Visual mechanical luminescent ceramic, preparation method and application in grain mechanical equipment detection

Abstract

The invention discloses visual mechanical luminescent ceramic, a preparation method and application in grain mechanical equipment detection. The visual mechanical luminescent ceramic is prepared from beta-Ca3 (PO4) 2: 0.20 Tb < 3 + >, 0.10 Mn < 2 + > and xEu < 3 + >, wherein x is larger than or equal to 0.02 and smaller than or equal to 0.08, and the visual mechanical luminescent ceramic is prepared by combining a high-temperature solid-phase reaction method with an AM gel injection molding process. When the force colorimetric card is applied to grain mechanical equipment detection, the light emitting color of the force colorimetric card can be changed according to the magnitude of the stress, and a user can compare the light emitting color of the force colorimetric card with the force colorimetric card so as to intuitively observe the stress condition of the mechanical equipment. The limitation that stress can only be detected through a complex instrument in the prior art is broken through, the stress strain condition borne by equipment can be reflected in real time, key data support is provided for optimization of grain mechanical equipment structures and motion parameters, and grain quality and safety are guaranteed. Grain particle dynamic simulation can simulate movement of part of grain particles, but cannot accurately reflect stress and impact force, so that complex problems in actual processing are difficult to solve. The visual mechanical luminescent ceramic provided by the invention overcomes the defect, and provides a new technical scheme for the grain processing industry.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of fluorescent ceramics and visualization of mechanical stress, and particularly relates to a visual mechanical luminescent ceramic, a preparation method thereof, and an application thereof in the detection of grain machinery and equipment. Background Art

[0002] Grain, as a strategic material closely related to national economy and people's livelihood, is of self-evident importance. It is not only the basic guarantee for people's daily life, but also a key factor in maintaining social stability and promoting economic development. In the huge and complex system of the grain processing industry, grain machinery plays a crucial role and is the core key equipment to ensure the efficient production and processing of grain.

[0003] Since the initial cleaning stage of grain processing, the coordinated operation of various grain machinery is indispensable. The bucket elevator, with its stable and efficient characteristics, realizes the lifting of grain from a low position to a high position, laying the foundation for subsequent processing procedures. During the conveying process, the bucket elevator transports the grain to each designated position in an orderly manner according to the established procedure, effectively ensuring the continuity of the processing procedure. Entering the screening link, equipment such as hulling machines and rice milling machines each play their unique roles. The hulling machine can accurately remove the outer shell of paddy, and the rice milling machine further refines brown rice into white rice. Each processing step has a crucial impact on the final quality of the grain. However, in these seemingly conventional grain processing procedures, grain particles face a series of complex problems. Taking the pneumatic conveying link as an example, due to the initial conveying force, the grain will be subjected to extrusion and impact forces, and the grain particles will also collide and rub against each other frequently, which easily leads to problems such as impact breakage of grains, cracks generated after collision, and difficulty in ensuring quality. At present, although the kinetic simulation of grain particles can, to a certain extent, simulate the movement of grain particles, it cannot fully and accurately reflect the forces and impact forces of the grain particle flow, so it is difficult to completely solve the complex problems faced by grain particles in actual processing.

[0004] These machines that play an important role in grain processing are in a working environment of long-term heavy load, high friction, and complex materials for a long time. The mechanical components are constantly under great pressure and stress, which makes them extremely prone to various failures. For example, the common wear phenomenon will cause changes in the size and shape of the components, affecting the normal operation of the equipment; the deformation problem may reduce the fitting accuracy between the components and lower the processing efficiency; more seriously, once a fracture failure occurs, it will not only immediately interrupt the continuity of grain processing, resulting in production stagnation, but also have a negative impact on the quality of the processed grain, and may even trigger safety accidents, posing a serious threat to the lives of on-site workers and production facilities.

[0005] Therefore, it is of great significance to accurately and timely grasp the stress conditions of grain machinery for ensuring the safe and stable operation of equipment, improving production efficiency and product quality. It is like installing a pair of "intelligent eyes" on grain machinery, which can timely detect potential problems and take preventive and repair measures in advance, thus avoiding huge losses caused by equipment failures.

[0006] Currently, in the aspect of stress detection of grain machinery, most still rely on the method of regular manual inspections. Based on their accumulated experience, workers try to judge whether there are problems with the equipment by listening to the sounds emitted during equipment operation and attempting to detect abnormal changes in the sounds; or by observing the appearance of the equipment to check for obvious wear, deformation, etc. However, this detection method has many drawbacks. Firstly, it is highly subjective. Due to differences in experience and judgment criteria among different workers, different conclusions may be drawn about the state of the same equipment. Secondly, the accuracy is poor. Many subtle stress problems are difficult to detect through simple sound listening and observation, especially the stress conditions inside the equipment and in hidden parts, which are even more difficult to detect, easily leaving many potential safety hazards unnoticed. Moreover, manual inspections require shutdown operations, which will undoubtedly interrupt the continuous production of grain processing, affect the production progress, and cannot meet the urgent needs of modern grain processing enterprises for efficient and continuous production.

[0007] Although some grain machinery uses pressure sensors, strain gauges and other devices to detect the stress, these methods are not perfect either. The installation positions of sensors are often restricted by many factors, and they can only obtain the stress data of local parts of the equipment, unable to comprehensively and accurately reflect the overall stress distribution of the equipment. In a complex grain processing environment, sensors are extremely vulnerable to factors such as dust, humidity, and high temperature. Dust may cover the surface of the sensor, affecting the transmission of its signal; a humid environment may cause a short circuit in the internal circuit of the sensor; high temperature may change the performance of the sensor, all of which may lead to a decrease in detection accuracy or even cause the sensor to malfunction directly. In addition, the maintenance cost of sensors is relatively high, and they need to be calibrated and maintained regularly, increasing the operating cost of the enterprise. Moreover, the collection and analysis of sensor detection data require professional equipment and high technical requirements for operators, which to a certain extent limits their wide application in actual production and is not conducive to real-time monitoring and rapid response to the stress conditions of the equipment.

