Photocuring additive manufacturing method suitable for bi-material layered ceramic

Abstract

The invention belongs to the technical field of 3D printing, and discloses a photocuring additive manufacturing method suitable for bi-material layered ceramic, and ceramic layers of the bi-material layered ceramic are silicon nitride ceramic and boron nitride ceramic respectively. The method comprises the following steps: preparing silicon nitride slurry, wherein the silicon nitride slurry is prepared from the following raw materials: silicon nitride powder, photosensitive resin, a sintering aid, a dispersing agent and a photoinitiator; preparing boron nitride slurry, wherein the boron nitride slurry is prepared from the following raw materials: boron nitride powder, aluminum oxide, boron oxide, photosensitive resin and a dispersing agent; putting the silicon nitride slurry and the boron nitride slurry into a 3D printer, and alternately printing silicon nitride ceramic and boron nitride ceramic to obtain the dual-material layered ceramic. The sample printed by the photocuring additive manufacturing method of the bi-material layered ceramic is firm in interlayer combination, does not crack after being sintered, and is suitable for preparation of various heterogeneous layered ceramic structures.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of additive manufacturing materials, and relates to a photocuring additive manufacturing method suitable for double-material layered ceramics. BACKGROUND

[0002] In the existing high-temperature-resistant material system, the silicon oxide fiber reinforced oxide ceramic and the aluminum oxide fiber reinforced oxide ceramic have insufficient temperature resistance; the silicon nitride fiber reinforced silicon nitride ceramic has high cost, and application thereof has great economic pressure; and the homogeneous silicon nitride ceramic has a temperature resistance of 1500 DEG C and low cost, but has low fracture toughness and is easy to be brittlely broken, so that safety and reliability thereof are low in the application process. In order to improve the brittleness of the ceramic material and improve the toughness thereof, a layered composite ceramic structure is prepared, the layered structure with alternating strong and weak layers prolongs the crack propagation path, and the reliability of the material is greatly improved.

[0003] Although the layered ceramic material has obvious advantages in strength and toughness, by using a traditional preparation method, only a simple flat plate sample can be prepared, and the micro-layered structure cannot be accurately controlled. The additive manufacturing technology is one of the most rapidly developed advanced automatic manufacturing technologies at present, and a three-dimensional sample is obtained through layer-by-layer stacking based on the "discrete-accumulation" principle. The additive manufacturing technology perfectly solves the problems faced by the traditional preparation process in the preparation of complex microstructure parts, and has wide development and application prospects. SUMMARY

[0004] The application aims to overcome the technical defects of the prior art, and provide a photocuring additive manufacturing method suitable for double-material layered ceramics, so as to solve the problems of difficult preparation of a double-material structure and sintering cracking in the prior art.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows: The application provides a photocuring additive manufacturing method suitable for double-material layered ceramics, the double-material ceramic is a silicon nitride ceramic and a boron nitride ceramic, and the method comprises the following steps: Preparation of a silicon nitride slurry, the silicon nitride slurry is prepared from the following raw materials: silicon nitride powder, photosensitive resin, sintering aid, dispersant and photoinitiator; Preparation of a boron nitride slurry, the boron nitride slurry is prepared from the following raw materials: boron nitride powder, aluminum oxide, boron oxide, photosensitive resin and dispersant; wherein the aluminum oxide and the boron oxide are used to improve the interlayer bonding strength with the silicon nitride layer; The silicon nitride slurry and the boron nitride slurry are placed in a 3D printer, and printing of the silicon nitride ceramic and the boron nitride ceramic is alternately performed, so that the double-material layered ceramic is obtained.

[0006] As a further scheme of the present application: the silicon nitride slurry is prepared from the following raw materials by volume fraction: silicon nitride powder 30-50 parts, photosensitive resin 35-60 parts, sintering aid 5-15 parts, dispersant 2.5-5 parts, and photoinitiator 0.5-1.5 parts; and the boron nitride slurry is prepared from the following raw materials by volume fraction: boron nitride powder 10-30 parts, aluminum oxide powder 3-10 parts, boron oxide powder 3-10 parts, photosensitive resin 60-80 parts, and dispersant 0.5-3 parts.

[0007] As a further scheme of the present application: the sintering aid comprises aluminum oxide, silicon dioxide, yttrium oxide, and boron nitride.

[0008] As a further scheme of the present application: the solid content of the silicon nitride ceramic slurry is 40-50%, and the solid content of the boron nitride ceramic slurry is 25-35%.

