CN112174652A

CN112174652A - Photocuring silicon dioxide ceramic slurry and preparation method and application thereof

Info

Publication number: CN112174652A
Application number: CN202011055600.XA
Authority: CN
Inventors: 刘耀; 江泽星
Original assignee: Jiangxi Jinshi 3d Intelligent Manufacturing Technology Co ltd
Current assignee: Jiangxi Jinshi 3d Intelligent Manufacturing Technology Co ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2021-01-05

Abstract

The invention provides a photocuring silica ceramic slurry and a preparation method and application thereof, belonging to the field of functional ceramics. The photocuring silica ceramic slurry provided by the invention is prepared from modified silica powder, acrylate, a diluent and a photoinitiator according to the mass ratio of 10-100:1-60:1-6, mixing; the modified silicon dioxide powder is prepared by mixing silicon dioxide powder, a surface modifier and a dispersing agent according to the mass ratio of 10-80:1-10: 1-6. The photocuring silica ceramic slurry was prepared by vacuum stirring. The invention also provides application of the photocuring silica ceramic slurry in preparation of silica ceramic parts. The photocuring silicon dioxide slurry provided by the invention has stable performance and good uniformity and dispersibility. The silicon dioxide ceramic part prepared by the method has stable mechanical property, and the preparation method is simple, short in time consumption and low in cost.

Description

Photocuring silicon dioxide ceramic slurry and preparation method and application thereof

Technical Field

The invention relates to the technical field of functional ceramics, in particular to photocuring silica ceramic slurry and a preparation method and application thereof.

Background

The additive manufacturing technology changes the traditional 'removal' and 'isometric' manufacturing into 'addition' manufacturing, and has the advantages of short development period, no need of a die, low cost and the like. The method is based on a layering-stacking principle, firstly, a three-dimensional model of a part is generated in three-dimensional modeling software, then slicing processing is carried out on the three-dimensional model, information of each layer is input into manufacturing equipment, and finally any complex three-dimensional solid part is obtained through layer-by-layer accumulation of materials.

Currently, ceramic AM technologies can be classified into 4 types according to the form of raw materials: 1) the AM technology based on powder materials mainly comprises three-dimensional printing (3DP) and Selective Laser Sintering (SLS). Yoo et al, combined with 3DP and isostatic pressing techniques, degrease and sinter at high temperature to obtain an alumina ceramic part with a relative density of 99.2%; fielding et al with ZrO₂And SiO₂In order to add the auxiliary agent, the tricalcium phosphate ceramic part with the relative density of 95 percent is successfully prepared. However, the 3DP technique suffers from low surface resolution and poor accuracy (about 0.2mm) of the molded part. Shahzad produced zirconia ceramic parts with a relative density of 86% using the SLS technique. However, SLS molded articles have poor precision and surface roughness, and are not suitable for producing molded articles having fine microscopic holes ((<500 μm); 2) wire-based ceramic AM technology, mainly Fused Deposition Modeling (FDM). Stuecker and the like successfully manufacture porous mullite ceramic biscuit with the aperture size of 100-1000 mu m by taking mullite as a raw material. However, the forming method has low printing precision, and the surface of a printed part is rough and is not suitable for manufacturing large parts; 3) the sheet-based ceramic AM technology is mainly layered solid fabrication (LOM). The method has the defects that the quality of the manufactured part is influenced by the bonding effect between layers, and the problems of layering, pores on an interface, inconsistent mechanical properties in all directions and the like exist frequently.

In addition to the above ceramic AM technology, it is liquid material-based photo-curing molding (SLA) ceramic AM technology that is currently gaining wide attention and developing relatively mature. According to the SLA technology, photosensitive resin is used as a raw material, and an ultraviolet light source scans liquid photosensitive resin according to cross section information of a three-dimensional model to realize single-layer curing. Then, the table is lowered by a height of one layer thickness, and the ceramic part is obtained. Because the SLA technology has the advantages of high manufacturing accuracy (± 0.1mm), good surface quality, and the ability to manufacture fine parts, it has been successfully applied in the fields of medicine and biology (such as tooth and bone restoration), microtechnology (such as sensors, piezoelectric elements, and photonic crystals), and mechanical heat-resistant structures (such as turbine blades).

