Forming device and preparation method of continuous fiber toughened ceramic wire

Abstract

The invention discloses a forming device and a preparation method of a continuous fiber toughened ceramic wire, and belongs to the technical field of additive manufacturing, and the preparation method comprises the following steps: firstly, carrying out ball milling on ceramic particles with different particle sizes and a dispersing agent to obtain ceramic powder; adding a shaping auxiliary material into the ceramic powder, and homogenizing to form ceramic coating slurry; the continuous fibers and the ceramic coating slurry are co-extruded, and after solidification, the continuous fiber toughened ceramic wire for additive manufacturing is obtained; according to the continuous fiber-ceramic integrated wire formed through the method, the forming difficulty of a continuous fiber toughened ceramic composite material is greatly reduced, and the problems that an existing additive manufacturing ceramic part is not ideal in mechanical property, and a continuous fiber toughened ceramic material is complex in structure and difficult to form are solved.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and in particular to a molding device and a preparation method of a continuous fiber-reinforced ceramic wire. Background Art

[0002] Continuous fiber reinforced ceramic matrix composites are a new type of strategic heat-resistant structural material. The crack deflection, interface debonding and fiber bridging mechanisms brought by continuous fibers when loaded make it have the advantages of high hardness, low density, high thermal conductivity, stable chemical properties, excellent high temperature strength and corrosion resistance. It has been widely used in aerospace, nuclear energy and other fields.

[0003] At present, the molding of continuous fiber-reinforced ceramic-based composites mainly relies on traditional processes such as reactive melt infiltration, chemical vapor infiltration, and fiber weaving technology, which are costly, difficult to process, and difficult to achieve complex structure molding; and the existing additive manufacturing methods such as direct writing molding and fused deposition molding are difficult to directly achieve the molding of continuous fiber-reinforced ceramic composites. These problems have seriously hindered the widespread application of continuous fiber ceramic composites. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a molding device and a preparation method for continuous fiber-reinforced ceramic wires, which introduce continuous fibers into thermoplastic ceramic wires to facilitate additive manufacturing, greatly reducing the difficulty of the continuous fiber ceramic composite material molding process.

[0005] The present invention is achieved through the following technical solutions: In a first aspect, the present application proposes a method for preparing a continuous fiber-reinforced ceramic wire, comprising the following steps: The ceramic powders with different particle sizes are prepared in proportion, mixed with a dispersant and then ball-milled to obtain a graded mixed ceramic powder; The liquid plastic material is homogenized with the graded mixed ceramic powder under vacuum to obtain a ceramic slurry; The ceramic slurry is uniformly coated on the continuous fiber and compacted and solidified to obtain the continuous fiber toughened ceramic wire.

[0006] Preferably, the ceramic powder is one or more of silicon carbide, silicon nitride, aluminum oxide, zirconium diboride, and hafnium diboride.

[0007] Preferably, the shaping material is a thermoplastic or thermosetting material; The thermoplastic material includes one or more of polyethylene glycol, polycaprolactone, polyvinyl butyral, polymethyl methacrylate, etc.; The thermosetting material includes one or more of phenolic resin, urea-formaldehyde resin, epoxy resin and the like.

[0008] Preferably, a ceramic slurry made of thermoplastic material is used, the ceramic slurry is coated on the continuous fibers, and then compacted and cooled to solidify the ceramic slurry.

[0009] Preferably, a ceramic slurry made of a thermosetting material is used, the ceramic slurry is coated on the continuous fibers, and then compacted and heated to solidify the ceramic slurry.

[0010] Preferably, the mass ratio of the molding material to the ceramic powder is 1:(3-4).

[0011] Preferably, the continuous fiber is one of carbon fiber, silicon carbide fiber, silicon nitride fiber and alumina fiber.

[0012] In a second aspect, the present application proposes a molding device for realizing the preparation method of the continuous fiber-reinforced ceramic wire, comprising an extrusion device, a co-extrusion nozzle, a fiber conveying device, a wire pressing roller and a wire winding device; The co-extrusion nozzle is formed with a fiber hole for passing the continuous fiber, the extrusion device is used to pour the ceramic slurry, and the output end of the extrusion device is connected to the fiber hole so that the ceramic slurry is coated on the continuous fiber; The fiber delivery device is arranged at the input end of the co-extrusion nozzle and is used to input the continuous fibers into the fiber holes; The wire pressing roller and the wire winding device are sequentially arranged at the output end of the co-extrusion nozzle. The wire pressing roller is used to extrude the continuous fiber coated with the ceramic slurry, and the wire winding device is used to roll the continuous fiber toughened ceramic wire.

