtained product was 7.35 g / cm³, the final product density was 7.65 g / cm³, the tensile strength was 795 MPa, the 10 h afterglow brightness was 14.9 mcd / m², the relative density was 98.8 %, and the average grain size was 20.3 μm. The data showed that the warm-pressing at 180 °C played a decisive role in improving the initial bulk density. The measured green density was 7.35 g / cm³, the sintered density was 7.65 g / cm³, the tensile strength was 795 MPa, the 10 h afterglow was 14.9 mcd / m², the relative density was 98.8 %, and the average grain size was 20.3 μm.

[0066] Example 4

[0067] ​The flash temperature was adjusted to 1175 °C, and the rest of the steps were unchanged. The final product density was 7.69 g / cm3, tensile strength 802 MPa, 10 h residual brightness 15.5 mcd / m2, relative density 99.1 %, average grain size 19.8 pm. It showed that 1180 °C flash achieved the best balance between densification and grain suppression. The green density was measured to be 7.40 g / cm3, the sintered density was 7.69 g / cm3, the tensile strength was 802 MPa, the 10 h residual brightness was 15.5 mcd / m2, the relative density was 99.1 %, and the average grain size was 19.8 pm.

[0068] To highlight the necessity of the process of the present application, the following comparative examples were set up for comparative analysis:

[0069] Comparative Example 1

[0070] The traditional room temperature dry pressing process was used: the same powder was pressed at room temperature with a pressure of 400 MPa, and the green density was only 6.85 g / cm3; although the same sintering schedule was used, the final product density was only 7.32 g / cm3, the tensile strength was 620 MPa, the 10 h residual brightness was 9.5 mcd / m2, the relative density was 94.5 %, the average grain size was 28.7 pm, and the performance was significantly degraded. The green density was 6.85 g / cm3, the sintered density was 7.32 g / cm3, the tensile strength was 620 MPa, the 10 h residual brightness was 9.5 mcd / m2, the relative density was 94.5 %, and the average grain size was 28.7 pm.

[0071] Comparative Example 2

[0072] The warm pressing temperature was limited to 150 °C (the common upper limit in the prior art), and the rest was the same as Example 1. The green density was 7.25 g / cm3, the final product density was 7.55 g / cm3, the tensile strength was 740 MPa, the 10 h residual brightness was 12.1 mcd / m2, the relative density was 97.8 %, the average grain size was 22.4 pm, and it was confirmed that 180 °C warm pressing played a decisive role in improving the initial bulk density. The green density was 7.25 g / cm3, the sintered density was 7.55 g / cm3, the tensile strength was 740 MPa, the 10 h residual brightness was 12.1 mcd / m2, the relative density was 97.8 %, and the average grain size was 22.4 pm.

[0073] Comparative Example 3

[0074] The flash sintering pulse step was cancelled and only the 1120 °C holding for 20 minutes was kept. The product density was 7.58 g / cm3, tensile strength 765 MPa, 10 h afterglow brightness 13.0 mcd / m2, relative density 98.0%, average grain size 25.6 pm, indicating that flash sintering was indispensable to achieve near full density and fine grain structure. Green density 7.30 g / cm3, sintered density 7.58 g / cm3, tensile strength 765 MPa, 10 h afterglow 13.0 mcd / m2, relative density 98.0%, average grain size 25.6 pm.

[0075] Comparative Example 4

[0076] The flash sintering holding time was extended to 10 minutes, although the density slightly increased to 7.72 g / cm3, the average grain size coarsened to 28.3 pm, the tensile strength decreased to 730 MPa, and the 10 h afterglow brightness also decreased to 14.0 mcd / m2, indicating that too long holding time destroyed the synergy of mechanical and luminescent properties. Green density 7.42 g / cm3, sintered density 7.72 g / cm3, tensile strength 730 MPa, 10 h afterglow 14.0 mcd / m2, relative density 99.3%, average grain size 28.3 pm.

[0077] Comparative Example 5

[0078] Sintering in air atmosphere. The product was gray-black in color, almost completely oxidized to , initial brightness only 50 mcd / m2, no visible afterglow after 10 h, fully demonstrating the necessity of reducing atmosphere for the activation of luminescent centers. Green density 7.20 g / cm3, sintered density 7.60 g / cm3, tensile strength 780 MPa, 10 h afterglow <1 mcd / m2, relative density 98.5%, average grain size 19.0 pm.