[0008] In recent years, with the rapid development of materials science, new luminescent materials have emerged in large numbers, and among them, mechanoluminescent materials have made significant breakthroughs. Such materials have unique properties. When subjected to external forces, their luminescent characteristics, such as luminescence intensity, color, etc., will change significantly. Moreover, they also have the advantages of fast response speed and high sensitivity, and can quickly and accurately respond to external force changes. It is precisely because of these excellent characteristics that mechanoluminescent materials have attracted more and more attention from scholars and scientists, and are expected to bring new solutions to the field of force detection in grain machinery, injecting new vitality into ensuring the safe and efficient development of the grain processing industry.

[0009] Chinese Patent (CN 119351095 A) discloses a high-brightness piezoelectric mechanoluminescent material, its preparation method and application. The preparation method used is a high-temperature solid-phase reaction method combined with resin to form a visual material, and its luminescent color is relatively single.

[0010] Chinese Patent (CN 119331608 A) discloses a force-induced luminescent composite material, its preparation method and application. The force-induced luminescent composite material includes aluminate modified by metal fluoride and rare-earth doped ions doped in the fluoride-modified aluminate, and a heterojunction is formed between the aluminate and the metal fluoride, and its main application is in force-induced composite elastomers.

[0011] Chinese Patent (CN 116554870 A) discloses a new type of green mechanoluminescent phosphor, its preparation method and application. It prepares Sr 2-x Ga2GeO7: x Tb 3+ . The final prepared product is a powdery phosphor, and the application field is not clearly proposed in the text.

[0012] Chinese Patent (CN 119355866 A) discloses a force-induced luminescent optical fiber, its preparation method and a distributed stress sensing system. The system is composed of a force-induced luminescent optical fiber, a support unit, a connecting optical fiber and a detector.

[0013] Chinese Patent (CN 119039962 A) discloses a reversible mechanochromic fluorescent material and its application in self-erasing writing. Its aggregation mode is to self-aggregate into a nanosheet structure through hydrophilic-hydrophobic interaction in water, and remove the solvent to obtain a supramolecular nano-powder with blue fluorescence, and its main application field is the self-erasing writing field.

[0014] Chinese Patent (CN 118005600 A) discloses a force-induced response luminescent material and its application in the detection field. The detection field mentioned in this patent is one of goods, films or fabrics.

[0015] In summary, the application of mechanoluminescent ceramics in the field of grain machinery is of great significance. When grain machinery is in operation, it is difficult for traditional detection means to accurately grasp its stress condition, resulting in easy breakage of grain kernels due to uneven mechanical stress during the conveying and processing processes, which affects the quality. Mechanoluminescent ceramics can feedback mechanical stress in real time through changes in their own luminescence characteristics. Applying it to key components of grain machinery can comprehensively monitor stress and provide data support for optimizing the lossless flow conveying of grain kernels. Achieving comprehensive, real-time, and accurate stress monitoring of grain machinery can also reduce the detection cost, improve the detection efficiency, and promote the development of the grain processing industry towards intelligence and safety, with important practical significance and broad application prospects. Summary of the Invention

[0016] The main technical problem to be solved by the present invention is mainly aimed at the problem that when current grain machinery is in operation, traditional detection means are difficult to accurately grasp its stress condition, resulting in easy breakage of grain kernels due to uneven mechanical stress during the conveying and processing processes, thus affecting the quality. A preparation and application of visible mechanoluminescent ceramics for grain machinery is proposed. This mechanoluminescent ceramics can be applied to the outside of grain machinery to measure its own stress condition through changes in its own luminescence characteristics and feedback mechanical stress in real time. Applying it to key components of grain machinery can comprehensively monitor stress and provide data support for optimizing the lossless flow conveying of grain kernels.

[0017] To solve the above technical problems, the present invention adopts the following technical solutions: The present invention uses AM gel casting to prepare mechanoluminescent ceramics. Through the material-structure-function collaborative design strategy, an innovative composite structure of a three-dimensional gel network skeleton and a stress response unit is utilized to achieve the integration of precise forming of complex shapes and high-efficiency mechanoluminescent performance. Its core structure is based on a homogeneous mixture system of acrylamide prepolymer solution (containing cross-linking agent and initiator) and mechanoluminescent ceramic powder (such as Ca3(PO4)2:Tb 3 + , Ca3(PO4)2:Mn 2+ , Ca3(PO4)2:Eu 3+ ). The ceramic is prepared by combining high-temperature solid-phase method with AM gel casting technology through two-stage sintering (low-temperature debinding + high-temperature densification). This design enables the green body to still maintain a density as high as 98% after drying and sintering (1750 - 1900 °C), and then a mechanoluminescent ceramic with high green body strength (flexural strength > 150 MPa) and fast stress-light conversion efficiency is obtained. This material carefully selects transition metal ions Mn 2+ with different sensitivities and rare earth ions Tb 3+, using it as the luminescence center and fully considering the influence of shallow trap states, successfully promoted the material to achieve a change in the dynamic colorimetric fluorescence intensity, and finally achieved the effect of bicolor change, capable of emitting visible light in the range of 500 - 750 nm under friction, extrusion or impact. This material can be applied to grain machinery and equipment, and can reflect the stress and strain conditions suffered by the equipment in real time, thereby providing key data support and technical basis for the optimization of grain machinery and equipment, helping to solve various problems in the process of grain transportation and storage, and ensuring the quality and safety of grain.

[0018] Specifically as follows: A visual mechano-luminescent ceramic, the composition of the visual mechano-luminescent ceramic is β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ , where 0.02 ≤ x ≤ 0.08.

