阅读说明：本技术 一种铌酸钾钠基无铅压电陶瓷粉末与浆料及其制备工艺 (Potassium-sodium niobate-based leadless piezoelectric ceramic powder and slurry and preparation process thereof ) 是由 龚文 徐高翅 吴超峰 于 2020-06-12 设计创作，主要内容包括：本发明提出一种用于光固化3D打印的一种铌酸钾钠基无铅压电陶瓷粉末与浆料及其制备工艺,采用锂、钡、钙、钛和钴元素进行掺杂,获得改性的铌酸钾钠基压电陶瓷粉末；采用光引发剂、光敏树脂、分散剂、消泡剂在搅拌机预混合获得各组分均匀的树脂混合液；获得的改性铌酸钾钠基压电陶瓷粉末和树脂混合液搅拌机预混合,然后在球磨机充分混合,最后在真空脱泡机抽真空脱泡,从而得到成分均匀的、粘度适中的、光固化活性高的无铅压电陶瓷浆料。该浆料适用于光固化陶瓷3D打印机,可成型的各种复杂形状的,优异的压电性能和高致密度的无铅压电陶瓷元器件。(The invention provides potassium-sodium niobate-based leadless piezoelectric ceramic powder and slurry for photocuring 3D printing and a preparation process thereof, wherein lithium, barium, calcium, titanium and cobalt elements are adopted for doping to obtain modified potassium-sodium niobate-based piezoelectric ceramic powder; pre-mixing a photoinitiator, photosensitive resin, a dispersant and a defoaming agent in a stirrer to obtain a resin mixed solution with uniform components; the obtained modified potassium sodium niobate-based piezoelectric ceramic powder is premixed with a resin mixed solution stirrer, then fully mixed in a ball mill, and finally vacuumized and defoamed in a vacuum defoaming machine, so that the lead-free piezoelectric ceramic slurry with uniform components, moderate viscosity and high photocuring activity is obtained. The slurry is suitable for photocuring ceramic 3D printers, and can be used for forming lead-free piezoelectric ceramic components with various complex shapes, excellent piezoelectric performance and high density.)

1. A potassium-sodium niobate based leadless piezoelectric ceramic powder is characterized in that: the chemical composition is as follows: (1-x) (K)_{1-a- b}Na_bLi_a)NbO₃+x(Ba_0.6Ca_0.4)TiO₃+yCo₂O₃(ii) a The a, b, x and y are mole percent and 0<a≤0.1，0.3≤b≤0.5，0.1≤x≤0.2，0<y≤1%。

2. The potassium sodium niobate-based lead-free piezoelectric ceramic slurry prepared from the potassium sodium niobate-based lead-free piezoelectric ceramic powder according to claim 1, characterized in that: the components are as follows: comprises the potassium sodium niobate-based lead-free piezoelectric ceramic powder and photosensitive resin mixed solution; the weight of the potassium sodium niobate based leadless piezoelectric ceramic powder accounts for 70-85% of the total weight of the slurry, and the weight of the photosensitive resin mixed solution accounts for 15-30% of the total weight of the slurry.

3. The potassium sodium niobate-based lead-free piezoelectric ceramic slurry as set forth in claim 2, wherein: the photosensitive resin mixed solution comprises the following components: photoinitiator, dispersant, defoaming agent and photosensitive resin.

4. The potassium sodium niobate-based lead-free piezoelectric ceramic slurry as set forth in claim 3, wherein: the photosensitive resin mixed solution comprises the following components in percentage by weight: 1-3% of photoinitiator, 4-8% of dispersant, 2-4% of defoaming agent and 85-93% of photosensitive resin.

5. The potassium sodium niobate-based lead-free piezoelectric ceramic slurry as set forth in claim 3, wherein: the photoinitiator is bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide.

6. The potassium sodium niobate-based lead-free piezoelectric ceramic slurry as set forth in claim 3, wherein: the photosensitive resin is one or more of mixed liquid of polyvinyl chloride (methyl) acrylate and polyester (methyl) acrylate.

7. The potassium sodium niobate-based lead-free piezoelectric ceramic slurry as set forth in claim 3, wherein: the dispersant is triammonium citrate (TAC).

8. The potassium sodium niobate-based lead-free piezoelectric ceramic slurry as set forth in claim 3, wherein: the defoaming agent is ethylene glycol.