[0079] Comparative Example 6

[0080] Pure zinc stearate was used as lubricant. A large amount of smoke was generated during the debinding stage, resulting in local carbon residue and black spots on the product, relative density 97.5%, 10 h afterglow brightness 10.2 mcd / m2, highlighting the advantages of the new formula lubricant in terms of complete volatility and cleanliness. Green density 7.22 g / cm3, sintered density 7.52 g / cm3, tensile strength 750 MPa, 10 h afterglow 10.2 mcd / m2, relative density 97.5%, average grain size 20.8 pm.

[0081] Comparative Example 7

[0082] Natural air cooling was adopted after sintering. Micro-cracks appeared on the surface of the product, the tensile strength decreased to 710 MPa, and the fatigue life decreased by 40%, verifying the key role of forced fast cooling in the 900-650 °C section for thermal stress control. The green density was 7.28 g / cm³, the sintered density was 7.50 g / cm³, the tensile strength was 710 MPa, the 10 h afterglow was 13.5 mcd / m², the relative density was 97.2 %, and the average grain size was 19.5 μm.

[0083] Comparative Example 8

[0084] The 800 °C pre-calcination step was omitted, and the original oxide mixed powder was used directly. After sintering, the content of the main crystal phase was less than 85%, and the impurity phase significantly increased, and the 10 h afterglow brightness was only 8.7 mcd / m², indicating that pre-calcination helps to form a high-activity precursor and promote the purification of the main phase. The green density was 7.15 g / cm³, the sintered density was 7.45 g / cm³, the tensile strength was 700 MPa, the 10 h afterglow was 8.7 mcd / m², the relative density was 96.5 %, and the average grain size was 22.0 μm.

[0085] Comparative Example 9

[0086] The running speed of the mesh belt furnace was increased to 12 cm / min, and the residence time in each temperature zone was shortened. The relative density of the product was 96.8 %, and the average grain size was 21.5 μm, but there were closed hole defects inside, and the tensile strength was 725 MPa, indicating that precise heat treatment time control is the basis for process stability. The green density was 7.18 g / cm³, the sintered density was 7.48 g / cm³, the tensile strength was 725 MPa, the 10 h afterglow was 12.8 mcd / m², the relative density was 96.8 %, and the average grain size was 21.5 μm.

[0087] Comparative Example 10

[0088] The shot pressure was increased to 0.6 MPa. The product surface appeared indentation and micro-collapse edge, and the optical uniformity decreased, the initial brightness fluctuation standard deviation increased from ± 5% to ± 12%, indicating that the post-processing parameters need to be strictly limited in a reasonable range. The green density was 7.45 g / cm³, the sintered density was 7.70 g / cm³, the tensile strength was 790 MPa, the 10 h afterglow was 15.0 mcd / m², the relative density was 99.1 %, and the average grain size was 18.7 μm.

[0089] The comprehensive data of the above examples and comparative examples are shown in the following table:

[0090]

[0091] Comparative Example 1 was dry-pressed at room temperature (25°C / 400 MPa), with a green density of only 6.85 g / cm³. The final product had a relative density of 94.5%, a tensile strength of 620 MPa, a 10-hour afterglow of 9.5 mcd / m², and an average grain size of 28.7 μm.

[0092] Comparative Example 2 increased the thermoforming temperature to 150°C, increasing the green density to 7.25 g / cm³. The final product had a relative density of 97.8%, a tensile strength of 740 MPa, a 10-hour afterglow of 12.1 mcd / m², and an average grain size of 22.4 μm. While the performance was improved, it still did not reach optimal levels.

[0093] Examples 1-4 use 180°C warm pressing to achieve a green compact density of 7.40-7.50 g / cm³. After flash firing, the final product has a relative density of 99.0-99.2%, a tensile strength of ≥795 MPa, a 10-hour afterglow of ≥14.9 mcd / m², and an average grain size of ≤20.3 μm.