[0013] Preferably, the fiber conveying device is provided with a barrel thermostat for controlling the temperature of the ceramic slurry.

[0014] Preferably, wire thermostats are provided at both ends of the wire pressing roller for controlling the temperature of the continuous fibers coated with the ceramic slurry to solidify the ceramic slurry.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a method for preparing continuous fiber-reinforced ceramic wires, in which continuous fibers are introduced into thermoplastic ceramic wires for additive manufacturing, thereby greatly reducing the difficulty of the continuous fiber-ceramic composite material molding process. The method realizes the preparation of continuous fiber-reinforced ceramic wires by co-extrusion of ceramic coating slurry and continuous fibers, and is compatible with existing wire additive manufacturing processes such as melt deposition, simplifies the molding steps of continuous fiber-reinforced ceramic composites, improves molding efficiency and molding effects, expands the application field of wire additive manufacturing, and solves the problem that complex structural parts of continuous fiber-reinforced ceramic composites are difficult to mold. The prepared continuous fiber-reinforced ceramic wires are core-shell structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of the molding device of the present invention.

[0017] In the figure: plunger mechanism 1, slurry barrel 2, barrel constant temperature device 3, co-extrusion nozzle 4, wire constant temperature device 5, fiber conveying device 6, wire pressing roller 7, wire winding device 8. DETAILED DESCRIPTION The present invention will be further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.

[0018] A method for preparing a continuous fiber-reinforced ceramic wire comprises the following steps: Step 1, preparing ceramic powder; The ceramic powders with different particle sizes are prepared in proportion, mixed with a dispersant and then ball-milled to obtain a graded mixed ceramic powder; The ceramic powder is one or more of silicon carbide, silicon nitride, aluminum oxide, zirconium diboride, and hafnium diboride, and the dispersant includes one or more of stearic acid, carboxyl stearic acid, and polyethylene glycol.

[0019] The particle size of the carbonized ceramic particles is 0.5-40 μm.

[0020] Step 2, preparing ceramic slurry; The liquid plastic material is homogenized with the graded mixed ceramic powder under vacuum to obtain a ceramic slurry; During the preparation of the ceramic slurry, the graded mixed ceramic powder is added in batches and homogenized with the liquid plastic material.

[0021] Thermoplastic auxiliary materials include one or more of polyethylene glycol, polycaprolactone, polyvinyl butyral, polymethyl methacrylate, etc.

[0022] Thermosetting auxiliary materials include one or more of phenolic resin, urea-formaldehyde resin, epoxy resin, etc.

[0023] The mass ratio of the molding material to the ceramic powder is 1:(3-4).

[0024] Step 3, preparing continuous fiber toughened ceramic wire; At a set temperature, the ceramic slurry is uniformly coated on the continuous fiber and compacted and solidified to obtain a continuous fiber-reinforced ceramic wire.

[0025] The continuous fiber is one of carbon fiber, silicon carbide fiber, silicon nitride fiber and aluminum oxide fiber.

[0026] It should be noted that the ceramic slurry prepared with thermoplastic auxiliary materials is solid at room temperature. The thermoplastic auxiliary materials are heated to a molten state and then homogenized with ceramic powder to form a ceramic slurry. The ceramic slurry is coated on the continuous fiber in a molten state, and solidified after compaction and cooling to obtain a continuous fiber-reinforced ceramic wire.

[0027] The ceramic slurry is prepared with thermosetting auxiliary materials. The thermosetting auxiliary materials are liquid at room temperature. They are directly homogenized with ceramic powder to form ceramic slurry. The ceramic slurry is coated on continuous fibers at room temperature, compacted and heated, and then solidified to obtain continuous fiber-reinforced ceramic wires.

[0028] This preparation method makes continuous fiber-toughened ceramic wires suitable for wire-type additive manufacturing processes. The introduction of continuous fibers gives the wires excellent mechanical properties. The formed continuous fiber-ceramic integrated wires greatly reduce the difficulty in forming continuous fiber-toughened ceramic composite materials, solving the current problems of unsatisfactory mechanical properties of additively manufactured ceramic parts and difficulty in forming complex structures of continuous fiber-toughened ceramic materials.