9. The process for preparing a potassium sodium niobate-based lead-free piezoelectric ceramic powder according to claim 1, comprising the steps of:

(1) raw material powder pretreatment: putting potassium carbonate, sodium carbonate, niobium pentoxide, barium carbonate, calcium carbonate, titanium dioxide and cobalt trioxide powder into a culture dish, putting the culture dish into a drying box, and preserving heat for 2-4h at the temperature of 100-;

(2) mixing raw material powder: weighing the pretreated raw materials according to the chemical composition ratio of claim 1, dispersing in pure water, mixing uniformly in a ball mill, and drying to obtain premixed powder;

(3) pre-sintering mixed powder: placing the premixed powder in a box-type furnace, continuously heating to 800-1200 ℃, preserving heat for 4-8h, cooling to room temperature, grinding the marble in a mortar, and further sieving to obtain modified potassium sodium niobate-based lead-free piezoelectric ceramic powder;

(4) pre-sintering powder ball milling: and dispersing the pre-sintered modified potassium sodium niobate-based lead-free piezoelectric ceramic powder into pure water, uniformly mixing in a ball mill, and drying to obtain the modified potassium sodium niobate-based lead-free piezoelectric ceramic powder with uniform size.

10. The process for preparing potassium-sodium niobate-based lead-free piezoelectric ceramic slurry according to any one of claims 2 to 8, wherein the potassium-sodium niobate-based lead-free piezoelectric ceramic powder and the photosensitive resin mixed solution are mixed in proportion, stirred in a mechanical stirrer, further fully mixed in a ball mill, further vacuum defoamed in a vacuum defoaming machine, and finally the potassium-sodium niobate-based lead-free piezoelectric ceramic slurry is obtained.

Technical Field

The invention relates to the field of 3D printing of photocuring ceramics, in particular to potassium-sodium niobate-based lead-free piezoelectric ceramic powder and slurry and a preparation process thereof.

Background

The photocuring ceramic 3D printing technology is mature day by day in recent years, and the 3D printing has the advantages of simple operation, high processing speed, high forming precision and the like, and can form ceramic products with complex structures on the premise of not needing a mould. The 3D printing technology of photo-cured ceramics is being widely applied to the preparation of ceramic products.

The piezoelectric material is widely applied to the fields of intelligent electronic products, unmanned planes, robots, unmanned planes and the like at present, and has a huge market prospect. However, lead zirconate titanate (PZT) -based piezoelectric materials, which are piezoelectric materials used in various industries at present, occupy most of the share, and lead (Pb) is harmful to human bodies and the environment, so that the development of new lead-free piezoelectric materials is an indispensable trend. The potassium-sodium niobate based lead-free piezoelectric ceramic is obtained by doping other elements, the piezoelectric performance of the modified potassium-sodium niobate based lead-free piezoelectric ceramic is excellent, and meanwhile, the doped elements can obtain a high-density piezoelectric material. The potassium sodium niobate based lead-free piezoelectric ceramic material which is environment-friendly is expected to gradually replace lead zirconate titanate (PZT) based piezoelectric materials and become a main piezoelectric material.

Disclosure of Invention

The invention aims to provide potassium-sodium niobate-based lead-free piezoelectric ceramic slurry and powder and a preparation process thereof, so as to solve the problems in the background art.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a potassium-sodium niobate based leadless piezoelectric ceramic powder comprises the following chemical components:

(1-x)(K_1-a-bNa_bLi_a)NbO₃+x(Ba_0.6Ca_0.4)TiO₃+yCo₂O₃(ii) a The a, b, x and y are mole percent and 0<a≤0.1，0.3≤b≤0.5，0.1≤x≤0.2，0<y≤1%。

A potassium-sodium niobate-based leadless piezoelectric ceramic slurry comprises the following components: comprises the potassium sodium niobate-based lead-free piezoelectric ceramic powder and photosensitive resin mixed solution; the weight of the potassium sodium niobate based leadless piezoelectric ceramic powder accounts for 70-85% of the total weight of the slurry, and the weight of the photosensitive resin mixed solution accounts for 15-30% of the total weight of the slurry.

Further, the composition of the photosensitive resin mixed solution includes: photoinitiator, dispersant, defoaming agent and photosensitive resin.