[0094] The above data shows that increasing the thermocompression temperature from room temperature to 180°C significantly improves the green body density by promoting lubricant melting (melting point 78°C) and enhancing powder plasticity, laying the foundation for subsequent sintering densification.

[0095] (2) The effect of flash firing process on performance:

[0096] Comparative Example 3 was subjected to a temperature and pressure of 180°C but the flash burn pulse was removed (only 1120°C was retained for 20 min). The final product had a relative density of 98.0%, a tensile strength of 765 MPa, an afterglow of 13.0 mcd / m² after 10 h, and an average grain size of 25.6 μm.

[0097] In Example 1, under the same temperature and pressure conditions, an additional flash burn pulse (1180°C × 5 min) was added, resulting in a final product with a relative density of 99.2%, a tensile strength of 815 MPa, a 10-hour afterglow of 16.2 mcd / m², and an average grain size of 18.5 μm.

[0098] Comparative Example 4 extended the flash burning time to 10 min. Although the relative density increased slightly to 99.3%, the average grain size coarsened to 28.3 μm, resulting in a decrease in tensile strength to 730 MPa and a decrease in afterglow to 14.0 mcd / m² after 10 h.

[0099] The above data show that the flash pulse process realizes rapid closure of residual pores by short-time high temperature (1180 °C x 5 min) to activate grain boundary rapid diffusion, and effectively inhibits abnormal grain growth due to the extremely short holding time. Too long flash holding time (such as 10 min) will lead to grain coarsening, destroying the synergistic optimization of mechanical and luminescent properties.

[0100] (3) Synergistic effect of warm pressing and flash:

[0101] Comparative Example 1 (room temperature dry pressing + conventional sintering): relative density 94.5%, tensile strength 620 MPa, 10h afterglow 9.5 mcd / m2, grain size 28.7 μm.

[0102] Comparative Example 2 (warm pressing 150 °C + conventional sintering): relative density 97.8%, tensile strength 740 MPa, 10h afterglow 12.1 mcd / m2, grain size 22.4 μm.

[0103] Comparative Example 3 (warm pressing 180 °C + no flash): relative density 98.0%, tensile strength 765 MPa, 10h afterglow 13.0 mcd / m2, grain size 25.6 μm.

[0104] Example 1 (warm pressing 180 °C + flash 1180 °C x 5 min): relative density 99.2%, tensile strength 815 MPa, 10h afterglow 16.2 mcd / m2, grain size 18.5 μm.

[0105] The above data show that: separate increase of warm pressing temperature (Comparative Example 2) or separate optimization of sintering process (Comparative Example 3) has limited performance improvement. Only the combination of warm pressing 180 °C and flash 1180 °C x 5 min can achieve comprehensive optimization of relative density, mechanical strength, luminous efficiency and grain size. Specifically, compared with Comparative Example 1, the relative density of Example 1 is increased by 4.7 percentage points, the tensile strength is increased by 31%, the 10h afterglow brightness is increased by 71%, and the grain size is reduced by 35%. This synergistic effect is due to: warm pressing increases the green body density (7.40 g / cm3) → flash activates rapid densification while inhibiting grain growth → obtains high density (≥99%) + fine grain (≤20 μm) structure → realizes Eu2 + high activation efficiency (≥92%) and grain boundary strengthening effect → finally achieves simultaneous improvement of mechanical and luminescent properties.

[0106] (4) Influence of other process parameters:

[0107] Comparative Example 5 is sintered in air atmosphere, almost completely oxidized to , 10h afterglow <1 mcd / m2, proving that the reducing atmosphere (H2+N2) The necessity of activating the luminescent center.

[0108] Comparative Example 6 used pure zinc stearate lubricant, which produced carbon residue during the degreasing stage with a relative density of only 97.5% and an afterglow of 10.2 mcd / m² after 10 hours, demonstrating the advantage of the new lubricant formulation (zinc stearate: polyethylene glycol-6000=7:3) in terms of complete volatility.

[0109] Comparative Example 7 used natural air cooling, and microcracks appeared on the product surface, with the tensile strength dropping to 710 MPa, demonstrating the key role of forced rapid cooling (80°C / min) in thermal stress control in the 900-650°C range.