[0019] The preparation method of the visual mechano-luminescent ceramic described in the present invention adopts the high-temperature solid-phase method combined with the AM gel-casting molding technology, and realizes a visual mechano-luminescent ceramic with high green body strength (flexural strength > 150 MPa) and fast stress-light conversion efficiency (response time < 10 ms) through two-stage sintering of low-temperature debinding + high-temperature densification. Specifically, it includes the following steps: (1) Prepare a uniformly mixed ceramic precursor powder by the high-temperature solid-phase method: Introduce terbium (Tb), manganese (Mn), and europium (Eu) elements into the main structure with the composition of Ca3(PO4)2, and obtain a uniformly mixed Ca3(PO4)2:Tb 3 + , Ca3(PO4)2: Mn 2+ , Ca3(PO4)2: Eu 3+ mixture powder, forming β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ visual mechano-luminescent precursor ceramic powder, where 0.02 ≤ x ≤ 0.08; (2) Prepare β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ visual mechano-luminescent ceramic by the AM gel-casting molding technology.

[0020] Furthermore, the preparation method of the ceramic precursor powder in step (1) is as follows: Precisely weigh the raw materials of CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, and Eu2O3 according to a certain stoichiometric ratio, and after mixing, obtain Ca3(PO4)2:Tb 3+ , Ca3(PO4)2:Mn 2+ , Ca3(PO4)2:Eu 3+ mixture powder. After ball milling, drying, grinding and sieving, obtain refined powder; then transfer the obtained uniform mixture to an alumina crucible for sintering. After cooling to room temperature, grind the sintered sample again.

[0021] Furthermore, CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, and Eu2O3 are all high-purity powders with a powder purity > 99.9%. The molar ratio of the CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, and Eu2O3 powders is 3:2:0.2:0.1:(0.01 - 0.04).

[0022] Furthermore, the ball milling uses a nylon ball milling tank with alcohol as the solvent. The mass ratio of the ball medium to the mixture powder during ball milling is 2:1. The rotation speed of the ball milling is 150 - 160 r / min, and the ball milling time is 20 - 22 h; the drying temperature is 65 - 75 °C, and the drying time is 20 - 22 h; the grinding is carried out in an agate mortar containing ethanol; the sintering temperature is 1100 - 1400 °C, the sintering time is 2 - 4 h, the heating rate during sintering is 5 - 6 °C / min, the cooling rate during sintering is 5 - 10 °C / min, and grind again for 3 - 5 min.

[0023] Furthermore, step (2) is prepared by using the AM gel-casting forming technology β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ Visual mechanical luminescent ceramics. When using gel-casting to prepare the ceramic green body, the monomer is acrylamide (AM); the cross-linking agent is N,N'-methylenebisacrylamide (MBAM); the dispersant is ammonium citrate (TAC); the pH regulator is tetramethylammonium hydroxide (TMAH); the initiator is ammonium persulfate solution (APS). The specific method is as follows: 1) Prepare the slurry: Add the ceramic precursor powder to the ball milling tank, load alumina grinding balls and deionized water into the ball milling tank, and then add the monomer acrylamide, the cross-linking agent N,N'-methylenebisacrylamide, the dispersant ammonium citrate, and the pH regulator tetramethylammonium hydroxide solution for ball milling to obtain the slurry; 2) Preparation of green body: Wait until the slurry in step 1) is evenly ball-milled and dispersed. Pour the slurry into a degassing tank through a sieve, add a catalyst, place it in a vacuum degassing machine for degassing, then add an initiator, stir evenly to avoid introducing air bubbles, and then pour it into a mold. Let it stand and dry in a drying oven to obtain a ceramic green body. After drying, perform demolding treatment, and place the demolded green body in a muffle furnace for binder burnout; 3) Preparation of mechanoluminescent ceramics: Place the binder-burned ceramics obtained in step 2) into a vacuum sintering furnace for sintering to obtain pure-phase ceramics. Anneal and polish the pure-phase ceramics, and finally obtain β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ mechanoluminescent ceramics.

[0024] Furthermore, in step 1), the ceramic precursor powder is added to the ball-milling tank in two portions, the ball-milling time is 2 - 4 h, the mass percentage of acrylamide in the ceramic precursor powder is 3 - 5 wt%, the mass percentage of N,N'-methylenebisacrylamide in the ceramic precursor powder is 0.1 - 0.3 wt%, the mass percentage of ammonium citrate in the ceramic precursor powder is 0.01 - 0.03 wt%, the mass percentage of tetramethylammonium hydroxide in the tetramethylammonium hydroxide solution in the ceramic precursor powder is 1.0 - 1.3 wt%, and the solid content of the obtained slurry is 45 - 55 wt%.

[0025] Furthermore, in step 2), the catalyst is a tetramethylethylenediamine solution, and the tetramethylethylenediamine in the tetramethylethylenediamine solution accounts for 20 - 30 wt% of the mass of the ceramic precursor powder; the initiator is an ammonium persulfate solution, and the ammonium persulfate in the ammonium persulfate solution accounts for 2 - 4 wt% of the mass of the ceramic precursor powder; the degassing time in the vacuum degassing machine in step 2) is 30 - 45 min; the drying is carried out in a drying oven at 45 °C and 75 °C for 20 - 22 h respectively; the specific steps for binder burnout of the demolded green body are: first, burn the green body at 100 - 200 °C for 5 - 7 h, then cool it to room temperature with a heating and cooling rate of 0.5 - 1 °C / min; then burn the green body at 450 - 550 °C for 5 - 7 h, and then cool it to room temperature with a heating and cooling rate of 1 - 2 °C / min; finally, burn the green body at 750 - 850 °C for 5 - 7 h, and then cool it to room temperature with a heating and cooling rate of 1 - 2 °C / min.

[0026] Furthermore, in step 3), the vacuum degree during sintering is greater than 5.1 × 10 -4 Pa, specifically 10 -2 ~10 -4Pa, the sintering temperature is 1750 - 1900 °C, the sintering time is 9 - 11 h, the annealing treatment in step 3) is carried out in an air atmosphere, the temperature of the annealing treatment is 1350 - 1450 °C, and the annealing time is 3 - 5 h.