[0009] As a further scheme of the present application: the solid content of the silicon nitride slurry is one of 40%, 45%, and 50%, and the solid content of the boron nitride slurry is one of 25%, 30%, and 35%.

[0010] As a further scheme of the present application: the dispersant is BYK110.

[0011] As a further scheme of the present application: the photosensitive resin comprises photosensitive resin A and photosensitive resin B; the photosensitive resin A is at least one selected from the group consisting of hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, and propoxylated neopentyl glycol diacrylate; the photosensitive resin B is at least one selected from the group consisting of trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, and epoxy methacrylate; and the volume ratio of the photosensitive resin A to the photosensitive resin B is 1:1-1:4.

[0012] As a further scheme of the present application: the photoinitiator is selected from 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide.

[0013] As a further scheme of the present application: the printing parameters of the 3D printer comprise: printer LED light source wavelength 405 nm; resolution 30 microns; printing layer thickness 10-100 microns; light intensity 2-20 ; and exposure time per layer 2-50 s.

[0014] As a further scheme of the present application: the printing of the silicon nitride ceramic and the boron nitride ceramic is alternately performed, and specifically comprises: printing of a silicon nitride layer, with curing light intensity 10-20 , curing time 7-12 s, printing layer thickness 35-45 microns, and printing layer number 6-10 layers; Silicon nitride transition layer printing, curing light intensity is 10-20 , curing time is 7-12s, printing layer thickness is 15-25 microns, printing layer number is 1 layer, printing pattern is grid shape; Boron nitride layer printing, curing light intensity is 2-8 , curing time is 1-5s, printing layer thickness is 15-25 microns, printing layer number is 1 layer; Boron nitride transition layer printing, curing light intensity is 2-8 , curing time is 1-5s, printing layer thickness is 15-25 microns, printing layer number is 1 layer, printing pattern is grid shape. Repeat the process.

[0015] As a further scheme of the present application: the printing layer thickness of the silicon nitride layer is 40 microns, and the printing layer number is 8 layers; the printing layer thickness of the silicon nitride transition layer is 25 microns; the printing layer thickness of the boron nitride layer is 20 microns; and the printing layer thickness of the boron nitride transition layer is 25 microns.

[0016] As a further scheme of the present application: the transition layer is characterized in that the grid of the transition layer is composed of square cells of the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms, and when the light source is on at the cell, the photosensitive resin at this position is cured, and the pattern is solid; when the light source is off at the cell, the resin does not cure, and the pattern is hollow. The cells are staggered in the row and column directions, and the cell side length is 30-50 microns.

[0017] The present application also provides a double-material layered ceramic manufactured by the above method.

[0018] The present application has the following beneficial effects: The present application controls the curing thickness of the two ceramic slurries under different light intensities and curing times by selecting appropriate light curing parameters, and combines with the grid-shaped transition layer design, so that the problem of poor layer bonding and sintering cracking caused by the difference of ceramic layer materials does not occur in the 3D printing process of the multi-material layered structure. The light curing additive manufacturing method of the double-material layered ceramic of the present application has high interface bonding strength in the printing process, the transition layer embedding structure is firm, there is no sintering cracking phenomenon, and the component strength is high. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a transition layer structure diagram of the present application.

[0020] Figure 2 is an SEM image of a silicon nitride / boron nitride ceramic sample prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0021] The present application will be further described in detail below through specific embodiments and drawings.

[0022] Example 1 Step S1, take the solid content of 45% silicon nitride slurry and solid content of 30% boron nitride slurry, put into 405 nm wavelength 3D printer.

[0023] Step S2, silicon nitride ceramic layer printing, solidification light intensity is 16 , exposure time 10 s, print layer thickness 40 microns, print layer number 8 layers.

[0024] Step S3, silicon nitride ceramic transition layer printing, printing pattern is the same size square cell structure, arranged into a regular matrix. As Figure 1 shown, the cell alternately appears in solid and hollow two forms, and is staggered in row and column directions, the cell side length is 30 microns, solidification light intensity is 16 , exposure time 10 s, print layer thickness 25 microns, print layer number 1 layer.

[0025] Step S4, boron nitride ceramic layer printing, solidification light intensity is 5 , exposure time 3 s, print layer thickness 20 microns, print layer number 1 layer.

[0026] Step S5, boron nitride ceramic transition layer printing, printing pattern is the same size square cell structure, arranged into a regular matrix. The cell alternately appears in solid and hollow two forms. And is staggered in row and column directions, the cell side length is 30 microns, solidification light intensity is 5 , exposure time 3, print layer thickness 25 microns, print layer number 1 layer.

