Ceramic stack sculpture blending agent, preparation method thereof and product forming and sintering method

Abstract

The present application relates to the technical field of inorganic non-metallic materials, and discloses a ceramic stack sculpture blending agent, a preparation method thereof and a product forming and sintering method, wherein the ceramic stack sculpture blending agent comprises the following components in percentage by mass: a zinc oxide modified zirconium silicate matrix 15-25%, a nano-composite reinforcing agent 8-12%, a gradient melting adjusting agent 30.5-41.2%, a light transmission optimizing agent 10.3-15.8%, and a rare earth stabilizer 3-5%. The preparation method comprises pretreatment activation, wet ball milling, spray drying and compound aging. The sintering method comprises clay blending, layered stack forming and gradient sintering. The present application breaks through the technical bottleneck that the light transmission, strength and forming precision are difficult to be considered in the traditional process, significantly improves the folding strength, high-temperature stability and complex relief detail restoration capacity of the stack sculpture product, and is suitable for the industrialized production of precise optical ceramic devices and artistic reliefs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inorganic non-metallic materials, in particular to a ceramic stack sculpture blending agent, a preparation method thereof and a product forming and sintering method. BACKGROUND

[0002] Traditional zirconium silicate-based ceramic materials generally have crack defects caused by thermal expansion mismatch at the interface between the base and the stack sculpture layer in high-temperature stack sculpture processes, which seriously affects the structural integrity and service life of the relief product.

[0003] Although the use of a single nano-enhancing agent or a melting adjusting agent in the prior art can partially improve the mechanical properties, it is difficult to take into account the light transmittance, high-temperature stability and forming precision of complex shapes. For example, excessive addition of the enhancing agent can easily cause agglomeration of nano-particles, resulting in uneven dispersion of the slurry and micro-cracks and pores after sintering; and the method of relying solely on high-temperature sintering to adjust the thermal expansion coefficient is prone to cause a sharp drop in light transmittance due to excessive precipitation of the glass phase.

[0004] In addition, traditional transparent ceramics often need to sacrifice process efficiency to achieve a balance between light transmittance and strength, and thus use multi-step coating or ultra-fine powder pretreatment, resulting in a substantial increase in production cost.

[0005] The above technical bottlenecks have seriously restricted the large-scale application of high-precision ceramic stack sculpture products in the fields of optical devices and artistic reliefs. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a ceramic stack sculpture blending agent, a preparation method thereof and a product forming and sintering method, which solve the technical problem that traditional zirconium silicate-based ceramics crack in high-temperature stack sculpture due to thermal expansion mismatch at the interface and the light transmittance and mechanical properties are difficult to improve simultaneously.

[0007] To achieve the above object, the present application is implemented by the following technical solutions:

[0008] The present application provides a ceramic stack sculpture blending agent, which comprises the following components in terms of mass percentage: 15-25% of a zinc oxide modified zirconium silicate base, 8-12% of a nano-composite reinforcing agent, 30.5-41.2% of a gradient melting adjusting agent, 10.3-15.8% of a light transmittance optimizing agent and 3-5% of a rare earth stabilizing agent.

[0009] The composition of each component and the synergistic effect are as follows:

[0010] Zinc oxide modified zirconium silicate base:

[0011] As a bonding phase, the ZnO-ZrSiO4 composite phase is formed by the solid-phase reaction (reaction temperature 1250-1300℃) of ZnO and zirconium silicate, which provides a stable skeleton structure at high temperatures.

[0012] Preferably, the zinc oxide modified zirconium silicate matrix is formed by high-temperature solid-phase reaction of zirconium silicate (ZrSiO4) and zinc oxide (ZnO), wherein zinc oxide accounts for 20% of the mass of the matrix.

[0013] Nano-composite reinforcing agent:

[0014] Preferably, the nano-composite reinforcing agent contains nano-titanium dioxide (TiO2, particle size 20-50 nm) and nano-aluminum oxide (Al2O3, particle size 30-80 nm), wherein the molar ratio of TiO2 to Al2O3 is 2.0:1-3.0:1.

[0015] Nano-TiO2 and Al2O3 are chemically bonded through surface hydroxyl groups (-OH) and Al-OH bonds of clay minerals in the body, forming a three-dimensional network reinforcing framework at the stack sculpture part and inhibiting plastic deformation.

[0016] Gradient melting regulator:

[0017] Preferably, the gradient melting regulator is composed of spodumene (LiAlSi2O6), quartz (SiO2), and zinc borate (ZnO·B2O3), wherein the mass ratio of spodumene to quartz is 1.41:1-1.5:1, and zinc borate accounts for 0.5%-1.2% of the mass of the regulator.

[0018] Spodumene (melting point 1423°C) and quartz (melting point 1713°C) are melted in stages to form a glass phase with gradually changing viscosity, which bridges the Si-O-Si network of the body clay and realizes gradient matching of the coefficient of thermal expansion.

[0019] Zinc borate generates [BO3] 3- coordination structure during melting, further buffering the interfacial stress.

[0020] Light transmission optimizer:

[0021] Preferably, the light transmission optimizer is composed of potassium feldspar (KAlSi3O8) and sodium feldspar (NaAlSi3O8) in a 1:1 mass ratio, and 0.4%-0.8% of calcium phosphate (Ca3(PO4)2) is added to the mass of the optimizer.

[0022] The alkali metal ions (K + , Na + ) of potassium / sodium feldspar reduce the viscosity of the glass phase and promote light penetration; calcium phosphate as a mineralizer regulates the growth direction of microcrystals.

[0023] Rare earth stabilizer:

[0024] Preferably, the rare earth stabilizer comprises yttrium oxide (Y2O3) and zinc oxide (ZnO), wherein Y2O3 accounts for 80% to 90% of the mass of the stabilizer, and the molar ratio of Y2O3 to ZnO is 1.44:1 to 3.24:1.

[0025] Yttrium oxide and zinc oxide are coordinated through oxygen vacancies, which reduces the nucleation energy barrier of the glaze layer, induces the precipitation of YPO4 microcrystals with a size of 80 to 200 nm, and reduces light scattering loss.

