Composite fiber / YSZ ceramic target material for EB-PVD and preparation method and application thereof
The composite fiber/YSZ ceramic target was prepared by gel casting method, which solved the complexity and cracking problems in the EB-PVD preparation process and achieved efficient and stable ceramic target preparation and improved thermal barrier coating performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-03-27
AI Technical Summary
Existing methods for preparing ceramic targets using electron beam physical vapor deposition (EB-PVD) are complex, costly, and difficult to achieve near-net-shape pressing. Furthermore, ceramic targets are prone to cracking, have insufficient stability in use, and the performance of thermal barrier coatings needs to be improved.
Composite fiber/YSZ ceramic targets were prepared by gel casting. By introducing rare earth oxide fibers and polymer fibers, combined with additives such as deionized water, acrylamide monomers, and crosslinking agents, one-step molding and high-temperature sintering were achieved to form a uniformly distributed linear pore and fiber structure, thereby enhancing the stability of the target material and the coating performance.
It significantly improves the efficiency of target preparation and service stability, reduces thermal conductivity, enhances the corrosion resistance and service life of the coating, and solves the problems of cracking and high cost in traditional methods.
Smart Images
Figure CN121735664A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of ceramic targets for electron beam physical vapor deposition, and in particular relates to a composite fiber / YSZ ceramic target for EB-PVD, its preparation method and application. Background Technology
[0002] Thermal barrier coatings (TBCs), as an effective way to reduce blade temperature and improve blade service life, have become a research hotspot in the international high-temperature coating field. Among all high-temperature resistant materials, TBCs play an irreplaceable role in improving the thermal efficiency and service life of engines, steam turbines, and turbines.
[0003] Currently, most TBC ceramic materials are zirconia-based ceramic coatings, which have advantages such as low thermal conductivity, high coefficient of thermal expansion, low elastic modulus, and good compatibility. As a coating, zirconia materials ensure effective thermal insulation without generating significant thermal stress during cold and hot cycles, preventing cracking or peeling failure and thus extending the coating's service life.
[0004] Electron beam physical vapor deposition (EB-PVD) technology produces coatings with high density, easily and precisely controlled chemical composition, and a columnar crystalline structure, resulting in stable performance and high thermal efficiency. The raw material for EB-PVD coatings is the ceramic target, and its quality directly determines the performance of the thermal barrier coating. To address the increasing demands for target materials, industrial production of targets needs to improve preparation efficiency, reduce production costs, ensure the stability of ceramic targets in use, and continuously improve the service life, thermal conductivity, and corrosion resistance of thermal barrier coatings.
[0005] Currently, the method for preparing ceramic targets for electron beam physical vapor deposition involves mixing raw material powder with a binder, granulating the mixture, and then performing pre-pressing, cold isostatic pressing, dimensional finishing, and sintering. This two-step pressing process is complex and cumbersome, requiring sophisticated equipment such as hydraulic presses and cold isostatic presses. Furthermore, the high maintenance costs of existing cold isostatic presses increase the cost of target preparation. The two-step pressing process also results in significant shrinkage, making near-net-shape pressing difficult. Dimensional finishing of the pressed target is necessary, further increasing preparation time and cost. Additionally, the raw material powder must be mixed with a binder during granulation, typically polyvinyl alcohol (PVA), which is prone to drying cracking, leading to target failure. Moreover, during service, the ceramic target is susceptible to cracking under the thermal stress of electron beam bombardment, indicating a need to improve its stability. Summary of the Invention
[0006] In view of this, the present invention aims to overcome the defects in the prior art and proposes a composite fiber / YSZ ceramic target for EB-PVD, its preparation method and application.
[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows: In a first aspect, the present invention provides a method for preparing a composite fiber / YSZ ceramic target for EB-PVD, comprising the following steps: Step 1: Mix and disperse deionized water, acrylamide monomers, and crosslinking agents to form a premixed liquid. Add dispersant, ammonia, YSZ raw material powder, rare earth oxide fibers, and polymer fibers to the premixed liquid and continue mixing and dispersing to obtain ceramic slurry. Step 2: Vacuum disperse the mixed ceramic slurry and stir to remove bubbles; Step 3: Add the initiator and catalyst to the defoamed ceramic slurry in sequence, continue stirring for 15-20 seconds and then stop stirring. Pour the ceramic slurry into the mold, let it stand to solidify and form, and obtain the target material blank. Step 4: After drying the target blank, the temperature is increased to dry it, and then the blank is removed and cooled to room temperature in the air for storage. Step 5: Sinter the dried target blank at 1400~1600℃ for 20~25h to obtain ceramic target material.
