Integrated photochromic cast ceramic backplane material and preparation method thereof

Abstract

The present invention relates to the field of ceramic backplane technology, and more specifically, to an integrated photochromic cast ceramic backplane material and a preparation method thereof. The chemical formula of the ceramic backplane material is: BaMgSiO4Eu x Fe y , where 0

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic backplanes, and in particular to an integrated photochromic cast ceramic backplane material and a preparation method thereof. Background Art

[0002] In today's smartphone market, the backplane material not only impacts the phone's aesthetics but also directly influences its performance. Currently, mainstream options include glass, metal, or common ceramics. Glass backplanes offer advantages in aesthetics and color rendering, but their fragility and limited strength restrict phone design and durability. While metal backplanes are strong and durable, their monotonous color and signal shielding limit their application in 5G communications and wireless charging technologies. Conventional ceramic backplanes have made some progress in improving their appearance and texture, but their functionality is limited to the surface and fails to fully meet consumers' diverse demands for phone appearance and functionality. To meet consumer demand for personalization and diverse functionality, the development of backplanes with unique properties has become an industry trend.

[0003] Chinese utility model patent CN221381000U discloses a photochromic ceramic plate and mobile phone back cover. The photochromic ceramic plate comprises a support layer and a photochromic layer. The support layer can be any of a ceramic, metal, or glass substrate; the photochromic layer is disposed on the surface of the support layer; and the photochromic layer is formed from a photochromic ceramic. By disposing the photochromic layer on the surface of the support layer, the ceramic, metal, or glass substrate, the photochromic ceramic plate can achieve a photochromic effect, thereby expanding the product range. Research on the photochromic effect and the mechanical properties of the back panel is not included. Summary of the Invention

[0004] The first aspect of the present invention provides an integrated photochromic cast ceramic backplane material, the chemical formula of the ceramic backplane material is: BaMgSiO4Eu x Fe y , where 0 <x≤0.01,0<y≤0.01。

[0005] Optionally, x and y meet the following requirements: 0.002 <x≤0.008,0.002<y≤0.008。

[0006] Optionally, x and y meet the following requirements: 0.004 <x≤0.008,0.002<y≤0.008。

[0007] The raw materials for preparing the ceramic include powders, and the powders include: BaCO3, SiO2, MgO, Eu2O3, and Fe2O3.

[0008] The raw materials for preparing the ceramic also include: solvent, plasticizer, dispersant, binder and defoamer.

[0009] Optionally, the ceramic preparation raw materials include, by weight percentage: 40-60% solvent, 0.5-8% plasticizer, 0.5-5% dispersant, 5-10% binder, 1-5% defoaming agent, and powder makes up the balance.

[0010] Optionally, the solvent includes at least one of toluene, ethyl acetate, ethanol and cyclohexanone.

[0011] Optionally, the solvent includes toluene and ethanol, and the mass ratio of toluene to ethanol is 2-5:1.

[0012] Optionally, the solvent includes toluene and ethanol, and the mass ratio of toluene to ethanol is 2-4:1.

[0013] Optionally, the plasticizer includes at least one of polyethylene glycol, dibutyl phthalate and diethyl sebacate.

[0014] Optionally, the plasticizer includes dibutyl phthalate and polyethylene glycol, and the mass ratio of the dibutyl phthalate to the polyethylene glycol is 1-5:1.

[0015] Optionally, the mass ratio of dibutyl phthalate to polyethylene glycol is 2-4:1.

[0016] Optionally, the dispersant includes at least one of tributyl phosphate, castor oil, and triethanolamine.

[0017] Optionally, the binder includes at least one of polyvinyl butyral and methyl cellulose.

[0018] Optionally, the defoaming agent includes at least one of polydimethylsiloxane and n-butanol.

[0019] The integrated photochromic cast ceramic back panel material has a color change contrast of 55-93% and a Vickers hardness of 570-750 Hv.