[0027] The present invention also provides the application of the visualized mechanoluminescent ceramic in the detection of grain machinery and equipment. When it is applied to the pressure-sensing ceramic of grain machinery, it can achieve accurate and visualized color changes, can reflect the stress and strain conditions suffered by the equipment in real time, and optimize grain machinery.

[0028] Provided by the present invention β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ A preparation method and application of a mechanoluminescent ceramic. This method does not require expensive and complex equipment, nor does it have special material requirements for the mold, reducing the input cost of production equipment. It is a low-cost forming technology. Moreover, it can form ceramic parts of various complex shapes and sizes, meeting the diverse requirements of different components in grain machinery for the shape and size of the mechanoluminescent ceramic. For example, special-shaped ceramic components that fit specific mechanical structures can be prepared.

[0029] The mechanoluminescent ceramic of the present invention can keenly sense the mechanical stress changes generated during the operation of grain machinery. When grain machinery is operating, it is difficult for traditional detection means to accurately grasp its stress condition, resulting in easy breakage of grain kernels due to uneven mechanical stress during the conveying and processing processes, affecting the quality. The mechanoluminescent ceramic will emit light signals of different intensities and colors due to the change in stress. Based on the information provided by the mechanoluminescent ceramic, grain machinery can be optimized in many aspects. It can analyze the frequently occurring stress abnormal parts and redesign or improve the component structure. It can also reasonably adjust parameters such as the rotation speed and load of the machinery according to the stress conditions of the machinery under different working conditions fed back by the ceramic, so that it operates in a more efficient and stable state. In this way, the mechanoluminescent ceramic helps grain machinery achieve an all-round improvement from fault detection to performance optimization, ensuring the efficiency and safety of grain production.

[0030] The normal operation of grain machinery is directly related to the safety and quality of grain production. Through the effective monitoring of the operation status of grain machinery by mechanoluminescent ceramics, potential faults can be eliminated in a timely manner, avoiding problems such as grain contamination and production accidents caused by mechanical failures, ensuring the safety of the grain production process, and also guaranteeing that the quality of the grain during the processing process is not affected by equipment failures, providing a strong guarantee for safe and high-quality grain production. When grain machinery is working, various working conditions may occur, resulting in grain losses. Therefore, a convenient detection method is needed to timely understand the working conditions of grain machinery and reduce losses in this regard. Moreover, the mechanoluminescent ceramics provided by the present invention have the characteristics of large size, complex shape, and high visibility, which can meet the application requirements of mechanoluminescent ceramics in grain machinery.

[0031] The present invention combines the advantages of ceramics, and products made of this material can maintain good performance under complex and changeable environmental conditions. It can sensitively detect the changes in the impact force received by grain machinery, and has obvious color changes, enabling a more intuitive perception of the magnitude of stress and strain received by grain machinery, thus making more rapid optimization and adjustment of grain machinery, ultimately improving the reliability and economy of the entire grain machinery.

[0032] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a visual mechanoluminescent ceramic, which can real-time sense the force and impact force of the grain particle flow when applied to grain processing equipment, helping to adjust equipment parameters, reducing the breakage rate caused by uneven force during grain processing, improving grain quality and processing efficiency, and strongly guaranteeing the efficient and stable development of the grain processing industry, solving the long-existing practical problems in the grain processing field.

[0033] The present invention provides a visual mechanoluminescent ceramic, which can collect the luminescence data of mechanoluminescent ceramics under different working conditions, providing a basis for the optimized design of grain machinery, helping to develop more efficient and durable equipment, and enhancing product competitiveness.

[0034] The present invention provides a visual mechanoluminescent ceramic, which has a large response range, ranging from 250 to 1000 N. Moreover, in different production links of grain machinery, such as conveying, grinding, screening, etc., the mechanical forces such as pressure and friction received by each part vary greatly. The large mechanoluminescence threshold range enables the material to effectively emit light under various working conditions such as light load and heavy load of grain machinery, accurately reflecting the stress situation.

[0035] The present invention provides a visual mechano-luminescent ceramic, which can sensitively detect the microscopic structural changes in the early stage of thermal fatigue of grain machinery components that have been working in a temperature-changing environment for a long time through the change of luminescence characteristics, provide early maintenance signals for equipment maintenance personnel, avoid serious failures caused by thermal fatigue, and extend the service life of the equipment.

[0036] The present invention provides a visual mechano-luminescent ceramic, in which Ca3(PO4)2 is the main component, which is a mechano-luminescent material that will generate a response and emit light when subjected to mechanical force. The latter three are auxiliary elements that control the luminescence color and brightness, where Tb 3+ acts as a green luminescence center; Mn 2+ acts as a dual-functional role, being both an orange / red luminescence center and participating in the formation of defect or trap energy levels; Eu 3+ is a red luminescence center that adjusts the luminescence color and participates in energy transfer. The present invention realizes the change of dynamic colorimetric fluorescence intensity and thus realizes the two-color change by selecting transition metal ions Mn 2+ and rare earth ions Tb 3+ as luminescence centers and combining the influence of shallow trap states. At the same time, in order to improve the visual effect, Eu 3+ is added to adjust the luminescence color and energy transfer. Through energy transfer and color superposition, the luminescence centers of Tb 3+ and Mn 2+ are activated; thus realizing the adjustable luminescence color change of the material (green light → red light). BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 is a process flow chart for the preparation of the visual mechano-luminescent ceramic of the present invention.

[0039] Figure 2 is the XRD pattern of β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ ( x =0,0.01,0.03,0.04) prepared in Examples 1-3 and Comparative Example 1; Figure 3 is the β -Ca3(PO4)2:0.20Tb prepared in Examples 1-3 and Comparative Example 13+ , 0.10Mn 2+ , x Eu 3+ ( x = 0, 0.01, 0.03, 0.04) Mechanoluminescence spectrum diagram. Detailed implementation mode

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] In the following examples, the mass percentage purity of the CaCO3 raw material is ≥99.9%; the mass percentage purity of the (NH4)2HPO4 raw material is ≥99.9%; the mass percentage purity of the Tb4O7 raw material is ≥99.9%; the mass percentage purity of the MnCO3 raw material is ≥99.9%; the mass percentage purity of the Eu2O3 raw material is ≥99.9%.