The photosensitive resin-based pastes used in SLA technology are generally composed of ceramic powder, monomers, photoinitiators and small amounts of diluents. Because the SLA technology adopts the form of slurry to be cured and formed, the relative density of a blank is higher (>55%), and a high degree of densification can be achieved. For example, Griffith et al are each SiO₂As a sintering aid, the alumina ceramic prepared by the SLA technology has a sintering density close to the theoretical density and a higher surface resolution. Soshu et al used SLA technology to produce several porous ceramic parts with porosity greater than 60% and well-distributed pore sizes. The compactness of a sample of an alumina gear prepared by Cappi et al through SLA forming reaches 3.18g/cm³Hardness of 17.0HV and fracture toughness of 4.4 MPa-m^0.5。

In China, the research and active development of the photocuring process of the resin-based ceramic slurry are carried out by the western-land transportation university, the Huazhong science and technology university and the like. For example, Zhou Wei et al found that the viscosity of the ceramic slurry and the thickness of the cured ceramic slurry are important to the molding process of the ceramic body, and the shrinkage of the ceramic body is related to the volume fraction of the ceramic powder. Qin et al found that photosynthesis was inhibited by the addition of oxygen, the solid phase loading was increased from 40% to 44%, and the sample density reached 2.95g/cm³。

However, the research on the aspect of high-precision alumina SLA forming technology is just started at home and abroad at present, but no relevant report is provided for preparing high-precision and high-density special-shaped ceramic parts.

Disclosure of Invention

In view of the above, the present invention provides a photocurable silica ceramic slurry, and a preparation method and an application thereof, and the photocurable silica ceramic slurry provided by the present invention has stable performance, and when photocuring molding is performed, the molding process is stable, and the obtained silica ceramic has stable performance.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a photocuring silica ceramic slurry, which comprises the following components in part by weight: the modified silicon dioxide powder, the acrylate, the diluent and the photoinitiator are mixed according to the mass ratio of 10-100:1-60:1-60:1-6 to prepare the modified silicon dioxide powder;

the modified silicon dioxide powder is prepared by mixing silicon dioxide powder, a surface modifier and a dispersing agent according to the mass ratio of 10-80:1-10: 1-6.

Preferably, the particle size of the silica powder is 100-800 nm.

Preferably, the acrylate comprises Epoxy Acrylate (EA).

Preferably, the diluent is one or a mixture of 1, 6-hexanediol diacrylate (HDDA) and hydroxyethyl acrylate (HEA) in any proportion, wherein the diluent accounts for 0-60 parts.

Preferably, the photoinitiator is one or a mixture of several of phenyl phosphorus dioxide (819) and 1-hydroxycyclohexyl phenyl ketone (184) in any proportion.

In the present invention, the particle size of the silica powder is preferably 100-800nm, more preferably 400-600 nm. The source of the silica powder in the present invention is not particularly limited, and commercially available products known to those skilled in the art may be used.

In the invention, the photoinitiator is excited to generate active reaction sites such as free radicals or cations under the irradiation of ultraviolet light, and the prepolymer and the active diluent are initiated to generate a crosslinking reaction.

The invention also provides a preparation method of the photocuring silica ceramic slurry in the technical scheme, which comprises the following steps:

(1) stirring and ball-milling the acrylate, the diluent and the photoinitiator according to the mass ratio of 10-60:10-60:1-6 to obtain a resin system;

(2) stirring and ball-milling the silicon dioxide ceramic powder, the surface modifier and the dispersant according to the proportion of 10-80:1-10: 1-6; secondly, drying to finally obtain the well dispersed silicon dioxide powder;

(3) mixing the silicon dioxide ceramic powder obtained in the step (2) with the resin system obtained in the step (1) to obtain photocuring silicon dioxide ceramic slurry;

the steps (1) and (2) are not limited in sequence.

According to the invention, silicon dioxide powder and a diluent are sequentially mixed and dried to obtain silicon dioxide ceramic powder. The mixing method is not particularly limited in the present invention, and the mixing method known to those skilled in the art may be adopted, specifically, stirring. The stirring speed is 350-450r/min, the stirring time is preferably 5-20 min, more preferably 8-15 min, and most preferably 10-12 min. In the present invention, the mixing enables the hydroxyapatite ceramic powder and the diluent to be sufficiently mixed.