[0020] A second aspect of the present invention provides a method for preparing an integrated photochromic cast ceramic backplane material, comprising the following steps:

[0021] S1, weigh the corresponding powder;

[0022] S2, mixing the powders, subjecting them to ball milling, drying, grinding, pre-sintering, and further ball milling to obtain basic ceramic powder;

[0023] S3, mixing the base ceramic powder with a solvent and a dispersant, adding a plasticizer, a binder and a defoaming agent after the initial ball milling, and obtaining a ceramic casting slurry after the secondary ball milling;

[0024] S4, casting the casting slurry using a casting machine to obtain a cast film;

[0025] S5, slicing, punching, and laminating the cast film in sequence to obtain a ceramic body;

[0026] S6, debinding, reduction sintering, cutting and polishing the ceramic body.

[0027] The ball milling is performed according to a mass ratio of powder: zirconium ball: ethanol of 1: (1-2): (1-2).

[0028] Optionally, the ball milling is performed according to a mass ratio of powder: zirconium balls: ethanol of 1:1.5:1.5.

[0029] The pre-sintering treatment in step S2 adopts a direct pre-sintering method.

[0030] Optionally, the pre-sintering temperature is 950-1150° C., the heating rate is 2-8° C. / min, the cooling rate is 4-10° C. / min, and the holding time is 2-5 h.

[0031] Optionally, the pre-sintering temperature is 950-1050° C., the heating rate is 2-5° C. / min, the cooling rate is 4-6° C. / min, and the holding time is 3-5 h.

[0032] Optionally, the pre-sintering temperature is 1000° C., the heating rate is 3° C. / min, the cooling rate is 5° C. / min, and the holding time is 4 h.

[0033] In step S3, the time for the first ball milling is 8 to 14 hours, and the time for the second ball milling is 4 to 8 hours.

[0034] Optionally, the time for the first ball milling in step S3 is 10 to 12 hours, and the time for the second ball milling is 6 to 8 hours.

[0035] The thickness of the cast film in step S4 is 30-60 μm.

[0036] Optionally, the thickness of the cast film in step S4 is 40-50 μm.

[0037] In step S5, the hot pressing temperature is 45-70° C., the hot pressing pressure is 10-30 MPa, the cold isostatic pressing pressure is 150-250 MPa, and the holding time is 5-30 min.

[0038] Optionally, in step S5, the hot pressing temperature is 50-65° C., the hot pressing pressure is 10-20 MPa, the cold isostatic pressing pressure is 180-200 MPa, and the holding time is 10-20 min.

[0039] Optionally, the dimensions of the ceramic blank are 12-20 cm in length, 5-10 cm in width, and 15-40 mm in thickness.

[0040] The dimensions of the ceramic blank are 13-15 cm in length, 6-8 cm in width, and 20-35 mm in thickness.

[0041] In step S6, the temperature for degreasing is 550-650 °C, the heating rate is 0.5-3 °C / min, and the heat preservation time is 5-8 h.

[0042] Optionally, the temperature for degreasing is 550-600 °C, the heating rate is 0.5-1 °C / min, and the heat preservation time is 5-^ h.

[0043] In step S6, the reduction sintering temperature is 1300-1450 °C, the heating rate is 2-8 °C / min, the cooling rate is 4-10 °C / min, and the heat preservation time is 2-4 h.

[0044] [[ID=!5]]Optionally, the sintering temperature is 1300-1350 °C, the heating rate is 3-5 °C / min, the cooling rate is 4-6 °C / min, and the heat preservation time is 2-4 h.

[0045] The reducing atmosphere includes H2 and N2.

[0046] By volume ratio, the reducing atmosphere contains 3-8% of H2.

[0047] Optionally, by volume ratio, the reducing atmosphere contains 4-6% of H2.

[0048] The applicant's research found that the chemical formula of the ceramic backplane material is: BaMgSiO4Eu x Fe y , where 0 < x ≤ 0.01, 0 < y ≤ 0.01. The co-doping of rare earth element Eu and transition metal element Fe significantly improves the color change contrast and hardness of the ceramic. It is possible that Fe can form a composite structure with Eu, introduce vacancy-related defects, increase the trap concentration and depth, thereby enhancing the light absorption ability, promoting the transfer and capture of electrons, and thus improving the efficiency of photochromism. At the same time, the doping of Fe can also improve the hardness and stability of the material, making it not prone to structural damage during the photochromic process. The doping of Eu can introduce oxygen vacancies, and these oxygen vacancies serve as electron capture centers. When ultraviolet light is absorbed, electrons are excited and enter the oxygen vacancies, forming color centers, thereby causing color changes.