[0042] Example 1 A β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ ( x = 0.02) Preparation method of visual mechanoluminescent ceramics, as Figure 1 shown, the specific steps are as follows: (1) According to the preparation of 60 g of β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ mechanoluminescent ceramic powder, respectively weigh CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, Eu2O3, with a molar ratio of 3:2:0.2:0.1:0.01, add them to a nylon ball mill tank with alcohol as the solvent and ball mill for 22 h to obtain a uniform oxide mixture powder. The mass ratio of the ball medium to the oxide mixture powder (i.e., the ball-to-material ratio) is 2:1, and the ball milling speed is 160 r / min; separate the oxide mixture powder slurry and dry it at 75 °C for 22 hours. Grind the dried powder in a mortar with anhydrous ethanol as the medium, then screen it, and then transfer the obtained uniform mixed powder to an alumina crucible. Then place the refined powder in a muffle furnace and calcine it at 1100 °C for 4 h, then cool it at room temperature, and finally grind it in a mortar for 5 minutes to obtain uniform and well-sintered active β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu3+ Precursor powder; (2)Slurry preparation: Using the AM gel-casting preparation process, obtain β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ slurry, and the specific process is as follows: Add the precursor powder obtained in step (1) β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ to a ball mill tank containing acrylamide (3 wt%, relative to the powder), N,N'-methylenebisacrylamide (0.1 wt%, relative to the powder), ammonium citrate (0.03 wt%, relative to the powder), tetramethylammonium hydroxide solution (1.0 wt%, relative to the powder), pure water (to make the solid content of the finally obtained slurry 55 wt%), and alumina grinding balls, and ball mill for 4 h, β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ The precursor powder can be added in two portions.

[0043] (3)Green body preparation: Wait for the slurry in step (2) to be evenly ball milled and dispersed, pour the slurry into a defoaming tank through a sieve, prepare a catalyst solution of tetramethylethylenediamine (30 wt%, relative to the powder) and an initiator solution of ammonium persulfate (4 wt%, relative to the powder) with a pipette. The solution may become ineffective after a long time. Prepare 10 ml, and the standing time should not be too long, usually 1 day. Then add 120 μl of the catalyst tetramethylethylenediamine solution, put it into a vacuum defoaming machine to defoam for 30 min, add 240 μl of the initiator ammonium persulfate solution, inject the slurry into a circular mold, and then place the green body in drying ovens at 45 °C and 75 °C for 22 h respectively, and then perform demolding treatment. Put the demolded green body into a muffle furnace for debinding. First, sinter the green body at 200 °C for 5 h, then cool to room temperature with a heating and cooling rate of 1 °C / min; then sinter the green body at 550 °C for 5 h, and then cool to room temperature with a heating and cooling rate of 1 °C / min; finally, sinter the green body at 850 °C for 5 h, and then cool to room temperature with a heating and cooling rate of 1 °C / min. Subsequently, a dense green body is obtained.

[0044] (4)Sintering: The β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+The dense green body is placed in a vacuum environment with a vacuum degree of 10 -2 Pa, sintered at 1900 °C for 9 hours to obtain a pure-phase ceramic; (5)Annealing treatment: The sintered pure-phase ceramic sample is kept at 1450 °C for 3 h in an air atmosphere and polished to obtain a β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ visualized mechanoluminescent ceramic with a flexural strength of 160 MPa and a stress-optical conversion response time of 9 ms.

[0045] Example 2 A β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ ( x =0.06) Preparation method of visualized mechanoluminescent ceramic, as Figure 1 shown, the specific steps are: (1)According to the preparation of 60 g of β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ mechanoluminescent ceramic, respectively weigh CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, Eu2O3, with a molar ratio of 3:2:0.2:0.1:0.03, add them to a nylon ball mill tank with alcohol as the solvent and ball mill for 21 h to obtain a uniform oxide mixed powder. The mass ratio of the ball medium to the oxide mixed powder (i.e., the ball-to-material ratio) is 2:1, and the ball mill rotation speed is 155 r / min; separate the oxide mixed powder slurry, dry it at 70 °C for 21 h, grind the dried powder in a mortar with anhydrous ethanol as the medium, then screen it, and then transfer the obtained uniform mixed powder to an alumina crucible. Then place the refined powder in a muffle furnace and calcine it at 1300 °C for 3 h, then cool it at room temperature, and finally grind it in a mortar for 4 minutes to obtain a uniform and well-sintered β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ precursor powder; (2)Slurry preparation: Adopt the AM gel-casting preparation process to obtain β-Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ Slurry, the specific process is as follows: Add the precursor powder obtained in step (1) β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ into a ball mill tank containing acrylamide (4 wt%, relative to the powder), N,N'-methylenebisacrylamide (0.2 wt%, relative to the powder), ammonium citrate (0.02 wt%, relative to the powder), tetramethylammonium hydroxide solution (1.1 wt%, relative to the powder), pure water (to make the solid content of the finally obtained slurry 50 wt%), and alumina grinding balls, and ball mill for 3 h. Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ The precursor powder can be added in two portions.

[0046] (3) Prepare the green body: Wait for the slurry in step (2) to be evenly dispersed by ball milling, pour the slurry into a defoaming tank through a sieve, prepare a solution of catalyst N,N,N',N'-tetramethylethylenediamine (25 wt%, relative to the powder) and initiator ammonium persulfate (3 wt%, relative to the powder) with a pipette, then add 120 μL of the above-prepared catalyst, place it in a vacuum defoaming machine to defoam for 40 min, add 240 μL of the initiator, inject the slurry into a circular mold, then place the green body in drying ovens at 45 °C and 75 °C and dry for 21 h respectively, then perform demolding treatment, place the demolded green body in a muffle furnace for debinding, first burn the green body at 150 °C for 6 h, then cool to room temperature with a heating and cooling rate of 1 °C / min; then burn the green body at 400 °C for 6 h, then cool to room temperature with a heating and cooling rate of 1 °C / min; finally burn the green body at 800 °C for 6 h, then cool to room temperature with a heating and cooling rate of 2 °C / min. Subsequently, a dense green body is obtained.