[0029] See also Figure 1 The present application also proposes a forming device for continuous fiber-reinforced ceramic wire, including a plunger mechanism 1, a slurry barrel 2, a barrel constant temperature device 3, a co-extrusion nozzle 4, a wire constant temperature device 5, a fiber conveying device 6, a wire pressing roller 7 and a wire winding device 8.

[0030] The slurry barrel 2 is a hollow structure with an extrusion nozzle at one end. The plunger mechanism 1 is installed in the slurry barrel 2. The slurry barrel 2 is used to pour ceramic slurry. The plunger mechanism 1 moves along the axial direction of the slurry barrel 2 to apply pressure to the coating slurry, so that the ceramic slurry flows out from the extrusion nozzle.

[0031] The barrel thermostat 3 is coated on the slurry barrel 2 and is used to control the temperature of the ceramic slurry inside it to keep it in a liquid state, that is, to control the temperature of the ceramic slurry at a set temperature so that it can flow out of the extrusion nozzle under the pressure of the plunger mechanism.

[0032] For the ceramic slurry prepared with thermoplastic auxiliary materials, the barrel thermostat 3 is used to heat the ceramic slurry to keep it in a molten state; for the ceramic slurry prepared with thermosetting auxiliary materials, the barrel thermostat 3 is used to control the temperature of the ceramic slurry to keep it in a fluid state, and the temperature is room temperature or below room temperature.

[0033] The plunger mechanism is connected to a driving device, which is used to enable the plunger mechanism to undergo axial displacement. The driving device is an electric push rod, a liquid structure or a linear mechanical mechanism. It should be noted that the driving device needs to be able to control the movement rate to control the output of the ceramic slurry.

[0034] The output end of the continuous fiber passes through the co-extrusion nozzle 4 and is connected to the wire winding device 8. A fiber hole for passing the continuous fiber is arranged at the center of the co-extrusion nozzle 4. The side wall of the co-extrusion nozzle 4 is connected to the extrusion nozzle of the slurry barrel. The extrusion nozzle is connected to the limiting hole, so that the ceramic slurry can be coated on the continuous fiber. After cooling, the continuous fiber coated with the ceramic slurry forms a continuous fiber-reinforced ceramic wire, and the continuous fiber-reinforced ceramic wire is wound on the wire winding device 8.

[0035] The wire winding device 8 includes a wire coil and a driving device. The driving device is connected to the pre-coil to control the pre-coil to rotate in a predetermined direction, and the continuous fiber-reinforced ceramic wire is wound on the wire coil. The driving device causes the wire coil to rotate at a certain speed.

[0036] The continuous fiber is input into the co-extrusion nozzle 4 through the fiber conveying device 6. The fiber conveying device 6 includes two rollers rotating relatively. The continuous fiber is located between the two rollers. During the manufacturing process of the continuous fiber-reinforced ceramic wire, the continuous fiber is always in a taut state.

[0037] A wire thermostat 5 and a wire pressing roller 7 are arranged between the co-extrusion nozzle 4 and the wire winding device 8. The wire thermostat 5 is arranged on the transmission path of the continuous fiber. The continuous fiber output by the co-extrusion nozzle 4 passes through the wire pressing roller 7 and is connected to the wire winding device 8.

[0038] The wire thermostat 5 is used to control the temperature of the continuous fiber coated with the ceramic slurry to solidify the ceramic slurry on the continuous fiber; the wire pressing roller 7 is used to extrude the continuous fiber to make the ceramic slurry and the continuous fiber fully contact.

[0039] When the ceramic slurry prepared with thermoplastic auxiliary materials is solidified, the ceramic slurry is cooled by the wire thermostat 5 to be solidified; when the ceramic slurry prepared with thermosetting auxiliary materials is solidified, the ceramic slurry is heated by the wire thermostat 5 to be solidified.

[0040] Example 1 A method for preparing a continuous fiber-reinforced ceramic wire comprises the following steps: Step 1, preparing ceramic powder; Silicon carbide ceramic particles with particle sizes of 40 μm, 10 μm, and 0.5 μm were ball-milled and mixed for grading. An appropriate amount of SA (stearic acid) was added to the graded ceramic particle powder as a dispersant, and the mixture was ball-milled for 1 h to obtain a ceramic powder, which was then placed in a 65 °C oven for later use.