[0049] Beneficial effects

[0050] 1. The chemical formula of the ceramic backplane material is: BaMgSiO4Eu x Fe y, where \(0 < x \leq 0.01\) and \(0 < y \leq 0.01\). The co-doping of rare earth element Eu and transition metal element Fe significantly improves the color change contrast and hardness of the ceramic.

[0051] 2. The \(x\) and \(y\) satisfy the following requirements: \(0.002 < x \leq 0.008\) and \(0.002 < y \leq 0.008\), which can further improve the color change contrast and hardness of the ceramic backplane material, making the color change contrast \(> 90\%\) and the Vickers hardness \(> 600\) Hv.

[0052] 3. The response time of the photochromic tape-casted ceramic backplane material prepared in this application is \(< 8\) s, with high color change fatigue resistance and good chemical stability.

[0053] 4. Through a specific tape-casting preparation method, the ceramic material prepared in this application has a simple composition and low economic cost. It combines the functions of structural support and photochromism, can meet the preparation of large-size ceramics, and broadens the application scope of ceramics.

[0054] 5. The ceramic backplane material prepared in this application helps to achieve large-scale production operations, can be used in the field of mobile phone backplanes, and broadens the application scenarios of photochromic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 XRD patterns of the ceramic backplane materials of the examples and comparative examples, where JCPDS 16 - 0573 is the spectrum of the barium magnesium silicate standard card.

[0056] Figure 2 Diffuse reflection spectra of Example 1 before irradiation and after irradiation with 365 nm ultraviolet light and sunlight.

[0057] Figure 3 Diffuse reflection spectra of Example 2 before irradiation and after irradiation with 365 nm ultraviolet light and sunlight.

[0058] Figure 4 Diffuse reflection spectra of Example 3 before irradiation and after irradiation with 365 nm ultraviolet light and sunlight. [[ID=?]]

[0059] Figure 5 Diffuse reflection spectra of Comparative Example 1 before irradiation and after irradiation with 365 nm ultraviolet light and sunlight.

[0060] Figure 6 Diffuse reflection spectra of Comparative Example 2 before irradiation and after irradiation with 365 nm ultraviolet light and sunlight.

[0061] Figure 7 Schematic diagrams of the backplane of different sizes before and after color change provided by Example 1, where a is before color change and b is after color change.

[0062] Figure 8 It should be noted that there is a question mark in the original text where the tag should be, which might be an error. The translation is provided based on the best understanding of the context.It is a summary diagram of the color change contrast and response time of the embodiments and comparative examples. DETAILED DESCRIPTION

[0063] Example 1

[0064] An integrated photochromic cast ceramic backplane material, the chemical formula of the ceramic backplane material is: BaMgSiO4Eu x Fe y , where x=0.005, y=0.005.

[0065] The ceramic preparation raw materials, by weight percentage, are: 42% solvent (toluene:ethanol in a 3:1 weight ratio), 5% plasticizer (polyethylene glycol:dibutyl phthalate in a 3:1 weight ratio), 3% dispersant (tributyl phosphate), 7.5% binder (polyvinyl butyral, Sinopharm Chemical Reagent Co., Ltd.), 2.4% defoamer (n-butanol), with powder making up the balance. Polyethylene glycol: Shanghai trial, Sinopharm Chemical Reagent Co., Ltd.

[0066] The powders are: BaCO3, SiO2, MgO, Eu2O3 and Fe2O3.

[0067] The molar ratio of BaCO3, SiO2, MgO, Eu2O3 and Fe2O3 is 0.995:1:0.995:0.0025:0.0025.

[0068] A method for preparing an integrated photochromic cast ceramic backplane material comprises the following steps:

[0069] S1, weighing the corresponding powder according to the stoichiometric ratio of each element in the chemical formula of the ceramic backplane material;

[0070] S2, the powder is mixed by wet high-energy ball milling, according to the mass ratio of powder: zirconium ball: ethanol 1:1.5:1.5, the mixing time is 24 hours, and the components are fully mixed; after drying and grinding, it is passed through a 60-mesh sieve, placed in a crucible and compacted, and then directly pre-fired by a specific method, with a pre-fire temperature of 1000°C, a heating rate of 3°C / min, a holding time of 4 hours, a cooling rate of 5°C / min, and cooling to room temperature to obtain a basic ceramic powder;