[0008] Preferably, the rare earth oxide fiber in step one is one or a mixture of two or more of the following: La2O3, Ta2O5, Er2O3, Tb2O3, CeO2, Lu2O3, Sc2O3, NbO2, Sm2O3, In2O3, and Yb2O3.
[0009] More preferably, the rare earth oxide fiber has a length of 3~15μm and a diameter of 0.05~0.2μm.
[0010] Preferably, the proportions of each component by weight are as follows: 5-15 parts deionized water, 1-5 parts acrylamide monomer, 0.02-0.2 parts crosslinking agent, 0.2-0.8 parts dispersant, 0.01-0.05 parts ammonia, 78.8-87 parts YSZ raw material powder, 1-5 parts rare earth oxide fiber, 0.2-1 part polymer fiber, 0.1-0.3 parts initiator, and 0.01-0.1 parts catalyst.
[0011] Preferably, the acrylamide monomer is one of acrylamide (AM), methacrylamide (MAM), and N,N-dimethylacrylamide (DMAA).
[0012] Preferably, the crosslinking agent is N,N-methylenebisacrylamide (MBAM).
[0013] Preferably, the dispersant is an isobam06 alkaline solution with a mass concentration of 10-30%.
[0014] Preferably, the yttrium oxide stabilizer content in the YSZ raw material powder is 6-9 wt%.
[0015] Preferably, the polymer fiber is PMMA fiber and / or PS fiber. More preferably, the polymer fiber has a diameter of 0.4~0.6μm and a length of 5~10μm.
[0016] Preferably, the initiator is ammonium persulfate.
[0017] Preferably, the catalyst is tetramethylethylenediamine.
[0018] Preferably, the dispersion and stirring time of the premixed liquid in step one is 1-2 hours; the dispersion and stirring time of the ceramic slurry is 2-4 hours, and the dispersion speed is 800-1300 rpm.
[0019] Preferably, in step two, the vacuum dispersion is performed at a vacuum level of -0.04 to -0.09 MPa, a rotation speed of 500 to 800 rpm, and stirring for 10 to 20 minutes.
[0020] Preferably, in step three, the mold is tilted at 45° so that the ceramic slurry is poured into the mold along the mold wall. The pouring process is accompanied by the mold returning to its original position, and the ceramic slurry is left to stand for 15-25 minutes to solidify and form.
[0021] Preferably, the drying process in step four is as follows: the room temperature is raised to 40°C and kept at that temperature for 4-8 hours; the temperature is raised to 80°C and kept at that temperature for 4-8 hours; the temperature is raised to 150°C and kept at that temperature for 4-8 hours.
[0022] Secondly, the present invention also provides a ceramic target material prepared by the above preparation method.
[0023] Thirdly, the present invention also provides the application of the above-mentioned ceramic target in the fields of electron beam physical vapor deposition and thermal barrier coating.
[0024] This invention utilizes gel casting to prepare ceramic targets for EB-PVD, using yttrium-stabilized zirconia as the main raw material, while introducing rare earth oxide fibers and polymer fibers, supplemented with deionized water, acrylamide monomers, crosslinking agents, dispersants, and other additives. The process involves one-step gel casting and final sintering to produce the ceramic target. The introduction of fibrous rare earth oxides, due to the use of a water-based gel casting method, allows for complete solid solution of the rare earth oxides with the yttrium-stabilized zirconia matrix, improving coating stability and corrosion resistance, reducing thermal conductivity, and maintaining a good fiber structure. The fiber pinning effect increases the fracture toughness of the target. The introduction of polymer fibers, after high-temperature sintering, leaves uniformly distributed linear pores within the ceramic target, dispersing stress. The combination of the two fiber types toughens the target, improving the stability of the green body while enabling stable evaporation even under significant temperature differences caused by electron beam bombardment during service. This method significantly improves the preparation efficiency, uniformity, service stability, and coating performance of the ceramic target, making it suitable for fields such as electron beam physical vapor deposition and high-performance thermal barrier coatings.