[0026] Preferably, the preparation method of the zinc oxide modified zirconium silicate matrix comprises the following steps:

[0027] (1) Zirconium silicate (ZrSiO4, purity ≥ 99.5%) and zinc oxide (ZnO, particle size D50 = 1.0 to 2.5 μm) are weighed and mixed in a mass ratio of 4:1;

[0028] (2) The mixed powder is placed in a high-temperature furnace and heated to 1250 to 1300°C at a rate of 5 to 10°C / min, and held for 1.5 to 2.5 hours for solid-phase reaction;

[0029] (3) After cooling to room temperature, zirconia milling beads (particle size 0.5 to 1.0 mm) are added, and wet ball milling is performed at a ball-to-material ratio of 5:1 to 8:1 for 3 to 5 hours, with a slurry particle size D50 = 5 to 10 μm;

[0030] (4) Spray drying to obtain zinc oxide modified zirconium silicate matrix powder with a water content of ≤0.5%.

[0031] Preferably, the preparation method of the nanocomposite reinforcing agent comprises the following steps:

[0032] (1) Nanometer TiO2 (particle size 20 to 50 nm) and Al2O3 (particle size 30 to 80 nm) are weighed in a molar ratio of 2.0:1 to 3.0:1;

[0033] (2) The mixed powder is soaked in a 5.0 vol% nitric acid solution and ultrasonically treated (frequency 40 kHz, power 200 W) for 2 to 2.5 hours;

[0034] (3) Wash with a centrifuge at a speed of 4000 to 5000 rpm until the pH of the filtrate is 6.5 to 7.0;

[0035] (4) Vacuum drying at 60 to 80°C for 12 to 24 hours, and passing through a 325 mesh sieve for use.

[0036] Preferably, the preparation method of the gradient melting regulator comprises the following steps:

[0037] (1) Spodumene (LiAlSi2O6, K2O+Na2O≤0.5%) and quartz (SiO2, α phase content≥95%) are respectively crushed to D90≤50μm;

[0038] (2) Spodumene and quartz are weighed according to the mass ratio of 1.41:1-1.5:1, and 0.5%-1.2% zinc borate (ZnO·B2O3) is added;

[0039] (3) Dry mixing in a three-dimensional mixer at a speed of 10-15rpm for 25-35 minutes;

[0040] (4) Passing through a 200-mesh screen and sealing for storage.

[0041] Preferably, the preparation method of the light transmission optimization agent comprises the following steps:

[0042] (1) Potassium feldspar (KAlSi3O8, K2O≥10.5%) and sodium feldspar (NaAlSi3O8, Na2O≥7.0%) are mixed according to a mass ratio of 1:1;

[0043] (2) Calcium phosphate (Ca3(PO4)2, P2O5≥40%) is added in an amount of 0.4%-0.8% of the total mass of the optimization agent;

[0044] (3) Wet ball milling for 2-4 hours (medium is alumina ball with a particle size of 2-5mm, and the slurry particle size D50=2-5μm);

[0045] (4) After drying, passing through a 325-mesh screen to obtain light transmission optimization agent powder.

[0046] Preferably, the preparation method of the rare earth stabilizer comprises the following steps:

[0047] (1) Yttrium oxide (Y2O3, purity≥99.9%) and zinc oxide (ZnO, particle size≤5μm) are weighed according to a mass ratio of 4:1-9:1;

[0048] (2) Deionized water is added (solid-liquid ratio 1:1-1:2), and zirconium oxide beads (particle size 0.3-0.5mm) are used for ball milling for 4-6 hours;

[0049] (3) After the slurry is dried at 100-120℃, it is crushed and passed through a 325-mesh screen;

[0050] (4) The molar ratio of Y2O3 to ZnO is controlled to be 1.44:1-3.24:1.

[0051] The second aspect of the present application provides a preparation method of the ceramic stack sculpture blending agent, comprising the following steps:

[0052] Step 1: Pretreatment and raw material activation

[0053] 1. Lithium feldspar / quartz pretreatment:

[0054] Lithium feldspar and quartz are ground separately to D90≤50μm;

[0055] Lithium feldspar and quartz are mixed in a mass ratio of 1.41:1 to 1.5:1, and 0.5% to 1.2% of zinc borate is added to the total amount of the adjusting agent, and dry mixing is performed in a three-dimensional mixer at a speed of 10 to 15 rpm for 25 to 35 minutes.

[0056] 2. Nano-composite reinforcing agent activation:

[0057] The nano TiO2 / Al2O3 composite powder is soaked in 5.0vol% nitric acid solution for 2 to 2.5 hours, and ultrasonic treatment (frequency 40 kHz, power 200 W) is performed for 2 hours;

[0058] Centrifugal washing (speed 4000 to 5000 rpm) is performed until the filtrate pH is 6.5 to 7.0, and drying is performed at 60 to 80°C for standby use.

[0059] Step 2: Mixing the zinc oxide modified zirconium silicate matrix, nano-composite reinforcing agent, and gradient melting adjusting agent with a solvent for wet ball milling

[0060] 1. Ball milling medium and parameters:

[0061] Zirconium oxide bead size: 0.3 to 0.5 mm;

[0062] Ball-to-material ratio (grinding beads: raw material): (8:1) to (10:1) (mass ratio);

[0063] Solvent: deionized water and ethanol in a volume ratio of 2:1 to 3:1;

[0064] Speed: 280 to 320 rpm;

[0065] Time: 5 to 7 hours.

[0066] 2. Slurry properties:

[0067] Particle size distribution: D50=0.6 to 1.0μm;

[0068] Zeta potential absolute value > 35mV (to avoid secondary agglomeration of nanoparticles).

[0069] Step 3: Spray drying granulation

[0070] 1. Drying parameters:

[0071] Inlet temperature: 175 to 185°C;

[0072] Outlet temperature: 80 to 90°C;

[0073] Atomization pressure: 0.15-0.25 MPa.