[0027] Step S6, repeat the above process, alternately complete the layered structure of 3D printed silicon nitride / boron nitride ceramic, the total thickness of silicon nitride layer is 345 microns, and the thickness of boron nitride layer is 45 microns.

[0028] The bending strength of the ceramic sample after printing and sintering is 245.14 MPa. The SEM image of the silicon nitride / boron nitride ceramic sample prepared in the embodiment is shown in Figure 2 .

[0029] Example 2 The difference from example 1 is that only the solid content of the silicon nitride slurry taken in step S1 is 50%.

[0030] The bending strength of the ceramic sample after printing and sintering is 274.65 MPa.

[0031] Example 3 The difference from example 1 is that only the solid content of the boron nitride slurry taken in step S1 is 35%.

[0032] The flexural strength of the printed ceramic sample after the removal of the binder and sintering is 194.45 MPa.

[0033] Example 4 The difference from Example 1 is that: Step S2, printing of the silicon nitride ceramic layer, the curing light intensity is 10 , the exposure time is 10 s, the printing layer thickness is 40 microns, and the printing layer number is 8. Step S3, printing of the silicon nitride ceramic transition layer, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are distributed alternately in the row and column directions. The cell side length is 30 microns, the curing light intensity is 10 , the exposure time is 10 s, the printing layer thickness is 25 microns, and the printing layer number is 1.

[0034] The flexural strength of the printed ceramic sample after the removal of the binder and sintering is 84.47 MPa.

[0035] Example 5 The difference from Example 1 is that: Step S2, printing of the silicon nitride ceramic layer, the curing light intensity is 20 , the exposure time is 10 s, the printing layer thickness is 40 microns, and the printing layer number is 8.

[0036] Step S3, printing of the silicon nitride ceramic transition layer, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are distributed alternately in the row and column directions. The cell side length is 30 microns, the curing light intensity is 20 , the exposure time is 10 s, the printing layer thickness is 25 microns, and the printing layer number is 1.

[0037] The flexural strength of the printed ceramic sample after the removal of the binder and sintering is 224.72 MPa.

[0038] Example 6 The difference from Example 1 is that: Step S4, printing of the boron nitride ceramic layer, the curing light intensity is 2 , the exposure time is 3 s, the printing layer thickness is 20 microns, and the printing layer number is 1.

[0039] Step S5, printing of the boron nitride ceramic transition layer, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are distributed alternately in the row and column directions. The cell side length is 30 microns, the curing light intensity is 2 , exposure time 3s, printing layer thickness 25 microns, printing layer number 1 layer.

[0040] The bending strength of the printed ceramic sample after the removal of the adhesive and sintering was 42.45 MPa.

[0041] Example 7: The difference from Example 1 is that: Step S4, boron nitride ceramic layer printing, solidification light intensity 8 , exposure time 3s, printing layer thickness 20 microns, printing layer number 1 layer; Step S5, boron nitride ceramic transition layer printing, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are distributed alternately in the row and column directions. The cell side length is 30 microns, the solidification light intensity is 8 , exposure time 3, printing layer thickness 25 microns, printing layer number 1 layer.

[0042] The bending strength of the printed ceramic sample after the removal of the adhesive and sintering was 172.56 MPa.

[0043] Example 8: The difference from Example 1 is that: Step S3, silicon nitride ceramic transition layer printing, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are distributed alternately in the row and column directions. The cell side length is 50 microns, the solidification light intensity is 16 , exposure time 10s, printing layer thickness 25 microns, printing layer number 1 layer.

[0044] Step S5, boron nitride ceramic transition layer printing, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are distributed alternately in the row and column directions. The cell side length is 50 microns, the solidification light intensity is 5 , exposure time 3, printing layer thickness 25 microns, printing layer number 1 layer.

[0045] The bending strength of the printed ceramic sample after the removal of the adhesive and sintering was 195.86 MPa.

[0046] Comparative Example 1: The difference from Example 1 is that there is no step S3 and step S5.

[0047] The bending strength of the printed ceramic sample after the removal of the adhesive and sintering was 23.46 MPa, and obvious interlayer separation phenomenon occurred.

[0048] Comparative Example 2: The difference from Example 1 is only that: Step S3, printing of the silicon nitride ceramic transition layer, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are staggered in the row and column directions. The cell side length is 50 microns, the curing light intensity is 16 , the exposure time is 10 s, the printing layer thickness is 50 microns, and the number of printed layers is 1.