[0025] Compared with the prior art, the present invention has the following advantages: (1) This invention improves the stability of the target blank: Target preparation usually requires mixing powder with binder for granulation, and then pressing the granulated powder. The humidity of the granulated powder directly affects the pressing effect of the target. Excessive humidity will result in excessively high particle viscosity, reducing the fluidity of the powder during pressing and causing uneven density inside the target. Insufficient moisture content will result in low bonding force between powders, causing the blank to crack. The binder used in the granulation of raw material powder is usually polyvinyl alcohol (PVA). PVA molecular chains contain a large number of hydroxyl groups (-OH). These hydrophilic groups are prone to forming hydrogen bonds during the drying process, leading to crystallization or hardening on the material surface, thereby reducing viscosity. As a result, the pressed blank is prone to cracking during storage due to moisture evaporation, causing the target to be scrapped. This invention uses a gel casting method, which does not require the introduction of binder, thus avoiding cracking. At the same time, the addition of ceramic fibers and polymer fibers to the matrix can play a bridging role in the wet target, preventing cracking during the drying process. The liquid matrix and in-situ curing of gel casting promote the uniform distribution of ceramic particles inside the fiber and target material, reduce the density deviation inside the matrix, and also improve the stability of the wet and finished target material.
[0026] (2) Near-net-shape target preparation of the present invention: The traditional two-step pressing method for preparing targets has a large shrinkage during the process, making it difficult to press near-net-shape. It is necessary to perform dimensional finishing on the pressed target, which increases the preparation time and cost. This injection molding slurry has a very small volume change during the liquid-solid conversion process, and the shrinkage rate of the green body after solidification is small, which can achieve near-net-shape molding.
[0027] (3) In this invention, the composite toughening of ceramic fibers and internal linear pores improves the service stability of the target material: The interfacial interaction between rare earth oxide ceramic fibers and the ceramic matrix changes the crack propagation path, causing the crack to continuously bypass the fiber or pass through the interface between the fiber and the matrix during the propagation process, thereby consuming more energy and delaying the fracture process of the material. The linear pores (channels with a large aspect ratio) left by polymer fibers after high-temperature sintering of the ceramic target material will significantly change the crack propagation path: When the crack tip encounters the linear pore, due to the stress gradient at the interface between the pore and the ceramic matrix, the crack cannot directly pass through the pore and is forced to deflect along the long axis or edge of the pore. This deflection changes the crack propagation path from a "straight line" to a "broken line". At the same time, the linear pore can be regarded as a "stress buffer zone". When the stress is transmitted to the pore area, the pore allows the surrounding matrix to undergo small deformation, dispersing the concentrated stress to a larger area of the matrix, reducing the stress peak at the crack tip, and delaying the further propagation of the crack.
[0028] (4) This invention improves coating stability, reduces coating thermal conductivity, and enhances coating resistance to silicate environment deposits (CMAS) corrosion: different rare earth oxides regulate lattice distortion and defect density through ionic radius, thereby reducing the thermal conductivity of the thermal barrier coating; solid solution strengthening and grain boundary pinning stabilize phase structure and microstructure, thereby improving coating stability and lifespan; rare earth elements can preferentially react with CMAS to generate high melting point phases or dense layers, thereby improving the coating corrosion resistance, thus achieving a synergistic improvement in the comprehensive performance of YSZ thermal barrier coating. Attached Figure Description
[0029] Figure 1 For the density uniformity of ceramic target materials in Examples 1-3, samples were taken from the middle, upper, and lower target locations. Detailed Implementation
[0030] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0031] In this document, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0032] In this document, when values are described as ranges, it should be understood that such disclosure includes disclosure of all possible subranges within that range, as well as the specific numerical values falling within that range, regardless of whether the specific numerical value or specific subrange is explicitly specified.
[0033] In this article, the terms "multiple" or "more than" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.
[0034] In this document, the terms "preferred" and "more preferred" are used only to describe implementation methods or embodiments with better effects, and should be understood as not constituting a limitation on the scope of protection of this invention.
