1. A method for preparing a ceramic material by ultraviolet beam synchronous curing auxiliary direct-writing 3D printing is characterized by comprising the following steps:

step 1, establishing a three-dimensional model of a ceramic material and slicing the three-dimensional model;

step 2, preparing a glue dispenser needle cylinder and a needle head for containing the slurry in advance, and pushing air by using an air pump to extrude the slurry;

step 3, before printing begins, adjusting the laser irradiation position of an ultraviolet lamp on a printer moving platform to enable the irradiation point to coincide with the extrusion position of a sizing agent, wherein during printing, the point light source moves synchronously along with a printing needle head, initial curing and shaping are synchronously performed during printing, after single printing is completed, the printer stops printing, the needle head returns, the point light source of the ultraviolet lamp is closed, and a high-power ultraviolet lamp is turned on to perform surface exposure till complete curing;

step 4, the printer adjusts height parameters according to the height of the specific printing layer, continuously prints one or two layers on the solidified printing layer and exposes the solidified printing layer, and the operation is circulated until the printing is finished;

and 5, degreasing and sintering the printed and molded ceramic blank according to a sintering system.

2. The method for preparing the ceramic material through ultraviolet beam synchronous curing assisted direct-writing 3D printing according to claim 1, wherein the setting parameters of each printing layer in the step 1 are extrusion air pressure of 0.3-0.6MPa and printing speed of 4-10 mm/s.

3. The method for preparing the ceramic material through ultraviolet beam synchronous curing assisted direct-writing 3D printing according to claim 1, wherein the layer height of each printing layer in the step 1 is 0.6-1.2 times of the diameter of the selectable needle head.

4. The method for preparing a ceramic material through ultraviolet beam synchronous curing assisted direct-writing 3D printing according to claim 1, wherein in the step 4, after single printing, the defective part of the printing layer is inspected and repaired as appropriate, and when further printing is carried out after exposure, the printing height parameter is adjusted to be 0.9-1.2 layer height values according to the number of single printing layers.

5. The method for preparing the ceramic material through ultraviolet beam synchronous curing assisted direct-writing 3D printing according to claim 1, wherein in the step 4, after printing is completed, in order to ensure curing effect, integral exposure treatment is performed for a period of time.

Background

With the development of modern high and new technology industry, many industrial fields put higher demands on material properties. Advanced ceramics, as an important component of new materials, play an increasingly important role in national economy. Advanced ceramics, also known as high performance ceramics, are ceramics with excellent performance made from high purity, ultra-fine artificially synthesized or selected inorganic compounds as raw materials by compositional and structural design and by precise stoichiometry and novel preparation techniques. High hardness, high strength and high wear resistance are essential characteristics of ceramic materials, and by virtue of excellent physical properties, the ceramic materials are rapidly developed and widely applied in the fields of aerospace, electronic information, bioengineering and the like.

Meanwhile, due to the high hardness and high brittleness of the ceramic material, great inconvenience is brought to the manufacturing and processing of the ceramic parts, defects are easy to generate in the manufacturing process and difficult to compensate through subsequent treatment, and particularly the ceramic parts with complex structures are more difficult to form and process. At this time, the ceramic additive manufacturing technology is produced.

The additive manufacturing of the ceramic is actually to directly or indirectly carry out ceramic powder or slurry and the like by using additive manufacturing equipment

And (3) a molding technology. Direct processing techniques include the use of high energy beams (e.g., lasers) to selectively melt ceramic powders directly to achieve layer-by-layer formation

The ceramic slurry is subjected to three-dimensional photocuring or free extrusion molding to form a biscuit and the like. Efficiency of direct processing

Higher. The indirect processing process may employ a plurality of additive manufacturing processes, such as Selective Laser Sintering (SLS), direct die-less writing (DIW), stereo photo-curing (SLA), free extrusion molding (EFF), Digital Light Processing (DLP), etc., to manufacture ceramic green compacts from raw materials in the form of powder, slurry, mud compact, etc., and to realize the manufacture of ceramic parts through a subsequent sintering process. The direct writing forming is taken as a novel solid dieless forming technology, the concept of layered manufacturing of 3D printing is adopted, the processing and manufacturing of three-dimensional parts are completed through the accumulation of materials, the biggest advantage is that the forming is not limited by the traditional mould, the forming is simple, convenient and quick, and a ceramic blank with a porous or other complex structures can be manufactured, on the basis, if ultraviolet curing auxiliary forming is adopted, the curing time of the formed parts can be effectively shortened, the forming precision is improved, and the curing shrinkage rate is reduced, and in the ultraviolet light auxiliary direct writing forming process, if tracking exposure processing is carried out while printing, the problems of uneven curing, broken silk printing, local overexposure and the like caused by uneven exposure degree of each part are very easy to occur, and if a point light source is adopted for synchronous curing along with points, the existing small ultraviolet light source is insufficient in power and difficult to be completely cured, more seriously, in the whole printing process, cumulative problems such as structural collapse, edge warping and the like can directly cause the forming failure, thereby causing waste of time and cost.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for preparing a ceramic material by ultraviolet beam synchronous curing assisted direct-writing 3D printing, which can solve the problems of uneven curing, printing broken wires, local overexposure, accumulative defects and the like in a light-assisted direct-writing forming process.