[0074] 2. Powder index:

[0075] Moisture content: 1.2%-1.8%;

[0076] Loose bulk density: 0.45-0.55 g / cm 3 ;

[0077] Particle size D50=0.8-1.2 μm.

[0078] Step 4: Functional agent compounding and aging

[0079] 1. Mixing process:

[0080] Optical transmission optimizer and rare earth stabilizer are respectively passed through a 325 mesh sieve;

[0081] According to the component ratio, the spray-dried powder is mixed in a V-type mixer for 50-70 minutes (rotation speed 10-12 rpm).

[0082] 2. Aging treatment:

[0083] Sealed storage temperature: 20-25℃;

[0084] Aging time: 22-26 hours.

[0085] The third aspect of the present application provides a forming and sintering method of a ceramic stack sculpture product, comprising the following steps:

[0086] Step 1: clay blending

[0087] 1. Blending agent addition ratio:

[0088] The ceramic stack blending agent is added at 3.0%-8.0% of the total mass of the blank.

[0089] 2. Vacuum pugging process:

[0090] Vacuum degree: -0.092 to -0.098 MPa;

[0091] Pugging times: 2-3 times;

[0092] Moisture content of the clay: 18.0%-22.0%.

[0093] Step 2: layered stack forming

[0094] 1. Base clay pressing:

[0095] The base clay without adding blending agent is pressed into a shape with a thickness of 2.0-3.0 mm as the bottom layer.

[0096] 2. Stack layer forming:

[0097] Superimpose the slurry containing the harmonizing agent on the surface of the bottom layer, form the stack layer by engraving or mechanical extrusion, and the thickness is 0.2-1.0 mm.

[0098] 3. Drying control:

[0099] Ambient humidity: 45%-55%;

[0100] Final moisture content of drying: ≤1.0%.

[0101] Step 3: Gradient firing system

[0102] 1. Temperature rising stage:

[0103] First stage: temperature rising to 600℃ at a rate of 20-25℃ / min, and holding for 25-35 minutes;

[0104] Second stage: temperature rising to 950℃ at a rate of 4-6℃ / min, and holding for 50-70 minutes;

[0105] Third stage: temperature rising to 1280-1350℃ at a rate of 2-4℃ / min, and holding for 1.5-2.5 hours.

[0106] 2. Cooling stage:

[0107] Temperature falling rate above 800℃: ≤2℃ / min;

[0108] Natural cooling below 800℃.

[0109] 3. Firing atmosphere:

[0110] Oxygen concentration: 18.0-21.0 vol%;

[0111] Kiln pressure control: -5 to +5 Pa.

[0112] The application provides a ceramic stack sculpture harmonizing agent, a preparation method thereof and a product forming and firing method. The application has the following beneficial effects:

[0113] 1. The application strengthens the crystal boundary bonding force and the pore filling effect through the complex phase formation mechanism of zinc oxide and zirconium silicate, so that the ceramic matrix can still maintain high strength and thermal stability in a high temperature environment of 1250-1400℃, and the technical problem of easy interface peeling of the traditional zirconium silicate matrix in the high temperature stack sculpture process is completely solved.

[0114] 2. Based on the nano network skeleton construction technology optimized based on the TiO2 / Al2O3 molar ratio, the surface active site is directionally bonded to inhibit the agglomeration of nanoparticles, and the normal temperature mechanical properties and forming size precision of the stack layer are simultaneously improved, so as to guarantee the detail restoration degree of complex relief patterns.

[0115] 3、The gradient melting regulator of the present application forms a transition glass phase with gradually changed viscosity by staged melting, buffers the thermal expansion difference between the matrix and the stack layer, effectively eliminates the interface stress concentration under the conditions of rapid cooling and heating, and makes the stack product maintain structural integrity in thermal shock cycles.

[0116] 4、The present application forms a microcrystalline phase with matched refractive index while inhibiting grain boundary pores through the synergistic effect of rare earth stabilizers and nano zinc oxide, breaks through the bottleneck of mutual restriction between light transmittance and mechanical strength in traditional transparent ceramics, and meets the high-standard application requirements of optical functional ceramics. DETAILED DESCRIPTION

[0117] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0118] Embodiments 1-3: Ceramic stack regulator and preparation method

[0119] The mass percentages of the components in the following embodiments are calculated based on the total mass of the finally obtained solid dry powder regulator. The balance not listed is mainly the solvent (such as deionized water, ethanol) and other auxiliaries added in the preparation process, which have been removed in subsequent steps such as spray drying. Embodiment 1:

[0120] Ceramic stack regulator composition (mass percentage):

[0121] Zirconium silicate modified with zinc oxide matrix: 20.0%;

[0122] Among them, zirconium silicate accounts for 80.0% of the mass of the matrix, and zinc oxide accounts for 20.0%;

[0123] Nano-composite reinforcing agent: 10.0%;

[0124] Among them, nano TiO2 accounts for 68.0% of the mass of the reinforcing agent, and nano Al2O3 accounts for 32.0%; the molar ratio is 2.5:1;

[0125] Gradient melting regulator: 35.8%;

[0126] Among them, spodumene accounts for 57.8% of the mass of the regulator, quartz accounts for 41.1%, and zinc borate accounts for 1.1%;

[0127] Light transmission optimization agent: 13.0%;

[0128] In the formula, the potassium feldspar accounts for 49.6% of the mass of the optimizing agent, the sodium feldspar accounts for 49.6%, and the calcium phosphate accounts for 0.8%;

[0129] The rare earth stabilizer is 4.0%;

[0130] In the formula, Y2O3 accounts for 80.0% of the mass of the stabilizer, and ZnO accounts for 20.0%;

[0131] The preparation steps are as follows:

[0132] 1. Pretreatment:

[0133] The spodumene and quartz are crushed to D90=50μm, mixed in a mass ratio of 1.41:1, and 1.1% of the total amount of zinc borate is added and dry mixed for 30 minutes.