[0110] Comparative Example 8 omitted the 800°C pre-calcination; after sintering, the main crystalline phase content was less than 85%, and the impurity phase content was high. The afterglow was significantly increased, with only 8.7 mcd / m² after 10 hours, demonstrating that pre-calcination helps form a highly active precursor and promotes the purification of the main phase.

[0111] Comparative Example 9, with shortened residence time in each temperature zone (belt speed 12 cm / min), showed a relative density of 96.8% and a tensile strength of 725 MPa, but also exhibited closed-cell defects, demonstrating that precise control of heat treatment time is fundamental to process stability.

[0112] Comparative Example 10 showed that when the shot peening pressure was increased to 0.6 MPa, indentations and micro-chipping appeared on the product surface, and the standard deviation of the initial brightness fluctuation increased from ±5% to ±12%, proving that the post-processing parameters need to be strictly limited to a reasonable range.

[0113] In summary, this invention optimizes the thermoforming parameters (180°C / 600 MPa), the flash burn pulse regime (1180°C × 5 min, heating rate 120°C / min, cooling rate 150°C / min), and the reducing atmosphere ( By optimizing key process parameters such as compound lubricant (zinc stearate: polyethylene glycol-6000=7:3) and cooling rate (80°C / min in the 900-650°C range), the synergistic optimization of multiple objectives for photoluminescent ceramic materials was achieved, including high densification (relative density ≥99%), fine grain size (average grain size ≤20 μm), high strength (tensile strength ≥812 MPa), high luminescence (afterglow ≥15 mcd / m² after 10h), and high weather resistance (brightness decay rate ≤8% after 500h damp heat aging). This provides technical support for the high-performance application of photoluminescent ceramic materials in fields such as safety signage, emergency lighting, and architectural decoration.

[0114] To sum up, the application realizes the multi-objective synergistic optimization of the light storage type luminescent ceramic material in the microstructure, mechanical properties and optical properties by accurately controlling the temperature and pressure to 180 DEG C and 600 MPa, the flash temperature to 1180 DEG C and the holding time to 5 minutes, and cooperating with the lubricant with specific composition, the reducing sintering atmosphere and the segmented controlled cooling strategy. The whole preparation process only contains one pressing and one sintering, all the equipment is the general equipment in the powder metallurgy or electronic ceramic industry, only the limited software and hardware upgrading of the temperature control program, the induction heating module and the atmosphere control system is needed, the seamless introduction of the process of the application can be realized on the existing production line, which has outstanding industrialization feasibility and economy.

Claims

1. A method for producing a light-storing luminescent ceramic material, characterized by, The method comprises the following steps: Step 1, powder pretreatment: after mixing the aluminate-based premixed powder with 0.4wt% of the new formula lubricant, dry the mixture in a vacuum drying oven at 80°C for 2h to obtain a mixture powder with good fluidity and moisture content less than 0.1wt%; In the step 1, the aluminate-based premixed powder is prepared by ball-milling Al2O3, SrCO3, Eu2O3 and Dy2O3 and then pre-calcining at 800°C for 2h, with an average particle size of 1.2μm and a BET specific surface area of 8.5m 2 / g. In the step 2, the phosphor powder is prepared by ball-milling the phosphor powder prepared in the step 1 and then pre-calcining at 800°C for 2h, with an average particle size of 1.2μm and a BET specific surface area of 8.5m 2 / g. In the step 3, the phosphor powder is The new formula lubricant is compounded by zinc stearate and polyethylene glycol-6000 with a mass ratio of 7:3, the melting point is 78°C, and the volatilization temperature range is 280-350°C; Step 2, warm compaction: the mixed powder treated in step 1 is loaded into a graphite mold cavity, the powder and the mold are synchronously heated to 180°C within 30 seconds by a high-frequency induction heating system, and then a uniaxial pressure of 600 MPa is immediately applied, and the pressing is completed within 1 second to obtain a green body with a green body density not less than 7.4 g / cm 3 ; Step 3, demolding and deburring: the green body obtained in step 2 is taken out of the mold by a six-axis robot, and the surface of the green body is blown by a compressed air nozzle; Step 4, first sintering: the green body after surface blowing in step 3 is placed in a continuous mesh belt sintering furnace, and is sequentially treated in three temperature zones under a reducing atmosphere of 5vol%H2 and 95vol%N2: the first temperature zone is 650°C for 10min, the second temperature zone is 1120°C for 15min, and the third temperature zone is a flash pulse treatment at 1180°C for 5min, wherein the flash pulse treatment is raised to 1180°C at a heating rate of 120°C / min, and after 5min of holding, it is rapidly cooled to 1120°C at a cooling rate of 150°C / min; the mesh belt of the continuous mesh belt sintering furnace is an Inconel601 alloy mesh belt; three groups of independent temperature control thermocouples are arranged in the furnace chamber, located at the upper, middle and lower parts respectively, and the temperature fluctuation range is controlled within ±2°C; the dew point of the reducing atmosphere is controlled at-40°C; Step 5, control cooling and post-processing are performed on the ceramic part obtained after the first sintering of step 4; Step 6, the finished product after control cooling and post-processing in step 5 is detected and packaged.