[0071] S3, weighing the base ceramic powder, solvent and dispersant in proportion, ball-milling for 12 hours to mix the slurry, then adding plasticizer, binder and defoamer in proportion to the initially ball-milled slurry, ball-milling for 6 hours to mix the slurry again, to obtain a uniform and stable ceramic tape casting slurry;

[0072] S4, casting the prepared casting slurry into a casting film with a thickness of 40 μm using a casting machine;

[0073] S5, the cast film is cut into 14×7 cm sheets and perforated. First, 60 layers of cast film are hot-pressed and bonded into a sheet of fixed size at 55°C and 20 MPa. The sheet is then vacuum-sealed and cold isostatically pressed at 200 MPa for 15 minutes to form a ceramic body.

[0074] S6, the green body is placed in a muffle furnace for debinding at a heating rate of 0.5℃ / min, a holding time of 6h, and a debinding temperature of 600℃; after debinding, reduction sintering is carried out. The specific method is to use a tubular furnace at a sintering temperature of 1350℃, a heating rate of 4℃ / min, a holding time of 3h, a cooling rate of 5℃ / min, and sintering in a reducing atmosphere (volume ratio, 3% H2, 97% N2), and then cut and polished according to the required size.

[0075] Example 2:

[0076] An integrated photochromic cast ceramic backplane material, the chemical formula of the ceramic backplane material is: BaMgSiO4Eu x Fe y , where x=0.005, y=0.0025.

[0077] Calculated by weight percentage, the raw materials for preparing the ceramic are: 45% solvent (toluene: ethanol weight ratio is 3:1), 5% plasticizer (polyethylene glycol: dibutyl phthalate weight ratio is 3:1), 3% dispersant (tributyl phosphate), 7.5% binder (polyvinyl butyral), 2.4% defoaming agent (n-butanol), and the balance is made up of powder.

[0078] The powders are: BaCO3, SiO2, MgO, Eu2O3 and Fe2O3.

[0079] The molar ratio of BaCO3, SiO2, MgO, Eu2O3 and Fe2O3 is 0.995:1:0.9975:0.0025:0.00125.

[0080] A method for preparing an integrated photochromic cast ceramic backplane material comprises the following steps:

[0081] S1, weighing the corresponding powder according to the stoichiometric ratio of each element in the chemical formula of the ceramic backplane material;

[0082] S2, the powder is mixed by wet high-energy ball milling, according to the mass ratio of powder: zirconium ball: ethanol 1:1.5:1.5, the mixing time is 24 hours, and the components are fully mixed; after drying and grinding, it is passed through a 60-mesh sieve, placed in a crucible and compacted, and then directly pre-fired by a specific method, with a pre-fire temperature of 1000°C, a heating rate of 3°C / min, a holding time of 4 hours, a cooling rate of 5°C / min, and cooling to room temperature to obtain a basic ceramic powder;

[0083] S3, weighing the base ceramic powder, solvent and dispersant in proportion, ball-milling for 12 hours to mix the slurry, then adding plasticizer, binder and defoamer in proportion to the initially ball-milled slurry, ball-milling for 6 hours to mix the slurry again, to obtain a uniform and stable ceramic tape casting slurry;

[0084] S4, casting the prepared casting slurry into a casting film with a thickness of 45 μm using a casting machine;

[0085] S5, the cast film is cut into 14×7 cm sheets and perforated. First, 60 layers of cast film are hot-pressed and bonded into a sheet of fixed size at 55°C and 20 MPa. The sheet is then vacuum-sealed and cold isostatically pressed at 200 MPa for 15 minutes to form a ceramic body.

[0086] S6, the green body is placed in a muffle furnace for debinding at a heating rate of 0.5℃ / min, a holding time of 6h, and a debinding temperature of 550℃; after debinding, reduction sintering is carried out. The specific method is to use a tubular furnace at a sintering temperature of 1300℃, a heating rate of 4℃ / min, a holding time of 3h, a cooling rate of 5℃ / min, and sintering in a reducing atmosphere (volume ratio, 3% H2, 97% N2), and then cut and polished according to the required size.

[0087] Example 3:

[0088] An integrated photochromic cast ceramic backplane material, the chemical formula of the ceramic backplane material is: BaMgSiO4Eu x Fe y , where x=0.005, y=0.0075.