[0035] In this document, terms such as "further" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.
[0036] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.
[0037] In this document, the term "about" means a specified value of + / - 10%, preferably + / - 5%, and more preferably + / - 1%.
[0038] In this article, the terms “include,” “including,” “have,” “contain,” etc., are all open-ended terms, meaning that they include but are not limited to.
[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.
[0040] The present invention will be described in detail below with reference to embodiments.
[0041] Example 1 Step 1: Pour 12wt% deionized water into a dispersing mixer, add 2.5wt% monomer DMAA and 0.2wt% crosslinking agent MBAM, disperse for 2 hours until completely dissolved to form a premixed liquid; then add 0.8wt% isobam06 alkaline solution (10% concentration), 0.03wt% ammonia, 81.57wt% YSZ raw material powder, 2wt% Yb2O3 fiber, and 0.5wt% PMMA fiber in sequence, disperse at high speed for 4 hours until uniformly dispersed, with a dispersion speed of 800 rpm, to prepare a ceramic slurry.
[0042] Step 2: Transfer the mixed ceramic slurry into a vacuum dispersion mixer, stir to remove bubbles, vacuum degree -0.06MPa, speed 600rpm, stir for 10min.
[0043] Step 3: Add 0.3wt% ammonium persulfate initiator and 0.1wt% tetramethylethylenediamine catalyst to the defoamed ceramic slurry in sequence, continue stirring for 15s, stop stirring, and pour the ceramic slurry into the mold by tilting the mold at 45° so that the ceramic slurry is slowly poured into the mold along the mold wall. During the pouring process, the mold returns to the center. Let it stand for 15 minutes to solidify and form the ceramic slurry, thus obtaining the target blank.
[0044] Step 4: Place the target blank in a constant temperature and humidity chamber and dry for 15 hours. Then put it into an oven and dry it according to the following program: raise the room temperature to 40°C and keep it at that temperature for 5 hours; raise the room temperature to 80°C and keep it at that temperature for 5 hours; raise the room temperature to 150°C and keep it at that temperature for 5 hours. Then take out the blank and cool it to room temperature in the air before storing it.
[0045] Step 5: Sinter the dried target blank at 1400℃ for 20 hours to obtain the ceramic target material.
[0046] The density of the prepared ceramic target material is 3.71 g / cm³. 3 The upper, middle, and lower parts of the target (such as...) Figure 1 The density uniformity of the target (as shown) is 0.13%, and the specific fracture energy of the test target is 86.11 J / mm². 2 The higher the fracture energy, the higher the thermal stress that the material can withstand, and the better its thermal shock resistance. Thermal shock performance tests were conducted on the target material, and the target material cracked after 4 thermal shock cycles at 1450℃.
[0047] Example 2 Step 1: Pour 12wt% deionized water into a dispersing mixer, add 2.5wt% monomer MAM and 0.2wt% crosslinking agent MBAM, disperse for 2 hours until completely dissolved to form a premixed liquid; then add 0.8wt% isobam06 alkaline solution (10% concentration), 0.03wt% ammonia, 79.87wt% YSZ raw material powder, 4wt% Tb2O3 fiber and 0.2wt% PMMA fiber in sequence, disperse at high speed for 4 hours until uniformly dispersed, with a dispersion speed of 1000 rpm, to prepare a ceramic slurry.
[0048] Step 2: Transfer the mixed ceramic slurry into a vacuum dispersion mixer, stir to remove bubbles, vacuum degree -0.06MPa, speed 600rpm, stir for 10min.
[0049] Step 3: Add 0.3wt% ammonium persulfate initiator and 0.1wt% tetramethylethylenediamine catalyst to the defoamed ceramic slurry in sequence, continue stirring for 15s, stop stirring, and pour the ceramic slurry into the mold by tilting the mold at 45° so that the ceramic slurry is slowly poured into the mold along the mold wall. During the pouring process, the mold returns to the center. Let it stand for 20 minutes to solidify and form the ceramic slurry, thus obtaining the target green body.