[0134] 2. Activation of the nano-composite reinforcing agent:

[0135] The nano TiO2 / Al2O3 (molar ratio 2.5:1) is soaked in a 5.0vol% nitric acid solution for 2 hours, ultrasonically treated (frequency 40kHz, power 200W) for 2 hours, and centrifuged to pH=6.8.

[0136] 3. Wet ball milling:

[0137] Ball milling medium: zirconia beads (0.4mm), ball-to-material ratio 9:1;

[0138] Solvent: deionized water / ethanol=2.5:1 (v / v);

[0139] Speed: 300rpm, time: 6 hours.

[0140] 4. Spray drying:

[0141] Inlet temperature: 180℃, outlet temperature: 85℃, powder moisture content: 1.5%.

[0142] 5. Compound aging:

[0143] After mixing the spray-dried powder, the light-transmitting optimizing agent, and the rare earth stabilizer, seal and age for 24 hours (22℃). Example 2:

[0144] Ceramic stack blending agent composition (mass percentage):

[0145] Zinc oxide modified zirconium silicate matrix: 15.0%;

[0146] In the formula, the zirconium silicate accounts for 80.0% of the mass of the matrix, and the zinc oxide accounts for 20.0%;

[0147] Nano-composite reinforcing agent: 8.0%;

[0148] Wherein, nano-TiO2 accounts for 65.0% of the mass of the reinforcing agent, and nano-Al2O3 accounts for 35.0%; the molar ratio is 2.0:1;

[0149] Gradient melting regulator: 30.5%;

[0150] Wherein, spodumene accounts for 59.7% of the mass of the regulator, quartz accounts for 39.8%, and zinc borate accounts for 0.5%;

[0151] Light transmission optimizer: 10.3%;

[0152] Wherein, potassium feldspar accounts for 49.8% of the mass of the optimizer, sodium feldspar accounts for 49.8%, and calcium phosphate accounts for 0.4%;

[0153] Rare earth stabilizer: 3.0%;

[0154] Wherein, Y2O3 accounts for 80.0% of the mass of the stabilizer, and ZnO accounts for 20.0%;

[0155] The preparation steps are as follows:

[0156] 1. Pretreatment:

[0157] Spodumene and quartz are crushed to D90=50μm, mixed in a mass ratio of 1.5:1, and 0.5% of zinc borate is added to the total amount of the regulator, and dry mixed for 25 minutes.

[0158] 2. Activation of nano-composite reinforcing agent:

[0159] Nano-TiO2 / Al2O3 (molar ratio 2.0:1) is soaked in 5.0vol% nitric acid solution for 2 hours, ultrasonic treatment (frequency 40kHz, power 200W) for 2 hours, and centrifuged to pH=7.0.

[0160] 3. Wet ball milling:

[0161] Ball milling medium: zirconia beads (0.3mm), ball-to-material ratio 8:1;

[0162] Solvent: deionized water / ethanol=2:1 (v / v);

[0163] Speed 280rpm, time 5 hours.

[0164] 4. Spray drying:

[0165] Inlet temperature 175℃, outlet temperature 80℃, moisture content 1.2%.

[0166] 5. Compound aging:

[0167] After mixing the spray-dried powder, light transmission optimizer and rare earth stabilizer, seal and age for 22 hours (temperature 20℃). Example 3:

[0168] Ceramic stack harmonizing agent composition (mass percentage):

[0169] Zirconium silicate modified with zinc oxide matrix: 25.0%;

[0170] Among them, zirconium silicate accounts for 80.0% of the mass of the matrix, and zinc oxide accounts for 20.0%;

[0171] Nano-composite reinforcing agent: 12.0%;

[0172] Among them, nano-TiO2 accounts for 70.0% of the mass of the reinforcing agent, and nano-Al2O3 accounts for 30.0%; the molar ratio is 3.0:1;

[0173] Gradient melting regulator: 41.2%;

[0174] Among them, spodumene accounts for 59.2% of the mass of the regulator, quartz accounts for 39.6%, and zinc borate accounts for 1.2%;

[0175] Light transmission optimization agent: 15.8%;

[0176] Among them, potassium feldspar accounts for 49.6% of the mass of the optimization agent, sodium feldspar accounts for 49.6%, and calcium phosphate accounts for 0.8%;

[0177] Rare earth stabilizer: 5.0%;

[0178] Among them, Y2O3 accounts for 90.0% of the mass of the stabilizer, and ZnO accounts for 10.0%;

[0179] The preparation steps are as follows:

[0180] 1. Pretreatment:

[0181] Spodumene and quartz are crushed to D90=30μm, mixed in a mass ratio of 1.5:1, and 1.2% of zinc borate is added to the total amount of the regulator, and dry mixed for 35 minutes.

[0182] 2. Nano-composite reinforcing agent activation:

[0183] Nano-TiO2 / Al2O3 (molar ratio 3.0:1) is soaked in 5.0vol% nitric acid solution for 2.5 hours, ultrasonic treated (frequency 40kHz, power 200W) for 2 hours, and centrifuged to pH=6.5.

[0184] 3. Wet ball milling:

[0185] Ball milling medium: zirconia beads (0.5mm), ball-to-material ratio 10:1;

[0186] Solvent: deionized water / ethanol 3:1 (v / v);

[0187] Rotation speed 320 rpm, time 7 hours.

[0188] 4. Spray drying:

[0189] Inlet temperature 185°C, outlet temperature 90°C, moisture content 1.8%.

[0190] 5. Re-compounding and aging:

[0191] After mixing the spray-dried powder, light-transmission optimizing agent and rare earth stabilizer, the mixture was sealed and aged for 26 hours (temperature 25°C).

[0192] Examples 4-6: Forming and firing method of ceramic stack sculpture Example 4:

[0193] 1. Addition of blending agent:

[0194] Addition ratio of blending agent: 3.0% (total mass of green body);

[0195] Vacuum pugging parameters: vacuum degree -0.092 MPa, pugging 2 times, moisture content of clay 18.0%.

[0196] 2. Layered forming:

[0197] Thickness of base layer: 2.0 mm (without addition of blending agent);

[0198] Thickness of stack layer: 0.2 mm (mechanically extruded).