[0089] Calculated by weight percentage, the raw materials for preparing the ceramic are: 45% solvent (toluene: ethanol weight ratio is 3:1), 5% plasticizer (polyethylene glycol: dibutyl phthalate weight ratio is 3:1), 3% dispersant (tributyl phosphate), 7.5% binder (polyvinyl butyral), 2.4% defoaming agent (n-butanol), and the balance is made up of powder.

[0090] The powders are: BaCO3, SiO2, MgO, Eu2O3 and Fe2O3.

[0091] The molar ratio of BaCO3, PSiO2, MgO, Eu2O3 and Fe2O3 is 0.995:1:0.9925:0.0025:0.00375.

[0092] A method for preparing an integrated photochromic cast ceramic backplane material comprises the following steps:

[0093] S1, weighing the corresponding powder according to the stoichiometric ratio of each element in the chemical formula of the ceramic backplane material;

[0094] S2, the powder is mixed by wet high-energy ball milling, according to the mass ratio of powder: zirconium ball: ethanol 1:1.5:1.5, the mixing time is 24 hours, and the components are fully mixed; after drying and grinding, it is passed through a 60-mesh sieve, placed in a crucible and compacted, and then directly pre-fired by a specific method, with a pre-fire temperature of 1000°C, a heating rate of 3°C / min, a holding time of 4 hours, a cooling rate of 5°C / min, and cooling to room temperature to obtain a basic ceramic powder;

[0095] S3, weighing the base ceramic powder, solvent and dispersant in proportion, ball-milling for 12 hours to mix the slurry, then adding plasticizer, binder and defoamer in proportion to the initially ball-milled slurry, ball-milling for 6 hours to mix the slurry again, to obtain a uniform and stable ceramic tape casting slurry;

[0096] S4, casting the prepared casting slurry into a casting film with a thickness of 40 μm using a casting machine;

[0097] S5, the cast film is cut into 14×7 cm sheets and perforated. First, 60 layers of cast film are hot-pressed and bonded into a sheet of fixed size at 50°C and 20 MPa. The sheet is then vacuum-sealed and cold isostatically pressed at 200 MPa for 15 minutes to form a ceramic body.

[0098] In step S6, the green body is placed in a muffle furnace for debinding at a heating rate of 0.5°C / min, a holding time of 6 hours, and a binder removal temperature of 600°C. After debinding, reduction sintering is performed in a tubular furnace at a sintering temperature of 1350°C, a heating rate of 4°C / min, a holding time of 3 hours, and a cooling rate of 5°C / min in a reducing atmosphere (volume ratio, 3% H2, 97% N2). The green body is then cut and polished to the desired size.

[0099] Comparative Example 1:

[0100] An integrated photochromic cast ceramic backplane material, the chemical formula of the ceramic backplane material is: BaMgSiO4Eu x , where x=0.005.

[0101] Calculated by weight percentage, the raw materials for preparing the ceramic are: 45% solvent (toluene: ethanol weight ratio is 3:1), 5% plasticizer (polyethylene glycol: dibutyl phthalate weight ratio is 3:1), 3% dispersant (tributyl phosphate), 7.5% binder (polyvinyl butyral), 2.4% defoaming agent (n-butanol), and the balance is made up of powder.

[0102] The powders are: BaCO3, SiO2, MgO and Eu2O3.

[0103] The molar ratio of BaCO3, SiO2, MgO and Eu2O3 is 0.99:1:1:0.005.

[0104] A method for preparing an integrated photochromic cast ceramic backplane material comprises the following steps:

[0105] S1, weighing the corresponding powder according to the stoichiometric ratio of each element in the chemical formula of the ceramic backplane material;

[0106] S2, the powder is mixed by wet high-energy ball milling, with the mass ratio of powder: zirconium ball: ethanol being 1:1.5:1.5, and the mixing time being 24 hours, and all components are fully mixed; after drying and grinding, the powder is passed through a 60-mesh sieve, placed in a crucible and compacted, and then directly pre-fired by a specific method, with a pre-firing temperature of 1000°C, a heating rate of 3°C / min, a holding time of 4 hours, and a cooling rate of 5°C / min to obtain a basic ceramic powder;