[0050] Step 4: Place the target blank in a constant temperature and humidity chamber and dry for 15 hours. Then put it into an oven and dry it according to the following program: raise the room temperature to 40°C and keep it at that temperature for 5 hours; raise the room temperature to 80°C and keep it at that temperature for 5 hours; raise the room temperature to 150°C and keep it at that temperature for 5 hours. Then take out the blank and cool it to room temperature in the air before storing it.
[0051] Step 5: Sinter the dried target blank at 1500℃ for 20 hours to obtain the ceramic target material.
[0052] The density of the prepared ceramic target material is 3.85 g / cm³. 3 The density uniformity of the upper, middle, and lower parts of the target was 0.19%, and the specific fracture energy of the target was 90.51 J / mm². 2 Thermal shock performance tests were conducted on the target material. The target material cracked after five thermal shock cycles at 1450℃.
[0053] Example 3 Step 1: Pour 12wt% deionized water into a dispersing mixer, add 2.5wt% monomer MAM and 0.2wt% crosslinking agent MBAM, disperse for 2 hours until completely dissolved to form a premixed liquid; then add 0.8wt% isobam06 alkaline solution (10% concentration), 0.03wt% ammonia, 0.57wt% YSZ raw material powder, 3wt% Er2O3 fiber, and 0.5wt% PMMA fiber in sequence, disperse at high speed for 4 hours until uniformly dispersed, with a dispersion speed of 1000 rpm, to prepare a ceramic slurry.
[0054] Step 2: Transfer the mixed ceramic slurry into a vacuum dispersion mixer, stir to remove bubbles, vacuum degree -0.06MPa, speed 600rpm, stir for 10min.
[0055] Step 3: Add 0.3wt% ammonium persulfate initiator and 0.1wt% tetramethylethylenediamine catalyst to the defoamed ceramic slurry in sequence, continue stirring for 15s, stop stirring, and pour the ceramic slurry into the mold by tilting the mold at 45° so that the ceramic slurry is slowly poured into the mold along the mold wall. During the pouring process, the mold returns to the center. Let it stand for 20 minutes to solidify and form the ceramic slurry, thus obtaining the target green body.
[0056] Step 4: Place the target blank in a constant temperature and humidity chamber and dry for 15 hours. Then put it into an oven and dry it according to the following program: raise the room temperature to 40°C and keep it at that temperature for 5 hours; raise the room temperature to 80°C and keep it at that temperature for 5 hours; raise the room temperature to 150°C and keep it at that temperature for 5 hours. Then take out the blank and cool it to room temperature in the air before storing it.
[0057] Step 5: Sinter the dried target blank at 1600℃ for 25 hours to obtain the ceramic target material.
[0058] The density of the prepared ceramic target material was 4.11 g / cm³. 3 The density uniformity of the upper, middle, and lower parts of the target material was 0.16%, and the specific fracture energy of the target material was 92.25 J / mm². 2 Thermal shock performance tests were conducted on the target material. The target material cracked after five thermal shock cycles at 1450℃.
[0059] Comparative Example 1 Step 1: Pour 12wt% deionized water into a dispersing mixer, add 2.5wt% monomer MAM and 0.2wt% crosslinking agent MBAM, disperse for 2 hours until completely dissolved to form a premixed liquid; add 0.8wt% isobam06 alkaline solution (10% concentration of dispersant), 0.03wt% ammonia water, 81.07wt% YSZ raw material powder, and 3wt% La2O3 fiber in sequence, disperse at high speed for 4 hours until uniformly dispersed, with a dispersion speed of 1000 rpm, to prepare a ceramic slurry.
[0060] Step 2: Transfer the mixed ceramic slurry into a vacuum dispersion mixer, stir to remove bubbles, vacuum degree -0.06MPa, speed 600rpm, stir for 10min.
[0061] Step 3: Add 0.3wt% of ammonium persulfate initiator and 0.1wt% of tetramethylethylenediamine catalyst to the defoamed ceramic slurry in sequence, continue stirring for 15s, stop stirring, and pour the ceramic slurry into the mold by tilting the mold at 45° so that the ceramic slurry is slowly poured into the mold along the mold wall. During the pouring process, the mold returns to the center. Let it stand for 20 minutes to solidify and form the ceramic slurry, thus obtaining the target blank.