[0199] 3. Gradient firing:

[0200] First stage: temperature increased to 600°C at a rate of 20°C / min, and kept for 35 minutes;

[0201] Second stage: temperature increased to 950°C at a rate of 4°C / min, and kept for 70 minutes;

[0202] Third stage: temperature increased to 1280°C at a rate of 2°C / min, and kept for 2.5 hours;

[0203] Cooling control: cooling rate 2°C / min above 800°C, and natural cooling below 800°C. Example 5:

[0204] 1. Addition of blending agent:

[0205] Addition ratio of blending agent: 8.0% (total mass of green body);

[0206] Vacuum pugging parameters: vacuum degree -0.098 MPa, pugging 3 times, moisture content of clay 22.0%.

[0207] 2. Layered forming:

[0208] Matrix base layer thickness: 3.0 mm (without addition of the blending agent);

[0209] Stacked layer thickness: 1.0 mm (hand-carved into shape).

[0210] 3. Gradient firing:

[0211] First stage: temperature increase at 25°C / min to 600°C, holding for 25 minutes;

[0212] Second stage: temperature increase at 6°C / min to 950°C, holding for 50 minutes;

[0213] Third stage: temperature increase at 4°C / min to 1350°C, holding for 1.5 hours;

[0214] Cooling control: temperature decrease rate of 1.5°C / min above 800°C, natural cooling below 800°C. Example 6:

[0215] 1. Blending agent addition:

[0216] Blending agent addition ratio: 5.0% (total mass of the blank);

[0217] Vacuum kneading parameters: vacuum degree -0.095 MPa, kneading 2 times, moisture content of the clay 19.0%.

[0218] 2. Layered molding:

[0219] Matrix base layer thickness: 2.6 mm (without addition of the blending agent);

[0220] Stacked layer thickness: 0.5 mm (mechanically extruded into shape).

[0221] 3. Gradient firing:

[0222] First stage: temperature increase at 22°C / min to 600°C, holding for 30 minutes;

[0223] Second stage: temperature increase at 5°C / min to 950°C, holding for 60 minutes;

[0224] Third stage: temperature increase at 3°C / min to 1300°C, holding for 2 hours;

[0225] Cooling control: temperature decrease rate of 2°C / min above 800°C, natural cooling below 800°C.

[0226] Comparative Examples 1-5:

[0227] Comparative Example 1:

[0228] Compared with Example 1, the difference is that the zirconium silicate is not modified with zinc oxide, and the ordinary zirconium silicate (ZrSiO4) is directly used as the matrix, and no zinc oxide (ZnO) is added, and the rest of the components and the preparation process are the same.

[0229] Comparative Example 2:

[0230] Compared with Example 1, the difference is that the molar ratio of TiO2 to Al2O3 in the nano-composite reinforcing agent is 1.0:1, and the rest of the component proportions and process parameters are the same.

[0231] Comparative Example 3:

[0232] Compared with Example 1, the difference is that no zinc borate (ZnO·B2O3) is added in the gradient melting regulator, only lithium feldspar and quartz (mass ratio 1.35:1) are retained, and the rest of the components and the process are the same.

[0233] Comparative Example 4:

[0234] Compared with Example 1, the difference is that only zinc oxide (ZnO) is used in the rare earth stabilizer, and no yttrium oxide (Y2O3) is added, and the rest of the components and the process are the same.

[0235] Comparative Example 5:

[0236] Compared with Example 1, the difference is that the pickling activation step of the nano-composite reinforcing agent is omitted (not treated with nitric acid solution), and the unactivated nano-TiO2 / Al2O3 is directly used, and the rest of the process parameters are the same.

[0237] Test Examples 1-5:

[0238] Test Example 1:

[0239] Purpose: To verify the effect of zinc oxide modified zirconium silicate matrix on improving high temperature bonding performance and thermal shock stability.

[0240] The experimental steps are as follows:

[0241] 1. Sample preparation

[0242] Example 1 group: prepare the adjusting agent according to Example 1, use the firing method of Example 5 (adjusting agent addition amount 8.0%, final firing temperature 1350℃), and prepare a stack sample with a size of 50×10×5mm (3.0mm in the bottom layer, 1.0mm in the stack layer).

[0243] Comparative Example 1 group: prepare the adjusting agent according to Comparative Example 1 (unmodified zirconium silicate matrix), and the rest of the parameters are consistent with Example 1 group.

[0244] Prepare 6 parallel samples for each group.

[0245] 2. High temperature flexural strength test

[0246] Equipment: High temperature three-point bending tester (Model HT-1000Z, maximum temperature 1500℃);

[0247] Conditions: Heat the sample to 1300℃ and keep for 30 minutes, test the flexural strength at a loading rate of 1.0 mm / min;

[0248] Record: Take the average value and standard deviation of 6 samples.

[0249] 3. Thermal shock stability test

[0250] Equipment: High temperature furnace (1300℃) and cold water tank (25℃);

[0251] Steps:

[0252] (1) Heat the sample to 1350℃ and keep for 10 minutes;

[0253] (2) Quickly immerse in 25℃ water for rapid cooling, repeat 3 cycles;

[0254] (3) Observe the number of surface cracks (unit area: cm 2 ).

[0255] The experimental results are shown in Table 1:

[0256] Table 1 High temperature flexural strength and thermal shock stability test data

[0257]

[0258] From the data analysis in Table 1, we can get:

[0259] The high temperature bonding performance of zinc oxide modified zirconium silicate matrix is improved due to the formation of ZnO-ZrSiO4 composite phase in the high temperature solid phase reaction of ZnO and zirconium silicate. The composite phase strengthens the grain boundary bonding force through ion substitution of Zn 2+ and zirconium silicate lattice at high temperature of 1250-1350℃, and the generated trace amount of low melting point glass phase fills the pores, thereby significantly improving the high temperature flexural strength of the matrix. The experimental data show that the flexural strength of the modified matrix at 1300℃ reaches 135.5MPa, which is about 49.2% higher than that of the unmodified matrix, verifying the key role of the composite phase structure in thermal stability.