[0107] S3, weighing the base ceramic powder, solvent and dispersant in proportion, ball-milling for 12 hours to mix the slurry, then adding plasticizer, binder and defoamer in proportion to the initially ball-milled slurry, ball-milling for 6 hours to mix the slurry again, to obtain a uniform and stable ceramic tape casting slurry;

[0108] S4, casting the prepared casting slurry into a casting film with a thickness of 45 μm using a casting machine;

[0109] S5, the cast film is cut into 14×7 cm sheets and perforated. First, 60 layers of cast film are hot-pressed and bonded into a sheet of fixed size at 55°C and 20 MPa. The sheet is then vacuum-sealed and cold isostatically pressed at 200 MPa for 15 minutes to form a ceramic body.

[0110] In step S6, the green body is placed in a muffle furnace for debinding at a heating rate of 0.5°C / min, a holding time of 6 hours, and a debinding temperature of 600°C. After debinding, reduction sintering is performed in a tubular furnace at a sintering temperature of 1300°C, a heating rate of 3°C / min, a holding time of 2 hours, a cooling rate of 5°C / min, and a reducing atmosphere of 5% H2 and 95% N2. The green body is then cut and polished to the required size.

[0111] Comparative Example 2

[0112] An integrated photochromic cast ceramic backboard material, the chemical formula of the ceramic backboard material is: BaMgSiO4Fe x , where x=0.005.

[0113] Calculated by weight percentage, the raw materials for preparing the ceramic are: 45% solvent (toluene: ethanol weight ratio is 3:1), 5% plasticizer (polyethylene glycol: dibutyl phthalate weight ratio is 3:1), 3% dispersant (tributyl phosphate), 7.5% binder (polyvinyl butyral), 2.4% defoaming agent (n-butanol), and the balance is made up of powder.

[0114] The powders are: BaCO3, SiO2, MgO and Fe2O3.

[0115] The molar ratio of BaCO3, SiO2, MgO and Fe2O3 is 0.99:1:1:0.005.

[0116] A method for preparing an integrated photochromic cast ceramic backplane material comprises the following steps:

[0117] S1, weighing the corresponding powder according to the stoichiometric ratio of each element in the chemical formula of the ceramic backplane material;

[0118] S2, the powder is mixed by wet high-energy ball milling, with the mass ratio of powder: zirconium ball: ethanol being 1:1.5:1.5, and the mixing time being 24 hours, and all components are fully mixed; after drying and grinding, the powder is passed through a 60-mesh sieve, placed in a crucible and compacted, and then directly pre-fired by a specific method, with a pre-firing temperature of 1000°C, a heating rate of 3°C / min, a holding time of 4 hours, and a cooling rate of 5°C / min to obtain a basic ceramic powder;

[0119] S3, weighing the base ceramic powder, solvent and dispersant in proportion, ball-milling for 12 hours to mix the slurry, then adding plasticizer, binder and defoamer in proportion to the initially ball-milled slurry, ball-milling for 6 hours to mix the slurry again, to obtain a uniform and stable ceramic tape casting slurry;

[0120] S4, casting the prepared casting slurry into a casting film with a thickness of 45 μm using a casting machine;

[0121] S5, the cast film is cut into 14×7 cm sheets and perforated. First, 60 layers of cast film are hot-pressed and bonded into a sheet of fixed size at 55°C and 20 MPa. The sheet is then vacuum-sealed and cold isostatically pressed at 200 MPa for 15 minutes to form a ceramic body.

[0122] In step S6, the green body is placed in a muffle furnace for debinding at a heating rate of 0.5°C / min, a holding time of 6 hours, and a debinding temperature of 600°C. After debinding, reduction sintering is performed in a tubular furnace at a sintering temperature of 1300°C, a heating rate of 3°C / min, a holding time of 2 hours, a cooling rate of 5°C / min, and a reducing atmosphere of 5% H2 and 95% N2. The green body is then cut and polished to the required size.

[0123] Performance testing methods and data

[0124] The photochromic cast ceramic backplane materials prepared in the examples and comparative examples were subjected to the following performance tests, and the test data are listed in Table 1.

[0125] 1) Phase structure test: Use X-ray diffractometer to analyze the crystal structure and phase composition of the prepared ceramic backplane. Figure 1 The XRD spectrum of the prepared backplane is basically consistent with the standard card of barium magnesium silicate. Since the content of Fe and Eu doping is very small, they are dissolved into the crystal lattice, so there is no obvious difference in the XRD between the embodiment and the comparative example.