[0041] Step 2, preparing ceramic slurry; Add PEG (polyethylene glycol) to a magnetic stirring water bath, heat the water bath to 65 °C, add thickener GG (guar gum) and stir for 10 min, add the ceramic powder prepared in step 1, and homogenize in a homogenizer at a constant temperature of 65 °C and at speeds of 800 r / min, 1400 r / min, and 1200 r / min for 90 min to obtain a ceramic slurry for coating continuous fibers.

[0042] Step 3, co-extrusion molding; Use a barrel thermostat to preheat the barrel to 65°C. Slowly add the ceramic slurry into the slurry barrel and shake it to remove the voids in the slurry. Make sure the liquid level on the slurry does not exceed 4 / 5 of the height of the slurry barrel to prevent overflow during shaking that may affect the operation of the plunger mechanism.

[0043] Step 4: Threading continuous fibers One end of the continuous fiber passes through the fiber conveying device 6 , the co-extrusion nozzle 4 and the wire pressing roller 7 in sequence, and then is connected to the wire winding device 8 .

[0044] Step 5: Start the plunger mechanism to extrude the slurry, drive the continuous fiber to be extruded synchronously, and after cooling, compact it through the wire pressing roller, and completely solidify it after cooling through the wire constant temperature device, thereby completing the preparation of the continuous fiber toughened ceramic wire.

[0045] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a continuous fiber-reinforced ceramic wire, characterized in that: The following steps are involved: The ceramic powders with different particle sizes are prepared in proportion, mixed with a dispersant and then ball-milled to obtain a graded mixed ceramic powder; The liquid plastic material is homogenized with the graded mixed ceramic powder under vacuum to obtain a ceramic slurry; The ceramic slurry is uniformly coated on the continuous fiber and compacted and solidified to obtain the continuous fiber toughened ceramic wire.

2. The method for preparing a continuous fiber-reinforced ceramic wire according to claim 1, characterized in that: The ceramic powder is one or more of silicon carbide, silicon nitride, aluminum oxide, zirconium diboride and hafnium diboride.

3. The method for preparing a continuous fiber-reinforced ceramic wire according to claim 1, characterized in that: The shaping material is a thermoplastic or thermosetting material; The thermoplastic material includes one or more of polyethylene glycol, polycaprolactone, polyvinyl butyral, polymethyl methacrylate, etc.; The thermosetting material includes one or more of phenolic resin, urea-formaldehyde resin, epoxy resin and the like.

4. The method for preparing a continuous fiber-reinforced ceramic wire according to claim 1, characterized in that: A ceramic slurry prepared from a thermoplastic material is coated on the continuous fiber, and then compacted and cooled to solidify the ceramic slurry.

5. The method for preparing a continuous fiber-reinforced ceramic wire according to claim 1, characterized in that: A ceramic slurry prepared from a thermosetting material is coated on continuous fibers, which are then compacted and heated to solidify the ceramic slurry.

6. The method for preparing a continuous fiber-reinforced ceramic wire according to claim 1, characterized in that: The mass ratio of the molding material to the ceramic powder is 1:(3-4).

7. The method for preparing a continuous fiber-reinforced ceramic wire according to claim 1, characterized in that: The continuous fiber is one of carbon fiber, silicon carbide fiber, silicon nitride fiber and aluminum oxide fiber.

8. A molding device for realizing the preparation method of the continuous fiber toughened ceramic wire material according to any one of claims 1 to 7, characterized in that: It includes an extrusion device, a co-extrusion nozzle, a fiber conveying device, a wire pressing roller and a wire winding device; The co-extrusion nozzle is formed with a fiber hole for passing the continuous fiber, the extrusion device is used to pour the ceramic slurry, and the output end of the extrusion device is connected to the fiber hole so that the ceramic slurry is coated on the continuous fiber; The fiber delivery device is arranged at the input end of the coextrusion nozzle and is used to input the continuous fibers into the fiber holes; The wire pressing roller and the wire winding device are sequentially arranged at the output end of the co-extrusion nozzle. The wire pressing roller is used to extrude the continuous fiber coated with the ceramic slurry, and the wire winding device is used to roll the continuous fiber toughened ceramic wire.

9. The forming device of continuous fiber-reinforced ceramic wire according to claim 8, characterized in that: The fiber conveying device is provided with a barrel thermostat for controlling the temperature of the ceramic slurry.

10. The forming device of continuous fiber-reinforced ceramic wire according to claim 8, characterized in that: Wire constant temperature devices are arranged at both ends of the wire pressing roller, which are used to control the temperature of the continuous fiber coated with the ceramic slurry to solidify the ceramic slurry.

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