[0260] The improvement of thermal shock stability is due to the gradient matching of the thermal expansion coefficient of the matrix and the stack layer after modification of zinc oxide. The introduction of ZnO adjusts the thermal expansion coefficient of zirconium silicate, making the difference between the thermal expansion of the nano-enhancing agent and the rare earth stabilizer in the stack layer reduce to 0.3×10 -6below 1000℃. This gradient matching effectively relieves the interface stress concentration during the quenching process. The experimental results show that the modified matrix only has 0.7 cracks per cm2 after three thermal shock cycles, while the crack density of the traditional matrix is as high as 6.8 cracks per cm2 due to the thermal expansion mismatch. 2 2 .

[0261] Through the synergistic effect of zinc oxide modification and gradient melting regulator, this technology solves the interface peeling and thermal shock failure problems of traditional zircon silicate matrix in high temperature stack applications. The high temperature stability of the complex phase structure and the stress buffering effect of the glass phase work together to make the stack product still maintain structural integrity and functionality under complex thermal cycling conditions, providing a reliable material basis for high-precision ceramic stack process.

[0262] Test Example 2:

[0263] Objective: To verify the effect of the molar ratio of nano-TiO2 / Al2O3 composite reinforcing agent on the room temperature mechanical properties and forming stability of the stack layer.

[0264] The experimental steps are as follows:

[0265] 1. Sample preparation

[0266] Example 1 group: Prepare the blending agent (TiO2 / Al2O3 molar ratio 2.5:1) according to Example 1, use the firing method of Example 4 (blending agent addition amount 3.0%, final firing temperature 1280℃), prepare stack samples with size of 80×20×5mm (bottom layer 2.0mm, stack layer 0.2mm).

[0267] Comparative Example 2 group: Prepare the blending agent according to Comparative Example 2 (TiO2 / Al2O3 molar ratio 1.0:1), and the rest of the parameters are consistent with Example 1 group.

[0268] Prepare 6 parallel samples for each group.

[0269] 2. Room temperature flexural strength test

[0270] Equipment: Universal material testing machine (model UTM-500, range 500kN);

[0271] Conditions: Three-point bending method, span 60mm, loading rate 0.5mm / min;

[0272] Record: Record the maximum load at the time of sample fracture, and calculate the flexural strength.

[0273] 3. Dry shrinkage test

[0274] Equipment: Precision digital caliper (accuracy ±0.01mm);

[0275] Steps:​

[0276] (1) Measure the length of the green body after the stack is formed (L0);

[0277] (2) Measure the length of the dry body after drying to a moisture content of ≤1.0% (L1);

[0278] (3) Calculate the shrinkage: [(L0-L1) / L0] x 100%.

[0279] The experimental results are shown in Table 2:

[0280] Table 2 Effect of nano-enhancer ratio on flexural strength and shrinkage

[0281]

[0282] From the data analysis in Table 2, we can obtain:

[0283] When the molar ratio of nano-TiO2 to Al2O3 is optimized to 2.5:1, a continuous three-dimensional network skeleton structure is formed through the directional bonding of surface hydroxyl groups. The synergistic effect of the high activity (001 crystal plane) of TiO2 and the bridging oxygen sites of Al2O3 builds a penetrating nano-enhanced path in the stack layer, significantly improving the flexural strength. The experimental data show that the flexural strength under the optimized ratio reaches 120.0 MPa, which is 42.2% higher than that under the non-equilibrium ratio (1.0:1), verifying the key contribution of nanoparticle synergistic dispersion to mechanical properties.

[0284] The difference in drying shrinkage is due to the influence of nanoparticle dispersion state on the densification of the green body. When the molar ratio of TiO2 / Al2O3 is imbalanced, the excess of Al2O3 leads to local agglomeration of nanoparticles due to electrostatic repulsion, hindering the uniform filling of the slurry in the pores. This makes the drying shrinkage of Comparative Example 2 (1.61%) nearly double that of Example 1 (0.81%), indicating that the optimized ratio can effectively inhibit the structural defects caused by uneven dispersion.

[0285] The formation of the three-dimensional network skeleton further reduces the influence of plastic deformation on the precision of the stack. Nano-TiO2 locks the displacement of Al2O3 through chemical bonding, allowing the stack layer to maintain dimensional stability during drying and firing. This mechanism works synergistically with the gradient firing system to achieve high-precision forming of complex relief patterns, solving the pattern distortion problem caused by uneven shrinkage in traditional processes.

[0286] Test Example 3:

[0287] Objective: To verify the regulating effect of zinc borate (ZnO·B2O3) in the gradient melting regulator on the thermal expansion matching of the stack layer and the substrate interface.

[0288] Experimental steps

[0289] The sample preparation is as follows:

[0290] Example 1 group: prepare the blend (gradient melting modifier containing zinc borate) according to Example 1, use the firing method of Example 5 (final firing temperature 1350°C), prepare the double-layer structure sample (3.0mm for the bottom layer, 1.0mm for the stack layer).

[0291] Comparative Example 3 group: prepare the blend according to Comparative Example 3 (without zinc borate), the rest of the parameters are consistent with Example 1 group.

[0292] Prepare 6 parallel samples for each group.

[0293] 2. Thermal expansion coefficient difference (ΔCTE) test

[0294] Equipment: thermal dilatometer (model DIL-402C, temperature range RT~1400°C);

[0295] Conditions:

[0296] (1) Test the thermal expansion coefficients (25~800°C) of the bottom layer and the stack layer respectively;

[0297] (2) Calculate the difference ΔCTE (unit: 10 -6 / ℃) between the two.

[0298] 3. Interface cracking rate observation

[0299] Equipment: optical microscope (magnification 50x);

[0300] Steps:

[0301] (1) Cut and polish the fired sample along the interface direction;

[0302] (2) Count the number of cracks per unit area (mm 2 );

[0303] (3) Exclude edge effects (only observe the central area of 10x10mm).