[0126] 2) Hardness test: Use a Vickers hardness tester to perform a hardness test on the prepared ceramic backplane material.

[0127] 3) Photochromic performance test:

[0128] The photochromic cast ceramic backplane material of the present application changes from its original milky white to pink when exposed to ultraviolet light in the wavelength range of 255-365nm; when exposed to green light of 520-550nm or heated at 200°C, the ceramic returns to its original color.

[0129] Contrast test: Use UV-visible near-infrared spectrophotometer to test the change in diffuse reflectance R% of the back panel before and after irradiation with 365nm light source, and calculate the color change contrast, such as Figure 2-4 It shows that the ceramic backplane materials prepared in Examples 2-4 have a higher contrast ratio. Figure 5 、 6 It is shown that the contrast ratio of the ceramic backplane materials prepared in Comparative Examples 1 and 2 is significantly lower than that of Examples 1-3.

[0130] Response time test: record the time required to reach the maximum color change and maximum contrast. Figure 7 There is a clear difference in the color of the ceramic back panel material before and after it changes color.

[0131] like Figure 8 As shown, there are obvious differences in the photochromic performance tests of Examples 1-3 and Comparative Examples 1 and 2, which indicates that the raw material composition of the ceramic backplane material has a significant impact on the photochromic performance.

[0132] Table 1

[0133] Vickers hardness (Hv) Contrast (%) Response time (s) Comparative Example 1 570 55.7 10.2 Comparative Example 2 610 77.7 8.8 Example 1 750 92.2 5.4 Example 2 680 90.3 6.2 Example 3 690 90.2 7.6

[0134] It can be seen from the data in Table 1 that the ceramic backplane materials prepared in Examples 1-3 have high hardness, good wear resistance and scratch resistance, contrast ratio > 90%, response time < 8s, high color change fatigue resistance, and good chemical stability.

Claims

1. An integrated photochromic cast ceramic backplane material, characterized in that: The chemical formula of the ceramic back plate material is: BaMgSiO4Eu x Fe y , where x and y meet the following requirements: 0.002 <x≤0.008,0.002<y≤0.008; The raw materials for preparing the ceramic back plate material include powders, and the powders include BaCO3, SiO2, MgO, Eu2O3 and Fe2O3; The raw materials for preparing the ceramic back plate material also include solvent, plasticizer, dispersant, binder and defoamer; The preparation method of the integrated photochromic cast ceramic backplane material comprises the following steps: weighing corresponding powders; mixing the powders, subjecting them to ball milling, drying, grinding, pre-sintering, and further ball milling to obtain basic ceramic powder; mixing the basic ceramic powder with a solvent and a dispersant, adding a plasticizer, a binder, and a defoaming agent after the initial ball milling, and performing a secondary ball milling to obtain a ceramic cast slurry; casting the cast slurry using a casting machine to obtain a cast film; slicing, punching, and laminating the cast film in sequence to obtain a ceramic green body; and debinding, reduction sintering, and cutting and polishing the ceramic green body.

2. The integrated photochromic cast ceramic backplane material according to claim 1, characterized in that: The pre-sintering temperature is 950-1150° C., the heating rate is 2-8° C. / min, the cooling rate is 4-10° C. / min, and the holding time is 2-5 hours.

3. The integrated photochromic cast ceramic backplane material according to claim 2, characterized in that: The debinding temperature is 550-650° C., the heating rate is 0.5-3° C. / min, and the holding time is 5-8 hours.

4. The integrated photochromic cast ceramic backplane material according to claim 3, characterized in that: The reduction sintering temperature is 1300-1450° C., the heating rate is 2-8° C. / min, the cooling rate is 4-10° C. / min, and the holding time is 2-4 hours.

5. The integrated photochromic cast ceramic backplane material according to claim 4, characterized in that: The lamination includes hot pressing and cold isostatic pressing in sequence.

6. The integrated photochromic cast ceramic backplane material according to claim 5, characterized in that: The temperature of the hot pressing is 50-65° C. and the pressure is 10-20 MPa; the pressure of the cold isostatic pressing is 180-200 MPa and the holding time is 10-20 min.

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