The technical scheme adopted by the invention for solving the technical problems is as follows: a preparation method of a complex-structure ceramic material for ultraviolet beam synchronous curing assisted direct-writing 3D printing is constructed, and comprises the following steps:

step 1, establishing a proper three-dimensional model and slicing the three-dimensional model;

step 2, preparing a glue dispenser needle cylinder and a needle head for containing the slurry in advance, and pushing air by using an air pump to extrude the slurry;

step 3, before printing begins, adjusting the laser irradiation position of an ultraviolet lamp on a printer moving platform to enable the irradiation point to coincide with the extrusion position of the sizing agent, wherein during printing, the point light source moves synchronously along with a printing needle head, initial curing and shaping are synchronously performed during printing, after single printing is completed, the printer stops printing, the needle head returns, the point light source of the ultraviolet lamp is closed, the high-power ultraviolet lamp is opened to perform surface exposure till complete curing, and the exposure time depends on the solid content of the ceramic sizing agent;

and 4, the printer adjusts the height parameters according to the height of the specific printing layer, continuously prints one to two layers on the solidified printing layer and exposes the layers, and the operation is circulated until the printing is finished. After printing is finished, in order to ensure the curing effect, integral exposure treatment can be carried out for a period of time.

And 5, degreasing and sintering the printed and molded ceramic blank according to a sintering system.

In the method, the setting parameters of each printing layer in the step 1 are that the extrusion air pressure is 0.3-0.6MPa, and the printing speed is 4-10 mm/s.

In the method, the layer height in the step 1 is determined according to the selected needle diameter, and the layer height can be 0.6-1.2 times of the needle diameter, so that the problems of uneven exposure and printing dragging are avoided.

In the method, the filling pattern, the layer height and the filling rate of each printing layer in the step 1 can not be completely consistent.

In the method, in the step 4, after single printing, the defect part of the printing layer can be checked and repaired as appropriate, and when the printing layer is further printed after exposure, the printing height parameter is adjusted to be 0.9-1.2 layer height values according to the number of the single printing layers, so that the phenomena of material dividing and material dragging are prevented.

In the method, different kinds of ceramic blanks are subjected to degreasing sintering according to the corresponding sintering systems.

The method for preparing the ceramic material by the ultraviolet beam synchronous curing auxiliary direct-writing 3D printing has the following beneficial effects:

1. according to the invention, the ultraviolet light synchronous curing auxiliary direct-writing 3D printing ceramic adopting the point-by-point layer-by-layer composite irradiation mode can solve the problems of uneven curing, printing broken wires, local overexposure, insufficient power of a small point light source, accumulative defects in integral printing and the like in the conventional die-free direct-writing and ultraviolet light auxiliary direct-writing forming process. Meanwhile, the gradient materials with different printing layer parameters such as shape, filling pattern, filling density and the like can be formed more simply, conveniently, quickly and accurately.

2. The method provided by the invention has simple steps, has strong applicability to the viscosity, the fluidity and the like of printing materials, does not need expensive forming equipment, and can be used for preparing the ceramic blank which is fast and uniform in curing, good in setting property and small in curing shrinkage rate, the local defects of a single printing layer are relatively easy to repair, and the wire breakage problem in tracking printing and the accumulative defects such as collapse, edge warping and the like in integral printing can be avoided. In addition, the method combines the advantages of direct-writing printing, can quickly and simply prepare ceramic materials with complicated structures, personalized structures, multiple materials and the like according to preset design, is easy to popularize, and has wide application prospect.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a flow chart of a method for preparing a ceramic material by ultraviolet beam synchronous curing assisted direct-write 3D printing according to the present invention;

FIG. 2 is a schematic diagram of a printing apparatus used in the method for preparing ceramic material by ultraviolet beam synchronous curing assisted direct-write 3D printing according to the present invention;

fig. 3 is a schematic illustration of gradient materials of varying packing densities that may be used with the present invention.

Detailed Description

For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

Example 1

The method for preparing the ceramic material by the ultraviolet beam synchronous curing auxiliary direct-writing 3D printing comprises the following steps:

step 1, establishing a simple cubic three-dimensional model, slicing the three-dimensional model to obtain a series of two-dimensional section slices, setting the layer height to be 0.8mm, and filling patterns to be grid structures with the filling rate of 80%;

step 2, preparing a glue dispenser syringe and a needle head for containing slurry in advance, wherein the diameter of the needle head is 0.8mm, the slurry comprises about 80 wt% of BTO ceramic base material, about 20 wt% of PEGDA photosensitive resin, about 0.6 wt% of photoinitiator TPO and about 1.6 wt% of triton;