In the invention, the drying temperature is preferably 30-80 ℃, more preferably 40-70 ℃, and most preferably 50-60 ℃. In the invention, the drying time is preferably 24-48 h, more preferably 30-40 h, and most preferably 34-36 h.

The invention mixes the active thinner and the photoinitiator to obtain the resin system. The mixing method is not particularly limited in the present invention, and the mixing method known to those skilled in the art may be adopted, specifically, stirring. In the invention, the stirring speed is preferably 350-450r/min, more preferably 375-425 r/min, and most preferably 400 r/min. In the invention, the stirring time is preferably 15-60 min, more preferably 20-50 min, and most preferably 30-40 min.

After the silicon dioxide ceramic powder and the resin system are obtained, the silicon dioxide powder and the resin system are mixed to obtain the photocuring silicon dioxide ceramic slurry. The mixing method is not particularly limited in the present invention, and the mixing method known to those skilled in the art, such as stirring, may be adopted. In the invention, the stirring speed is preferably 350-450r/min, more preferably 375-425 r/min, and most preferably 400 r/min. In the invention, the stirring time is preferably 30-60 min, more preferably 35-55 min, and most preferably 40-50 min.

The invention also provides application of the photocuring ceramic slurry in the technical scheme in preparation of silicon dioxide ceramic parts.

Preferably, the application comprises the steps of:

(1) carrying out photocuring on the photocuring silica ceramic slurry with solid content to form a blank;

(2) and (2) sequentially degreasing and sintering the blank obtained in the step (1) to obtain the silicon dioxide ceramic part.

Preferably, the wavelength of the light source for photocuring in the step (1) is 365-450 nm.

The invention carries out photocuring on the photocuring silicon dioxide ceramic slurry to form a blank. In the present invention, the wavelength of the light source for photocuring is preferably 365 to 450nm, more preferably 380 to 420nm, and most preferably 390 to 410 nm. The number of photocuring times of the photocuring silica slurry is not limited, and can be adjusted by a person skilled in the art as required. In the invention, the time for each photocuring is preferably 4-10 s, more preferably 5-9 s, and still more preferably 6-8 s. In the present invention, the thickness of the photo-cured product after each photo-curing is preferably 0.02 to 0.05mm, more preferably 0.03 to 0.04mm, and most preferably 0.035 mm. The invention preferably carries out multiple curing on the photocuring silica ceramic slurry, improves the photocuring effect of the photocuring slurry, and can also prepare a blank with a more complex shape.

In the present invention, the photocuring is preferably performed in a photocuring apparatus according to a pre-designed pattern to obtain a green body. The present invention is not limited to the specific figures, and those skilled in the art can design the figures as required.

After the green body is obtained, the green body is sequentially degreased and sintered to obtain the hydroxyl apatite lime ceramic part. In the invention, the degreasing temperature is preferably 500-800 ℃, more preferably 600-700 ℃, most preferably 650-700 ℃, and the degreasing time is 60-120min, more preferably 60-90min, most preferably 80 min. In the present invention, the heating rate for heating to the degreasing temperature is preferably 0.5 to 2 ℃/min, more preferably 0.8 to 1.6 ℃/min, and most preferably 1.0 to 1.4 ℃/min. In the invention, the degreasing can remove the active diluent in the blank body.

In the present invention, the sintering pressure is preferably 0.2 to 0.5MPa, more preferably 0.3 to 0.4MPa, and most preferably 0.35 MPa. In the invention, the sintering temperature is preferably 1100-1250 ℃, more preferably 1150-1250 ℃, most preferably 1200-1250 ℃, and the sintering time is preferably 48-96h, more preferably 72-96h, most preferably 80 h. In the present invention, the sintering enables the silica part.

The invention has the beneficial effects that:

the photocuring silicon dioxide slurry provided by the invention has stable performance and good uniformity and dispersibility.

The silicon dioxide ceramic part prepared by the method has stable mechanical property, and the preparation method is simple, short in time consumption and low in cost.

Detailed Description

In order to more clearly and completely describe the technical scheme of the invention, the invention is further described in detail by the specific embodiments, and it should be understood that the specific embodiments described herein are only used for explaining the invention, and are not used for limiting the invention, and various changes can be made within the scope defined by the claims of the invention.