[0304] The experimental results are shown in Table 3:

[0305] Table 3 Thermal expansion coefficient difference and interface crack density test results

[0306]

[0307] From the data analysis in Table 3, we can get:

[0308] The introduction of zinc borate forms a continuous transition intermediate layer during high-temperature firing by adjusting the viscosity gradient of the molten glass phase. This intermediate layer is produced by the staged melting of zinc borate, lithium feldspar, and quartz, and its viscosity increases from 10 3Pa s (600°C) gradually decreased to 10 Pa s (950°C), effectively filling the micro-pores between the matrix and the stack layer. Experimental data showed that the difference in the coefficient of thermal expansion of the sample containing zinc borate decreased to 0.31 x 10 -6 / ℃, which was 74.6% lower than that of the sample without the addition of zinc borate, confirming the buffering effect of the transition layer on the thermal expansion mismatch.

[0309] The inhibition of interface cracks is due to the dispersion mechanism of the glass phase generated by zinc borate to the residual stress. During the cooling process, the low viscosity glass phase preferentially fills the grain boundary defects and absorbs thermal stress through plastic deformation, avoiding crack initiation caused by stress concentration. In Comparative Example 3, due to the lack of zinc borate, a rigid contact is formed at the interface, and the thermal expansion difference is directly converted into tensile stress, resulting in a crack density of 2.5 cracks / mm 2 , while the crack density of Example 1 was only 0.10 cracks / mm 2 .

[0310] The synergistic melting behavior of zinc borate with spodumene and quartz further optimizes the chemical stability of the glass phase. The B2O3 in zinc borate forms a [BO3] + -Li - complex structure with Li + in spodumene, enhancing the anti-crystallization ability of the glass phase at high temperatures. This structure remains stable during multiple thermal cycles, allowing the stack product to maintain interface integrity in a severe temperature change environment, solving the durability problem caused by the brittleness of the glass phase in traditional processes.

[0311] Test Example 4:

[0312] Objective: To verify the improvement effect of the synergistic effect of rare earth yttrium oxide (Y2O3) and zinc oxide (ZnO) on the light transmittance and light scattering loss of the ceramic stack layer.

[0313] The experimental steps are as follows:

[0314] 1. Sample preparation

[0315] Example 1 group: Prepare the tempering agent (containing Y2O3 / ZnO stabilizer) according to Example 1, use the firing method of Example 5 (final firing temperature 1350°C), and prepare transparent stack slices (diameter 30mm) with a thickness of 1.0mm.

[0316] Comparative Example 4 group: Prepare the tempering agent according to Comparative Example 4 (containing only ZnO stabilizer), and the rest of the parameters are consistent with Example 1 group.

[0317] Prepare 6 parallel samples for each group.

[0318] 2. Light transmittance test

[0319] Equipment: UV-Vis spectrophotometer (model UV-3600, wavelength range 200-800 nm);

[0320] Conditions:

[0321] (1) Test the light transmittance at 550 nm wavelength with air as the reference;

[0322] (2) Measure each sample 3 times and take the average.

[0323] 3. Light scattering loss test

[0324] Equipment: Integrating sphere (diameter 150 mm) with spectrometer (Ocean Optics USB4000);

[0325] Steps:

[0326] (1) Laser light source (wavelength 550 nm) vertically incident on the sample surface;

[0327] (2) Measure the total transmitted light intensity (I t ) and scattered light intensity (I s );

[0328] (3) Calculate the scattering rate: I s / I t x 100%.

[0329] The experimental results are shown in Table 4:

[0330] Table 4 Test results of light transmittance and light scattering loss

[0331]

[0332] From the data analysis in Table 4, we can get:

[0333] The introduction of rare earth yttrium oxide forms Y2ZnO4 spinel structure through solid phase reaction with zinc oxide, which inhibits the formation of pores at the grain boundaries at high temperature. The high field strength characteristics of Y 3+ make it preferentially occupy the grain boundary defect sites, and cooperatively fill the micro-pores of zirconium silicate matrix with ZnO, reducing the light scattering source. Experimental data show that the light transmittance of Example 1 containing Y2O3 is 81.5%, which is 23.3% higher than that of Comparative Example 4 containing only ZnO, verifying the key role of rare earth stabilizer in grain boundary densification.

[0334] The reduction of light scattering loss is attributed to the homogeneous dispersion of YPO4 crystalline phase induced by Y2O3. The refractive index of YPO4 (1.95) is close to that of zircon (1.92), which effectively reduces the interface reflection loss. The comparative example 4 containing ZnO only does not form such crystalline phase, and the pores left at the grain boundary result in a scattering rate as high as 23.1%. The significant difference between the light transmittance and the scattering rate proves the regulation mechanism of Y2O3 on optical homogeneity.

[0335] The synergistic effect of Y2O3 and ZnO further optimizes the crystallization behavior of the glass phase. Y 3+ By inhibiting the excessive volatilization of ZnO, the high-temperature stability of the glass phase is maintained, and the fogging phenomenon caused by secondary crystallization during the cooling process is avoided. This double regulation enables the stack layer to maintain high light transmittance while having mechanical strength, solving the technical contradiction between light transmittance and strength in traditional transparent ceramics.

[0336] Test example 5:

[0337] Objective: To verify the improvement of nitric acid pickling activation treatment on the dispersion of nanoparticles and the mechanical properties of the stack layer.

[0338] The experimental steps are as follows:

[0339] 1. Sample preparation

[0340] Example 1 group: Prepare the blending agent according to example 1 (nanoparticles are activated by nitric acid pickling), use the sintering method of example 4 (final sintering temperature is 1280℃), and prepare the stack sample with a size of 50x10x5mm.

[0341] Comparative example 5 group: Prepare the blending agent according to comparative example 5 (without acid pickling activation), and the other parameters are consistent with example 1 group.

[0342] Prepare 6 parallel samples for each group.

[0343] 2. Flexural strength test

[0344] Equipment: Universal material testing machine (model UTM-200, range 200kN);

[0345] Conditions: Three-point bending method, span 40mm, loading rate 0.2mm / min;

[0346] Record: Test the maximum load when the sample breaks, and calculate the flexural strength.