[0049] Step S5, printing of the boron nitride ceramic transition layer, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are staggered in the row and column directions. The cell side length is 50 microns, the curing light intensity is 5 , the exposure time is 3, the printing layer thickness is 50 microns, and the number of printed layers is 1.

[0050] The bending strength of the printed ceramic sample after degreasing and sintering is 84.25 MPa.

[0051] Comparative Example 3: The difference from Example 1 is only that: Step S3, printing of the silicon nitride ceramic transition layer, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are staggered in the row and column directions. The cell side length is 500 microns, the curing light intensity is 16 , the exposure time is 10 s, the printing layer thickness is 50 microns, and the number of printed layers is 1.

[0052] Step S5, printing of the boron nitride ceramic transition layer, the printing pattern is composed of square cells with the same size, arranged in a regular matrix. The cells appear alternately in solid and hollow forms and are staggered in the row and column directions. The cell side length is 500 microns, the curing light intensity is 5 , the exposure time is 3, the printing layer thickness is 50 microns, and the number of printed layers is 1.

[0053] The bending strength of the printed ceramic sample after degreasing and sintering is 206.54 MPa.

[0054] The specific embodiments of the present application disclosed above are intended to help understand the content of the present application and to implement the same, and those skilled in the art can understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present application. The present application should not be limited to the content disclosed in the examples of the present application, and the protection scope of the present application is defined by the scope of the claims.

Claims

1. A photocurable additive manufacturing method suitable for bimaterial layered ceramics, characterized in that, Includes the following steps: A silicon nitride slurry is prepared from the following raw materials: silicon nitride powder, photosensitive resin, sintering aid, dispersant, and photoinitiator; A boron nitride slurry is prepared from the following raw materials: boron nitride powder, alumina, boron oxide, photosensitive resin, and dispersant; Silicon nitride slurry and boron nitride slurry are placed into a 3D printer, and silicon nitride ceramic and boron nitride ceramic are printed alternately to obtain a two-material layered ceramic.

2. The method according to claim 1, characterized in that, The solid content of the silicon nitride ceramic slurry is 40-50%; the solid content of the boron nitride ceramic slurry is 25-35%.

3. The method according to claim 1, characterized in that, The photosensitive resin includes photosensitive resin A and photosensitive resin B; photosensitive resin A is selected from at least one of hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, and propoxylated neopentyl glycol diacrylate; photosensitive resin B is selected from at least one of trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, and epoxy methacrylate; the volume ratio of photosensitive resin A to photosensitive resin B is 1:1 to 1:

4.

4. The method according to claim 1, characterized in that, The photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

5. The method according to claim 1, characterized in that, The printing parameters of the 3D printer include: LED light source wavelength of 405nm; resolution of 30 micrometers; printing layer thickness of 10-100 micrometers; and light intensity of 2-20. Exposure time for each layer is 2-50 seconds.

6. The method according to claim 1, characterized in that, The alternating printing of silicon nitride ceramics and boron nitride ceramics includes: Silicon nitride layer printing, curing light intensity 10-20 The curing time is 7-12 seconds, the printing layer thickness is 35-45 micrometers, and the number of printing layers is 6-10. Silicon nitride transition layer printing, curing light intensity 10-20 The curing time is 7-12 seconds, the printing layer thickness is 15-25 micrometers, the number of printing layers is 1, and the printing pattern is a grid. Boron nitride layer printing, curing light intensity 2-8 The curing time is 1-5 seconds, the printing layer thickness is 15-25 micrometers, and the number of printing layers is 1. Boron nitride transition layer printing, curing light intensity 2-8 The curing time is 1-5 seconds, the printing layer thickness is 15-25 micrometers, the number of printing layers is 1, and the printing pattern is a grid.

7. The method according to claim 6, characterized in that, The silicon nitride layer has a printing thickness of 40 micrometers and has 8 printing layers; the silicon nitride transition layer has a printing thickness of 25 micrometers; the boron nitride layer has a printing thickness of 20 micrometers; and the boron nitride transition layer has a printing thickness of 25 micrometers.

8. The method according to claim 1, characterized in that, The transition layer consists of square cells of identical size arranged in a regular matrix; the cells alternate between solid and hollow forms and are staggered in both row and column directions.

9. The method according to claim 8, characterized in that, The side length of the cell is 30-50 micrometers.

10. A bimaterial layered ceramic manufactured by the method according to any one of claims 1 to 9.

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