Further, the photosensitive resin mixed solution comprises the following components in percentage by weight: 1-3% of photoinitiator, 4-8% of dispersant, 2-4% of defoaming agent and 85-93% of photosensitive resin.

Further, the photoinitiator is bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide.

Further, the photosensitive resin is a mixed liquid of one or more of a polyvinyl chloride (meth) acrylate and a polyester (meth) acrylate.

Further, the dispersant is triammonium citrate (TAC).

Further, the defoaming agent is ethylene glycol.

The invention also comprises a preparation process of the potassium-sodium niobate based leadless piezoelectric ceramic powder, which comprises the following steps:

(1) raw material powder pretreatment: putting potassium carbonate, sodium carbonate, niobium pentoxide, barium carbonate, calcium carbonate, titanium dioxide and cobalt trioxide powder into a culture dish, putting the culture dish into a drying box, and preserving heat for 2-4h at the temperature of 100-;

(2) mixing raw material powder: weighing the pretreated raw materials according to the chemical composition ratio of claim 1, dispersing in pure water, mixing uniformly in a ball mill, and drying to obtain premixed powder;

(3) pre-sintering mixed powder: placing the premixed powder in a box-type furnace, continuously heating to 800-1200 ℃, preserving heat for 4-8h, cooling to room temperature, grinding the marble in a mortar, and further sieving to obtain modified potassium sodium niobate-based lead-free piezoelectric ceramic powder;

(4) pre-sintering powder ball milling: and dispersing the pre-sintered modified potassium sodium niobate-based lead-free piezoelectric ceramic powder into pure water, uniformly mixing in a ball mill, and drying to obtain the modified potassium sodium niobate-based lead-free piezoelectric ceramic powder with uniform size.

The invention also comprises a preparation process of the potassium-sodium niobate-based lead-free piezoelectric ceramic slurry, wherein the potassium-sodium niobate-based lead-free piezoelectric ceramic powder and the photosensitive resin mixed solution are mixed in proportion, stirred on a mechanical stirrer, further fully mixed in a ball mill, and further vacuumized and defoamed in a vacuum defoaming machine to finally obtain the potassium-sodium niobate-based lead-free piezoelectric ceramic slurry.

The invention has the beneficial effects that: the invention provides a potassium-sodium niobate-based leadless piezoelectric ceramic slurry and a preparation process thereof, which adopts elements of lithium, barium, calcium, titanium and cobalt for doping to obtain modified potassium-sodium niobate-based piezoelectric ceramic powder; pre-mixing a photoinitiator, photosensitive resin, a dispersant and a defoaming agent in a stirrer to obtain a resin mixed solution with uniform components; the obtained modified potassium sodium niobate-based piezoelectric ceramic powder is fully mixed with the resin mixed solution, and finally, the mixture is vacuumized and defoamed, so that the lead-free piezoelectric ceramic slurry with uniform components, moderate viscosity and high photocuring activity is obtained. The slurry is suitable for photocuring ceramic 3D printers, and can be used for forming lead-free piezoelectric ceramic components with various complex shapes, excellent piezoelectric performance and high density.

Drawings

FIG. 1 is a flow chart of the preparation process of the present invention.

Detailed Description

The specific examples are only for further illustration of the present invention and do not limit the scope of the present invention. Any examples made by a person skilled in the art that are within the scope of the claims are to be included within the scope of protection of this patent.

Example one

Putting raw material powders of potassium carbonate, sodium carbonate, niobium pentoxide, barium carbonate, calcium carbonate, titanium dioxide and cobalt trioxide into a culture dish, putting the culture dish into a drying oven, and preserving heat for 2 hours at 120 ℃.

According to chemical composition

0.9(K_0.4Na_0.5Li_0.1)NbO₃+0.1(Ba_0.6Ca_0.4)TiO₃+1%Co₂O₃Weighing the pretreated raw materials in proportion, dispersing the raw materials in pure water, wherein the volume ratio of the raw material powder to the pure water is 1: 1.2; speed on planetary ball mill500rpm, milling time 5 hours; further placing in a drying oven, and keeping the temperature at 130 deg.C for 4h to obtain the dried premixed powder with uniform components.

Placing the premixed powder in a box furnace, continuously heating to 1050 ℃, preserving heat for 8 hours, and cooling to room temperature; further, the pre-fired powder was ground using a marble mortar and sieved through a 100-mesh sieve to obtain a modified potassium sodium niobate-based lead-free piezoelectric ceramic powder.