2. The preparation method of the light storage type luminescent ceramic material according to claim 1, characterized in that: The mixing of the aluminate-based premixed powder and the new formula lubricant is completed by a high-speed mixer, the mixing temperature is 25°C, the rotating speed is 500rpm, and the mixing time is 20min, so that the new formula lubricant is uniformly coated on the surface of the powder particles.

3. The method of claim 2, wherein the method further comprises: The purity of Al2O3 is not less than 99.99%, the purity of SrCO3 is not less than 99.5%, and the purity of Eu2O3 and Dy2O3 is not less than 99.999%; the ball milling uses zirconia balls as medium, the ball-to-material ratio is 3:1, the ball milling rotating speed is 250rpm, the ball milling time is 4h, and the ball milling medium is anhydrous ethanol; all raw materials are sieved through a 200-mesh screen before mixing. ​ 4. The method of claim 1, wherein the method further comprises: adding a phosphor to the mixture. In the step 2, the working frequency of the high-frequency induction heating system is 20kHz, the power density is 15kW / kg, and the heating uniformity deviation is less than ±3°C; the inner wall of the graphite mold is coated with a boron nitride release layer with a thickness of 20μm; the 600MPa uniaxial pressure is applied by a servo hydraulic system, the loading rate is 500MPa / s, the holding time is 0.8s, and the unloading rate is 300MPa / s.

5. The method for preparing the phosphorescent ceramic material according to claim 1, characterized in that: In the step 3, the green body is taken out of the graphite mold by a six-axis robot, and the surface of the green body is blown by a compressed air nozzle at a gas pressure of 0.4MPa to remove the loose powder and burrs at the edges.

6. The method for preparing the phosphorescent ceramic material according to claim 1, characterized in that: In the flash pulse treatment of the third temperature zone, the rapid temperature rise and fall is achieved by the silicon-molybdenum rod heating element arranged on both sides of the furnace and the top forced air cooling nozzle; the maximum output power of the silicon-molybdenum rod heating element is 120 kW, and the air volume of the forced air cooling nozzle is 2000 m³ / h, and the air pressure is 1.2 kPa.

7. The method for preparing the phosphorescent ceramic material according to claim 1, characterized in that: The step 5 controlled cooling and post-treatment specifically includes: forced convection cooling by high-purity nitrogen at a temperature interval of 900-650°C, a cooling rate of 80°C / min, and air cooling after the temperature drops below 650°C, followed by shot blasting treatment of the ceramic surface for 30s under a shot blasting pressure of 0.3 MPa using cast steel shots with a diameter of 0.8 mm; the forced convection cooling is performed in a cooling section, and the cooling gas is high-purity nitrogen; the shot blasting treatment is completed in a shot blasting treatment device, which is used to remove the surface oxide scale and introduce residual compressive stress.

8. The method for preparing the phosphorescent luminescent ceramic material according to claim 1, characterized in that: The step 6 detection and packaging includes: full inspection of the finished products by an online detection system, with a weight deviation controlled within ±0.5% and a key dimension tolerance controlled within ±0.1 mm; qualified products are automatically loaded into moisture-proof cartons by a moisture-proof packaging unit, and each carton loads 50 pieces.

9. A light-storing luminescent ceramic material, characterized by The luminescent ceramic material is prepared by the method according to any one of claims 1-8.

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