[0347] 3. Slurry dispersion test

[0348] Equipment: Laser particle size analyzer (model LS-230, measurement range 0.02-2000μm);

[0349] Steps:

[0350] (1) Take the slurry of the blending agent before firing, dilute to 5% solid content;

[0351] (2) Test the particle size distribution immediately after ultrasonic dispersion for 5 minutes;

[0352] (3) Record the D90 value (the particle size corresponding to the cumulative distribution of 90%).

[0353] The experimental results are shown in Table 5:

[0354] Table 5 Influence of pickling activation on flexural strength and slurry dispersibility

[0355]

[0356] From the data analysis in Table 5, it can be concluded that:

[0357] The nitric acid pickling activation treatment exposes the high-activity (001) crystal surface and surface hydroxyl groups by selectively etching the amorphous oxide layer on the surface of the nanoparticles. This treatment significantly reduces the absolute value of the Zeta potential of the nanoparticles (from -35 mV to -22 mV), weakens the electrostatic repulsion, and promotes the uniform dispersion of the particles in the slurry. The experimental data show that the D90 value of the slurry after pickling decreases to 1.56 μm, which is 69.3% lower than that of the untreated group, and the flexural strength simultaneously increases to 119.0 MPa, verifying the key role of surface activation in the synergistic optimization of dispersibility and strength.

[0358] The improvement in dispersibility directly affects the sintering densification process. The activated nanoparticles form a Si-O-Zr covalent bond network with the zirconium silicate matrix through the surface hydroxyl groups, preferentially diffuse along the grain boundaries during the firing process, fill the pores, and inhibit abnormal grain growth. The comparative example 5, due to the absence of pickling, leads to nanoparticle agglomeration (D90 reaches 5.09 μm), and micron-sized pores are formed at the grain boundaries after firing, resulting in a flexural strength of 72.8 MPa, which is only 61.2% of that of example 1.

[0359] The synergistic effect of pickling activation and gradient firing regime further strengthens the interfacial bonding. The activated nanoparticles form a pre-skeleton through chemical bonding at low temperatures (<800°C), and eliminate residual pores through liquid phase sintering at high temperatures (>1100°C). This staged densification mechanism solves the contradiction between dispersibility and sintering activity in traditional processes, and provides a reliable path for the industrial production of high-precision nanocomposite ceramics.

[0360] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A ceramic sculpturing paste characterized by, comprises the following components by mass percentage: zirconium silicate matrix modified by zinc oxide 15% to 25%, nano-composite reinforcing agent 8% to 12%, gradient melting regulator 30.5% to 41.2%, light transmission optimization agent 10.3% to 15.8%, and rare earth stabilizer 3% to 5%; the gradient melting regulator comprises spodumene, quartz, and 0.5% to 1.2% zinc borate, and the mass ratio of the spodumene to the quartz is (1.41:1) to (1.5:1); the nano-composite reinforcing agent is a composite powder of nano-TiO2 and Al2O3, and the molar ratio of the nano-TiO2 to the Al2O3 is (2:1) to (3:1); the rare earth stabilizer comprises yttrium oxide and zinc oxide, and the yttrium oxide accounts for 80% to 90% of the total mass of the rare earth stabilizer; the light transmission optimization agent is compounded by potassium feldspar and sodium feldspar at a mass ratio of 1:1, and contains 0.4% to 0.8% calcium phosphate; the zirconium silicate matrix modified by zinc oxide is a composite phase formed by high-temperature solid-phase reaction of zirconium silicate and zinc oxide, and the zinc oxide accounts for 20% of the mass of the matrix.

2. A method of preparing the ceramic stack sculpturing paste as claimed in claim 1, wherein, comprises the following steps: (1) pretreatment and activation: spodumene and quartz are crushed to D90≤50μm, mixed at a mass ratio, 0.5% to 1.2% zinc borate is added to the total amount of the regulator, the nano-composite reinforcing agent is soaked in 5.0vol% nitric acid solution for 2 to 2.5 hours, ultrasonic treated for 2 hours, and centrifuged and washed until pH=6.5 to 7.0; (2) wet ball milling: the zirconium silicate matrix modified by zinc oxide, the nano-composite reinforcing agent, the gradient melting regulator, and the solvent are mixed and ball milled, the ball milling medium is zirconia beads with a particle size of 0.3 to 0.5mm, the ball-to-material ratio is (8:1) to (10:1), the ball milling speed is 280 to 320rpm, and the time is 5 to 7 hours; (3) spray drying: the ball milled slurry is spray dried to form submicron powder, the spray drying inlet temperature is 175 to 185℃, the outlet temperature is 80 to 90℃, and the water content of the powder is 1.2% to 1.8%; (4) compounding and aging: the light transmission optimization agent and the rare earth stabilizer are mixed with the spray dried powder, and after mixing, the mixture is sealed and aged for 22 to 26 hours at a temperature of 20 to 25℃.

3. A forming and firing method of a ceramic relief product, characterized by, comprises the following steps: (1) clay blending: the ceramic sculpture building regulator of claim 1 is added at 3.0% to 8.0% of the total mass of the green body, and after vacuum kneading, plastic clay is obtained; (2) layered sculpture forming: the green body with the same source as step (1) is taken, and without adding the blending agent, it is pressed into a bottom layer with a thickness of 2.0 to 3.0mm; the clay containing the blending agent prepared in step (1) is stacked on the surface of the bottom layer, and a sculpture layer with a thickness of 0.2 to 1.0mm is formed by carving or mechanical extrusion; (3) gradient sintering: the temperature is raised to 600℃ at a rate of 20 to 25℃ / min and held for 25 to 35 minutes; the temperature is raised to 950℃ at a rate of 4 to 6℃ / min and held for 50 to 70 minutes; the temperature is raised to 1280 to 1350℃ at a rate of 2 to 4℃ / min and held for 1.5 to 2.5 hours; Control the cooling rate to be less than or equal to 2℃ / min above 800℃, and naturally cool below 800℃.

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