step 3, according to the setting in the step 1, turning on the movable point light source, enabling the point light source to move synchronously along with the printing needle head, synchronously performing initial curing and shaping during printing, printing a single-layer grid structure once, pausing printing after printing is finished, performing surface exposure by using a high-power ultraviolet lamp after the printing needle head is reset, and curing the printing layer for 1 minute;

step 4, according to the setting in the step 1, the printer adjusts the height parameter, the height direction is adjusted upwards by 1.0mm, the single-layer grid structure is continuously printed on the solidified printing layer and exposed, the process is circulated until the printing is finished, and the whole exposure can be selected for 3 minutes after the printing is finished;

and 5, setting the glue discharging process of the blank body in the nitrogen atmosphere to be at a heating rate of 0.5 ℃/min, and keeping the temperature for 1h at 300 ℃, 400 ℃, 450, 500, 600 and 700 ℃ respectively during the period to fully convert the organic matters into carbon, cooling along with the furnace, then moving into the air atmosphere to heat at 1 ℃/min, keeping the temperature for 2h at 400 ℃, 600 and 800 ℃ during the period, and removing the carbon. Finally, the temperature is raised to 1330 ℃ at the speed of 3 ℃/min and the ceramic component is prepared after sintering for 2 h.

Example 2

The method for preparing the ceramic material by the ultraviolet beam synchronous curing auxiliary direct-writing 3D printing comprises the following steps:

step 1, establishing a simple cubic three-dimensional model; slicing the three-dimensional model to obtain a series of two-dimensional section slices, wherein the height of a set layer is 0.4mm, a filling pattern is of a grid structure, and the filling rate is 100%;

step 2, preparing a glue dispenser syringe and a needle head for containing slurry in advance, wherein the diameter of the needle head is 0.8mm, the slurry comprises about 80 wt% of BTO ceramic base material, about 20 wt% of PEGDA photosensitive resin, about 0.6 wt% of photoinitiator TPO and about 1.6 wt% of triton;

step 3, opening the point light source according to the setting in the step 1, enabling the point light source to move synchronously along with the printing needle head, synchronously performing initial curing and shaping during printing, printing a single-layer grid structure, pausing printing after printing is finished, starting ultraviolet exposure after the printing needle head is reset, and curing the printing layer for 2 minutes;

step 4, according to the setting in the step 1, the printer adjusts the height parameter, the height direction is adjusted upwards by 0.5mm, the single-layer grid structure is continuously printed on the solidified printing layer and exposed, the process is circulated until the printing is finished, and the whole exposure can be selected for 3 minutes after the printing is finished;

and 5, setting the glue discharging process of the blank body in the nitrogen atmosphere to be at a heating rate of 0.5 ℃/min, and keeping the temperature for 1h at 300 ℃, 400 ℃, 450, 500, 600 and 700 ℃ respectively during the period to fully convert the organic matters into carbon, cooling along with the furnace, then moving into the air atmosphere to heat at 1 ℃/min, keeping the temperature for 2h at 400 ℃, 600 and 800 ℃ during the period, and removing the carbon. Finally, the temperature is raised to 1330 ℃ at the speed of 3 ℃/min and the ceramic component is prepared after sintering for 2 h.

Example 3

The method for preparing the ceramic material by the ultraviolet beam synchronous curing auxiliary direct-writing 3D printing comprises the following steps:

step 1, establishing a simple cubic three-dimensional model, and slicing the three-dimensional model to obtain a series of two-dimensional section slices, wherein the height of a set layer is 0.8mm, a filling pattern is zigzag, and the filling rate is 50%;

step 2, preparing a glue dispenser syringe and a needle head for containing slurry in advance, wherein the diameter of the needle head is 0.8mm, the slurry comprises about 80 wt% of BTO ceramic base material, about 20 wt% of PEGDA photosensitive resin, about 0.6 wt% of photoinitiator TPO and about 1.6 wt% of triton;

step 3, according to the setting in the step 1, turning on the movable point light source, enabling the point light source to move synchronously along with the printing needle head, synchronously performing initial curing and shaping during printing, printing the double-layer crossed sawtooth structure once, pausing printing after printing is finished, starting ultraviolet exposure after the printing needle head is reset, and curing the printing layer for 3 minutes;

step 4, according to the setting in the step 1, the printer adjusts the height parameter, the height direction is adjusted upwards by 1.7mm, the single-layer grid structure is continuously printed on the solidified printing layer and exposed, the process is circulated until the printing is finished, and the whole exposure can be selected for 3 minutes after the printing is finished;

and 5, setting the glue discharging process of the blank body in the nitrogen atmosphere to be at a heating rate of 0.5 ℃/min, and keeping the temperature for 1h at 300 ℃, 400 ℃, 450, 500, 600 and 700 ℃ respectively during the period to fully convert the organic matters into carbon, cooling along with the furnace, then moving into the air atmosphere to heat at 1 ℃/min, keeping the temperature for 2h at 400 ℃, 600 and 800 ℃ during the period, and removing the carbon. Finally, the temperature is raised to 1330 ℃ at the speed of 3 ℃/min and the ceramic component is prepared after sintering for 2 h.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.