[0047] (4) Sintering: Place the dense green body of Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ in a vacuum environment with a vacuum degree of 10 -3 Pa, sinter at 1800 °C for 10 h to obtain a pure-phase ceramic; (5) Annealing treatment: The sintered pure-phase ceramic samples were kept at 1400 °C for 4 h in an air atmosphere and polished to obtain a visible mechanical luminescence ceramic with a flexural strength of 158 MPa and a stress-optical conversion response time of 6 ms. β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ visible mechanical luminescence ceramic.

[0048] Example 3 A β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ ( x =0.08) Preparation method of visible mechanical luminescence ceramic, as Figure 1 shown, the specific steps are: (1) According to the preparation of 60 g of β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ mechanoluminescent ceramic powder, weigh CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, Eu2O3 respectively, with a molar ratio of 3:2:0.2:0.1:0.04, add them to a nylon ball mill tank with alcohol as the solvent and ball mill for 20 h to obtain a uniform oxide mixed powder. The mass ratio of the ball medium to the oxide mixed powder (i.e., the ball-to-material ratio) is 2:1, and the ball mill speed is 150 r / min; separate the oxide mixed powder slurry and dry it at 65 °C for 20 hours. Grind the dried powder in a mortar with anhydrous ethanol as the medium, then screen it, and then transfer the obtained uniform mixed powder to an alumina crucible. Then place the refined powder in a muffle furnace and calcine it at 1400 °C for 2 h, then cool it at room temperature, and finally grind it in a mortar for 3 minutes to obtain a uniform and well-sintered β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ precursor powder; (2) Slurry preparation: Use the AM gel-casting preparation process to obtain β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+Slurry, the specific process is as follows: The β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ precursor powder is added to a ball milling tank containing acrylamide (3 wt%, relative to the powder), N,N'-methylenebisacrylamide (0.1 wt%, relative to the powder), ammonium citrate (0.03 wt%, relative to the powder), tetramethylammonium hydroxide solution (1.3 wt%, relative to the powder), pure water (to make the solid content of the finally obtained slurry 45 wt%), and alumina grinding balls, and ball milled for 2 h in the ball milling tank. β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ The precursor powder can be added in two portions.

[0049] (3) Preparation of green body: Wait for the slurry in step (2) to be uniformly ball milled and dispersed, pour the slurry into a defoaming tank through a sieve, prepare a solution of catalyst tetramethylethylenediamine (20 wt%, relative to the powder) and initiator ammonium persulfate (2 wt%, relative to the powder) with a pipette. After the slurry is filtered to remove the grinding balls, add 120 μL of the above-prepared catalyst, place it in a vacuum defoaming machine to defoam for 45 min, add 240 μL of the initiator, inject the slurry into a circular mold, then place the green body in drying ovens at 45 °C and 75 °C respectively for 20 h, and then perform demolding treatment. Place the demolded green body in a muffle furnace for debinding. First, burn the green body at 100 °C for 7 h, then cool it to room temperature with a heating and cooling rate of 0.5 °C / min; then debind the green body at 450 °C for 7 h, and then cool it to room temperature with a heating and cooling rate of 2 °C / min; finally, debind the green body at 750 °C for 7 h, and then cool it to room temperature with a heating and cooling rate of 2 °C / min. Subsequently, a dense green body is obtained.

[0050] (4) Sintering: Place the β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ dense green body in a vacuum environment with a vacuum degree of 10 -4 Pa and sinter at 1750 °C for 11 h to obtain a pure-phase ceramic; (5) Annealing treatment: Keep the sintered pure-phase ceramic sample in an air atmosphere at 1350 °C for 5 h and perform polishing treatment, then a sample with a flexural strength of 152 MPa and a stress-optical conversion response time of 8 ms is obtained. β-Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ Visual mechanical luminescence ceramics.

[0051] Comparative Example 1 A β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ ( x = 0.00) Preparation method of visual mechanical luminescence ceramics, as Figure 1 shown, the specific steps are: (1) According to the preparation of 60 g of β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ For the mechanical luminescence ceramic powder, weigh CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, Eu2O3 respectively, with a molar ratio of 3:2:0.2:0.1:0. Add them to a nylon ball mill tank with alcohol as the solvent and ball mill for 22 h to obtain a uniform oxide mixture powder. The mass ratio of the ball medium to the oxide mixture powder (i.e., the ball-to-material ratio) is 2:1, and the ball mill speed is 160 r / min. Separate the oxide mixture powder slurry and dry it at 75 °C for 22 h. Grind the dried powder in a mortar with anhydrous ethanol as the medium, then screen it. Then transfer the obtained uniform mixed powder to an alumina crucible, and place the refined powder in a muffle furnace and calcine it at 1100 °C for 4 h, then cool it at room temperature, and finally grind it in a mortar for 5 minutes to obtain uniform and well-sintered β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ precursor powder; (2) Slurry preparation: Adopt the AM gel-casting preparation process to obtain β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ , x Eu 3+ slurry. The specific process is as follows: The β -Ca3(PO4)2:0.20Tb 3+ , 0.10Mn 2+ ,x Eu 3+ The precursor powder was added to a ball milling tank containing acrylamide (3 wt%, relative to the powder), N,N'-methylenebisacrylamide (0.1 wt%, relative to the powder), ammonium citrate (0.03 wt%, relative to the powder), tetramethylammonium hydroxide solution (1.0 wt%, relative to the powder), pure water (to make the solid content of the finally obtained slurry 55 wt%), and alumina grinding balls, and ball milled for 4 h. β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ The precursor powder can be added in two portions.