Dispersing the pre-sintered modified potassium sodium niobate-based lead-free piezoelectric ceramic powder in pure water, wherein the volume ratio of the pre-sintered powder to the pure water is 1: 1.2; the rotating speed on a planet ball mill is 500rpm, and the grinding time is 6 hours; further placing the mixture in a drying oven, and preserving heat for 4 hours at 130 ℃ to obtain the dried modified potassium-sodium niobate-based lead-free piezoelectric ceramic powder with uniform components.

The photoinitiator is bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide accounting for 2% of the weight of the photosensitive resin mixed solution, the dispersant is citric Triamine (TAC) accounting for 5% of the weight of the photosensitive resin mixed solution, the defoaming agent is ethylene glycol accounting for 3% of the weight of the photosensitive resin mixed solution, and the rest photosensitive resin is polyvinyl chloride (methyl) acrylate accounting for 90% of the weight of the photosensitive resin mixed solution.

The potassium sodium niobate based leadless piezoelectric ceramic powder and the photosensitive resin mixed solution are mixed according to the proportion of 85: 15, stirring on a mechanical stirrer at the rotating speed of 450rpm for 4 hours; further grinding for 8 hours on a planet ball mill at the rotating speed of 500 rpm; and further vacuumizing and defoaming in a vacuum defoaming machine to finally obtain the potassium-sodium niobate-based leadless piezoelectric ceramic slurry.

The obtained slurry is used for forming lead-free piezoelectric material products with various complex structures by a photocuring 3D printer, the piezoelectric constant D33 of the piezoelectric material reaches 278pC/N, and the compactness reaches 96.2%.

Example two

Putting raw material powders of potassium carbonate, sodium carbonate, niobium pentoxide, barium carbonate, calcium carbonate, titanium dioxide and cobalt trioxide into a culture dish, putting the culture dish into a drying oven, and preserving heat for 1.5h at 130 ℃.

According to chemical composition

0.85(K_0.55Na_0.4Li_0.05)NbO₃+0.15(Ba_0.6Ca_0.4)TiO₃+0.8%Co₂O₃Weighing the pretreated raw materials in proportion, dispersing the raw materials in pure water, wherein the volume ratio of the raw material powder to the pure water is 1: 1; the rotating speed on a planet ball mill is 600rpm, and the grinding time is 3.5 hours; further placing in a drying oven, and keeping the temperature at 140 deg.C for 2.5h to obtain premixed powder containing oven-dried components.

Placing the premixed powder in a box furnace, continuously heating to 1135 ℃, preserving heat for 7 hours, and cooling to room temperature; further, the pre-fired powder was ground using a marble mortar and sieved through a 120-mesh sieve to obtain a modified potassium sodium niobate-based lead-free piezoelectric ceramic powder.

Dispersing the pre-sintered modified potassium sodium niobate-based lead-free piezoelectric ceramic in pure water, wherein the volume ratio of the pre-sintered powder to the pure water is 1: 1; the rotating speed on a planet ball mill is 600rpm, and the grinding time is 4 hours; further placing the mixture in a drying oven, and preserving heat for 3 hours at 140 ℃ to obtain the dried modified potassium-sodium niobate-based lead-free piezoelectric ceramic powder with uniform components.

The photoinitiator is bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide accounting for 2.5% of the weight of the photosensitive resin mixed solution, the dispersant is citric acid Triamine (TAC) accounting for 6% of the weight of the photosensitive resin mixed solution, the defoaming agent is ethylene glycol accounting for 4% of the weight of the photosensitive resin mixed solution, and the rest of the photosensitive resin is polyester (methyl) acrylate accounting for 87.5% of the weight of the photosensitive resin mixed solution.

The ratio of the potassium sodium niobate-based leadless piezoelectric ceramic powder to the photosensitive resin mixed solution is 80: 20, stirring on a mechanical stirrer at the rotating speed of 500rpm for 3.5 hours; further grinding for 10 hours on a planetary ball mill at the rotating speed of 600 rpm; and further vacuumizing and defoaming in a vacuum defoaming machine to finally obtain the potassium-sodium niobate-based leadless piezoelectric ceramic slurry.