Examples 1 to 3 and comparative examples 1 to 3

A photocurable silica ceramic slurry comprising: mixing modified silicon dioxide powder, acrylic ester, a diluent and a photoinitiator according to a mass ratio;

the modified silicon dioxide powder is prepared by mixing silicon dioxide powder, a surface modifier and a dispersant according to a mass ratio.

In the examples and comparative examples, the amounts of the respective components were calculated in terms of mass ratios based on the silica powder.

The formulation of the modified silica powder is shown in table 1:

TABLE 1

The formulation of the photocurable silica ceramic slurry is shown in table 2: TABLE 2

A preparation method of photocuring silica ceramic slurry comprises the following steps:

(1) stirring the surface modifier, the diluent and the silicon dioxide powder on a planet ball mill, and then drying in a drying oven to obtain modified silicon dioxide powder; the parameters of stirring and drying are shown in Table 3;

(2) uniformly stirring acrylic ester, a diluent and a photoinitiator to obtain a resin system, wherein the specific stirring parameters are shown in table 3;

(3) and (3) taking 100 parts of modified silicon dioxide powder and stirring with a resin system to obtain the photocuring silicon dioxide slurry, wherein the stirring parameters are shown in table 3.

TABLE 3

The application of the photocuring silicon dioxide slurry in preparing silicon dioxide ceramics comprises the following steps; (1) carrying out photocuring on the photocuring silicon dioxide slurry to form a blank;

(2) and sequentially degreasing and sintering the obtained blank to obtain the silicon dioxide part.

Specific parameters of photocuring, degreasing and sintering are shown in table 4.

TABLE 4

The silica ceramics prepared in the above examples and comparative examples were tested by using a mechanical property test standard, and the silica ceramics had good mechanical properties. The test results are shown in table 5.

TABLE 5

Finally, it should be emphasized that the above-described preferred embodiments of the present invention are merely examples of implementations, rather than limitations, and that many variations and modifications of the invention are possible to those skilled in the art, without departing from the spirit and scope of the invention.

Claims

1. The photocuring silica ceramic slurry is characterized by being prepared by mixing modified silica powder, acrylate, a diluent and a photoinitiator according to a mass ratio of 10-100:1-60:1-60: 1-6;

2. The photocurable silica ceramic slurry according to claim 1, wherein the silica powder has a particle size of 50-800 nm; the acrylate includes epoxy acrylate.

3. The photocurable silica ceramic slurry according to claim 1, wherein the diluent is one or a mixture of 1, 6-hexanediol diacrylate, hydroxyethyl acrylate and trimethylolpropane triacrylate in any ratio.

4. The photocurable silica ceramic slurry according to claim 1, wherein the photoinitiator is one or a mixture of phenyl phosphorus dioxide and 1-hydroxycyclohexyl phenyl ketone in any proportion.

5. The photocurable alumina ceramic slurry as claimed in claim 1, wherein the surface modifier is any one or a mixture of KH550, KH570 and KH 592.

6. The photocurable alumina ceramic slurry according to claim 1, wherein the dispersant is one or more of KOS110, KOS190 and KOS 163.

7. A method for preparing a photocurable silica ceramic slurry according to any one of claims 1-6, comprising the steps of:

(1) stirring and ball-milling the acrylate, the diluent and the photoinitiator according to the mass ratio of 1-60:1-60:1-6 to obtain a resin system;

(2) stirring and ball-milling the silicon dioxide powder and the surface modifier according to the mass ratio of 10-80: 1-10; and then drying to finally obtain the dispersed tricalcium phosphate powder.

(3) And (3) mixing the silicon dioxide powder obtained in the step (2) with the resin system obtained in the step (1) to obtain the photocuring silicon dioxide ceramic slurry.

8. Use of the photocurable dioxyceramic slurry of any of claims 1-6 in the preparation of a silica material.

9. The use of the photocurable dioxyceramic slurry of claim 8 in the preparation of a silica material, comprising the steps of:

(1) carrying out photocuring on the photocuring silicon dioxide ceramic slurry to form a silicon dioxide ceramic blank;

(2) and (2) sequentially degreasing and sintering the blank obtained in the step (1) to obtain the gradient silicon dioxide ceramic part.

10. The use as claimed in claim 9, wherein the light source for photocuring in step (1) has a wavelength of 365 and 460 nm.