[0052] (3) Preparation of green body: Wait for the slurry in step (2) to be evenly dispersed by ball milling. Pour the slurry into a defoaming tank through a sieve. Prepare a solution of catalyst tetramethylethylenediamine (30 wt%, relative to the powder) and initiator ammonium persulfate solution (4 wt%, relative to the powder) with a pipette. The solution may become ineffective after a long time. Prepare 10 ml and the standing time should not be too long, usually 1 day. Then add 120 μl of the catalyst tetramethylethylenediamine solution, put it into a vacuum defoaming machine to defoam for 30 min, add 240 μl of the initiator ammonium persulfate solution, inject the slurry into a circular mold, and then place the green body in drying ovens at 45 °C and 75 °C respectively for 22 h. Subsequently, perform demolding treatment. Place the demolded green body in a muffle furnace for debinding. First, sinter the green body at 200 °C for 5 h, then cool it to room temperature with a heating and cooling rate of 1 °C / min; then sinter the green body at 550 °C for 5 h and then cool it to room temperature with a heating and cooling rate of 1 °C / min; finally, sinter the green body at 850 °C for 5 h and then cool it to room temperature with a heating and cooling rate of 1 °C / min. Subsequently, a dense green body is obtained.

[0053] (4) Sintering: The β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ dense green body was placed in a vacuum environment with a vacuum degree of 10 -2 Pa and sintered at 1900 °C for 9 h to obtain a pure-phase ceramic; (5) Annealing treatment: The sintered pure-phase ceramic sample was held at 1450 °C for 3 h in an air atmosphere and polished, and then an α β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu3+ Visualized mechanoluminescent ceramics

[0054] In the above embodiments, the mechanoluminescence brightness of the sample prepared in Embodiment 2 is the strongest. It can be observed by the naked eye and has good repeatability. Therefore, it is preferably 0.06 ≤ x ≤ 0.08, and most preferably x = 0.06.

[0055] Application Example 1 The present invention β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ The visualized mechanoluminescent ceramics are prepared by adopting a high-temperature solid-phase reaction method combined with an AM gel-casting molding process, and are innovatively applied to the field of intelligent monitoring and optimization of grain machinery: by customizing the preparation of special-shaped ceramic sensors that are accurately matched with the complex structures of equipment (such as the root of the spiral conveyor blade, the support beam of the vibrating screen frame, or the inner wall of the polishing machine drum), and using their stress-luminescence response characteristics, the visualization mapping of the dynamic stress distribution is realized.

[0056] In the grain storage process, problems such as grain impact and breakage, cracks generated after collisions, and difficult-to-guarantee quality have long troubled warehouse management. Although the dynamics simulation of grain particles can simulate the movement of grain particles to a certain extent, it is still impossible to fully and accurately reflect the forces and impact forces on the grain particle flow. In view of this, the present invention designs a kind of mechanoluminescent ceramic, which can be laid around the side of the granary at a suitable height to strive for accurate monitoring of the grain storage situation. As the grain starts to be stored in the warehouse, the grain particles gradually accumulate and exert pressure on the side wall of the warehouse. When the pressure reaches 250N, the mechanoluminescent material starts to emit a faint green light, indicating that the grain accumulation has generated a detectable pressure on it, and the staff can thus know that the grain accumulation height has reached near the material laying position. As the grain continues to accumulate, the pressure gradually rises. When the pressure reaches 500N, the intensity of the green light significantly increases. At this time, through the monitoring system, the warehouse manager can clearly see the area covered by the green light, and then, based on the difference in the brightness of the green light, roughly judge the accumulation range and pressure distribution of the grain at this height level. For example, a brighter green light indicates that the grain accumulation here is relatively dense and the pressure is greater; a slightly darker green light indicates that the grain accumulation is relatively loose and the pressure is smaller. This helps to prevent in advance the excessive extrusion and collision between grain particles due to uneven local pressure, resulting in cracks or breakage. As the grain accumulation approaches full storage, the pressure continues to rise. When the pressure approaches 1000N, the light emitted by the mechanoluminescent material gradually changes from green to yellow-green, and then to orange-red. When the pressure finally reaches 1000N, the material emits a bright red light, warning the staff that the granary is about to reach its load limit. This can not only avoid damage to the warehouse wall caused by excessive pressure, but also prevent the grain from generating a large potential energy at a high place due to excessive accumulation, falling and impacting the lower grain, thus damaging the grain quality.

[0057] The present invention is prepared by a high-temperature solid-state reaction method combined with an AM gel in-mold forming process, and a visual mechanoluminescent ceramic with both high green body strength and fast stress-light conversion efficiency is obtained through two-stage sintering of low-temperature binder burnout + high-temperature densification. When it is applied to the detection of grain machinery and equipment, it can change its own luminescent color according to the magnitude of the stress it receives. The user can compare its luminescent color with a force colorimetric card, and then intuitively observe the stress situation of the machinery and equipment. It breaks through the limitation of only being able to detect stress through complex instruments in the past, can reflect the stress and strain situation of the equipment in real time, provides key data support for the optimization of the structure and motion parameters of grain machinery and equipment, and guarantees the quality and safety of grain. It is worth mentioning that although the dynamics simulation of grain particles can simulate the movement of grain particles to a certain extent, it cannot fully and accurately reflect the forces and impact forces on the grain particle flow, and it is difficult to completely solve the complex problems faced by grain particles in actual processing. The visual mechanoluminescent ceramic of the present invention makes up for this deficiency and brings a new technical solution to the grain processing industry.

[0058] Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A visual mechanoluminescent ceramic, characterized in that: The composition of the visualized mechanical luminescent ceramic is β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ , where 0.02≤ x ≤0.

08.