The obtained slurry is used for forming lead-free piezoelectric material products with various complex structures by a photocuring 3D printer, the piezoelectric constant D33 of the piezoelectric material is about 285pC/N, and the compactness reaches 95.3%.

EXAMPLE III

A potassium-sodium niobate based leadless piezoelectric ceramic powder comprises the following chemical components: (1-x) (K)_1-a-bNa_bLi_a)NbO₃+x(Ba_0.6Ca_0.4)TiO₃+yCo₂O₃(ii) a The a, b, x and y are mole percent and 0<a≤0.1，0.3≤b≤0.5，0.1≤x≤0.2，0<y≤1%。

A potassium-sodium niobate-based leadless piezoelectric ceramic slurry comprises the following components: potassium sodium niobate based leadless piezoelectric ceramic powder and photosensitive resin mixed solution; the weight of the potassium sodium niobate based leadless piezoelectric ceramic powder accounts for 70-85% of the total weight of the slurry, and the weight of the photosensitive resin mixed solution accounts for 15-30% of the total weight of the slurry.

The photosensitive resin mixed solution comprises the following components: photoinitiator, dispersant, defoamer and photosensitive resin; the photosensitive resin mixed solution comprises the following components in percentage by weight: 1-3% of photoinitiator, 4-8% of dispersant, 2-4% of defoaming agent and 85-93% of photosensitive resin; the photoinitiator is bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide; the photosensitive resin is one or more of mixed liquid of polyvinyl chloride (methyl) acrylate and polyester (methyl) acrylate; the dispersant is triammonium citrate (TAC); the defoaming agent is ethylene glycol.

The preparation process of potassium-sodium niobate based leadless piezoelectric ceramic powder comprises the following steps:

(1) raw material powder pretreatment: putting potassium carbonate, sodium carbonate, niobium pentoxide, barium carbonate, calcium carbonate, titanium dioxide and cobalt trioxide powder into a culture dish, putting the culture dish into a drying box, and preserving heat for 2-4h at the temperature of 100-150 ℃.

(2) Mixing raw material powder: the method of claim 1, wherein the pretreated raw material is weighed according to the chemical composition ratio and dispersed in pure water, and the volume ratio of the raw material powder to the pure water is 1: (0.8-1.5); the rotation speed on a planet ball mill is 300-600rpm, and the grinding time is 4-12 hours; further placing the mixture in a drying box, and preserving heat for 2-4h at the temperature of 100-150 ℃ to obtain the dried uniformly-mixed powder with the components.

(3) Pre-sintering mixed powder: placing the premixed powder in a box-type furnace, continuously heating to 800-1200 ℃, preserving heat for 4-8h, and cooling to room temperature; further, the powder was ground in a marble mortar and sieved (60 mesh to 200 mesh) to obtain a modified potassium sodium niobate-based lead-free piezoelectric ceramic powder.

(4) Pre-sintering powder ball milling: dispersing the pre-sintered modified potassium sodium niobate-based lead-free piezoelectric ceramic in pure water, wherein the volume ratio of the pre-sintered powder to the pure water is 1: (0.8-1.5); the rotation speed on a planet ball mill is 300-600rpm, and the grinding time is 4-12 hours; further placing the mixture in a drying box, and preserving heat for 2-4h at the temperature of 100-150 ℃ to obtain the modified potassium-sodium niobate leadless piezoelectric ceramic powder with the same dried components.

The preparation process of the photosensitive resin mixed solution comprises the following steps: the components of the photosensitive resin mixed solution are mixed according to the proportion, and the mixture is placed in a beaker and mixed on a magnetic stirrer, the rotating speed is 200-450rpm, and the stirring time is 1-4 hours to obtain the uniform photosensitive resin mixed solution.

The preparation process of the potassium-sodium niobate-based leadless piezoelectric ceramic slurry comprises the following steps: the potassium sodium niobate based leadless piezoelectric ceramic powder and the photosensitive resin mixed solution are mixed according to the proportion and stirred on a mechanical stirrer at the rotating speed of 300-600rpm for 1-4 hours; further the rotation speed on the planet ball mill is 300-600rpm, and the grinding time is 4-12 hours; and further vacuumizing and defoaming in a vacuum defoaming machine to finally obtain the potassium-sodium niobate-based leadless piezoelectric ceramic slurry.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.