2. The method for preparing the visualized mechanoluminescent ceramic according to claim 1, characterized in that: The high-temperature solid phase method is combined with AM gel injection molding technology, and the visual mechanical luminescent ceramics with high green body strength and rapid stress-light conversion efficiency are realized through low-temperature debinding + high-temperature densification two-stage sintering, which specifically includes the following steps: (1) Preparation of uniformly mixed ceramic precursor powder by high temperature solid phase method: Terbium (Tb), manganese (Mn) and europium (Eu) elements were introduced into the main structure of Ca3(PO4)2, and uniformly mixed Ca3(PO4)2:Tb was obtained by high temperature solid phase method. 3+ 、Ca3(PO4)2: Mn 2+ 、Ca3(PO4)2: Eu 3+ The mixture powder is formed β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3 + Visualization of mechanical luminescence precursor ceramic powder, where 0.02≤ x ≤0.08; (2) Preparation using AM gel injection molding technology β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ Visualizing mechanoluminescent ceramics.

3. The method for preparing the visualized mechanoluminescent ceramic according to claim 2, characterized in that: The preparation method of the ceramic precursor powder in step (1) is as follows: CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, and Eu2O3 are accurately weighed according to a certain stoichiometric ratio, and mixed to obtain Ca3(PO4)2:Tb 3+ 、Ca3(PO4)2: Mn 2+ 、Ca3(PO4)2: Eu 3+ The mixture powder is ball-milled, dried, ground and sieved to obtain a fine powder; the uniform mixture is then transferred to an alumina crucible for sintering, and after cooling to room temperature, the sintered sample is ground again.

4. The method for preparing the visualized mechanoluminescent ceramic according to claim 3, characterized in that: CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, and Eu2O3 are all high-purity powders with a powder purity of >99.9%. The molar ratio of the CaCO3, (NH4)2HPO4, Tb4O7, MnCO3, and Eu2O3 powders is 3:2:0.2:0.1:(0.01~0.04).

5. The method for preparing the visualized mechanoluminescent ceramic according to claim 3, characterized in that: The ball mill adopts a nylon ball milling jar with alcohol as solvent, the mass ratio of ball medium to mixture powder is 2:1, the rotation speed of the ball mill is 150-160r / min, and the ball milling time is 20-22h; the drying temperature is 65-75°C, and the drying time is 20-22h; the grinding is grinding in an agate mortar containing ethanol; the sintering temperature is 1100-1400°C, the sintering time is 2-4h, the heating rate during sintering is 5-6°C / min, and the cooling rate during sintering is 5-10°C / min.

6. The method for preparing the visualized mechanoluminescent ceramic according to claim 3, characterized in that: The step (2) is prepared by AM gel injection molding technology β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ The method to visualize mechanoluminescent ceramics is as follows: 1) Preparing slurry: adding ceramic precursor powder into a ball mill, placing alumina grinding balls and deionized water into the ball mill, and then adding monomer acrylamide and cross-linking agent N,N'-methylenebisacrylamide, dispersant ammonium citrate and pH adjuster tetramethylammonium hydroxide solution for ball milling to obtain slurry; 2) Preparation of green blank: Wait for the slurry in step 1) to be evenly dispersed by ball milling, pour the slurry into a defoaming tank with a screen, add a catalyst, put it into a vacuum defoaming machine to defoam, add an initiator, stir evenly to avoid introducing bubbles, then inject it into a mold, let it stand and dry in a drying oven to obtain a ceramic green blank, demold it after drying, and put the demolded green blank into a muffle furnace for debinding; 3) Preparation of mechanoluminescent ceramics: The debinded ceramics obtained in step 2) are placed in a vacuum sintering furnace to obtain pure phase ceramics, which are then annealed and polished to obtain β -Ca3(PO4)2:0.20Tb 3+ ,0.10Mn 2+ , x Eu 3+ Visualizing mechanoluminescent ceramics.

7. The method for preparing the visualized mechanoluminescent ceramic according to claim 6, characterized in that: In the step 1), the ceramic precursor powder is added to the ball mill twice, the ball milling time is 2-4 hours, the mass percentage of acrylamide in the ceramic precursor powder is 3-5wt%, the mass percentage of N,N'-methylenebisacrylamide in the ceramic precursor powder is 0.1-0.3wt%, the mass percentage of ammonium citrate in the ceramic precursor powder is 0.01-0.03wt%, the mass percentage of tetramethylammonium hydroxide in the tetramethylammonium hydroxide solution in the ceramic precursor powder is 1.0-1.3wt%, and the solid content of the obtained slurry is 45-55wt%.

8. The method for preparing the visualized mechanoluminescent ceramic according to claim 6, characterized in that: In the step 2), the catalyst is a tetramethylethylenediamine solution, wherein the tetramethylethylenediamine in the tetramethylethylenediamine solution accounts for 20-30wt% of the mass of the ceramic precursor powder; the initiator is an ammonium persulfate solution, wherein the ammonium persulfate in the ammonium persulfate solution accounts for 2-4wt% of the mass of the ceramic precursor powder; the defoaming time in the vacuum defoamer in the step 2) is 30-45min; the drying is carried out in a drying oven at 45°C and 75°C for 20-22h respectively; the specific steps of debinding the biscuit after demolding are: firstly calcining the biscuit at 100-200°C for 5-7h, then cooling to room temperature, with a heating and cooling rate of 0.5-1°C / min; then debinding the biscuit at 450-550°C for 5-7h, then cooling to room temperature, with a heating and cooling rate of 1-2°C / min; finally, debinding the biscuit at 750-850°C for 5-7h, then cooling to room temperature, with a heating and cooling rate of 1-2°C / min.

9. The method for preparing the visualized mechanoluminescent ceramic according to claim 5, characterized in that: The vacuum degree during sintering in step 3) is greater than 5.1×10 -4 Pa, specifically 10 -2 ~10 -4 Pa, the sintering temperature is 1750-1900° C., the sintering time is 9-11 hours, the annealing treatment in step 3) is carried out in an air atmosphere, the annealing temperature is 1350-1450° C., and the annealing time is 3-5 hours.

10. The application of the visualized mechanical luminescent ceramics in the detection of grain machinery and equipment according to claim 1 is characterized in that: Applying it to pressure-sensing ceramics in grain machinery can achieve precise and visual color changes, reflect the stress and strain of the equipment in real time, and optimize the grain machinery.

Images