[0062] Step 4: Place the target blank in a constant temperature and humidity chamber and dry for 15 hours. Then put it into an oven and dry it according to the following program: raise the room temperature to 40°C and keep it at that temperature for 5 hours; raise the room temperature to 80°C and keep it at that temperature for 5 hours; raise the room temperature to 150°C and keep it at that temperature for 5 hours. Then take out the blank and cool it to room temperature in the air before storing it.
[0063] Step 5: Sinter the dried target blank at 1400℃ for 20 hours to obtain the ceramic target material.
[0064] The density of the prepared ceramic target material without linear pores was 4.56 g / cm³. 3 The specific fracture energy of the test target was 45.82 J / mm. 2 Because the target material is too dense, it lacks the space to disperse and buffer cracks caused by thermal stress. The target material was tested for thermal shock performance and cracked after one thermal shock cycle at 1450℃.
[0065] Comparative Example 2 Step 1: Pour 12wt% deionized water into a dispersing mixer, add 2.5wt% monomer DMAA and 0.2wt% crosslinking agent MBAM, disperse for 2 hours until completely dissolved to form a premixed liquid; then add 0.8wt% isobam06 alkaline solution (10% concentration), 0.03wt% ammonia, 83.57wt% YSZ raw material powder and 0.5wt% PMMA fiber in sequence, disperse at high speed for 4 hours until uniformly dispersed, with a dispersion speed of 800 rpm, to prepare a ceramic slurry.
[0066] Step 2: Transfer the mixed ceramic slurry into a vacuum dispersion mixer, stir to remove bubbles, vacuum degree -0.06MPa, speed 600rpm, stir for 10min.
[0067] Step 3: Add 0.3wt% ammonium persulfate initiator and 0.1wt% tetramethylethylenediamine catalyst to the defoamed ceramic slurry in sequence, continue stirring for 15s, stop stirring, and pour the ceramic slurry into the mold by tilting the mold at 45° so that the ceramic slurry is slowly poured into the mold along the mold wall. During the pouring process, the mold returns to the center. Let it stand for 15 minutes to solidify and form the ceramic slurry, thus obtaining the target green body.
[0068] Step 4: Place the target blank in a constant temperature and humidity chamber and dry for 15 hours. Then put it into an oven and dry it according to the following program: raise the room temperature to 40°C and keep it at that temperature for 5 hours; raise the room temperature to 80°C and keep it at that temperature for 5 hours; raise the room temperature to 150°C and keep it at that temperature for 5 hours. Then take out the blank and cool it to room temperature in the air before storing it.
[0069] Step 5: Sinter the dried target blank at 1400℃ for 20 hours to obtain the ceramic target material.
[0070] The density of the prepared ceramic target material is 3.68 g / cm³. 3 The density uniformity of the upper, middle, and lower parts of the target material was 0.12%, and the specific fracture energy of the target material was 41.85 J / mm². 2 Because no rare earth oxide fibers were added, the ceramic fiber bridging and the entanglement of the two fibers were lacking, resulting in a decrease in the overall stability of the target material. Thermal shock performance tests were conducted on the target material, and it cracked after two thermal shock cycles at 1450℃.
[0071] Comparative Example 3 Step 1: The ceramic target material is prepared by a two-step pressing method. 96wt% YSZ raw material powder, 3wt% La2O3 fiber, 0.5wt% PMMA fiber and deionized water are placed in a dispersing mixer and dispersed for 30 minutes at a stirring speed of 800 rpm. 0.5wt% PVA aqueous solution with a concentration of 5wt% is added as a binder to make ceramic slurry.
[0072] Step 2: Granulate the slurry using a spray granulator to obtain granulated powder with a moisture content of 5%.
[0073] Step 3: Pour the powder into the hydraulic press mold, pre-press it into shape, and then put the shaped target material into a cold isostatic press to press it into density, thus obtaining the target material blank.
[0074] Step 4: Sinter the target blank at 1400℃ for 20h to obtain zirconia-based ceramic target material.
[0075] The density of the dry-pressed ceramic target material prepared was 3.96 g / cm³. 3 The specific fracture energy of the test target was 27.01 J / mm. 2 Due to the influence of powder flowability and external force during dry pressing, the two fibers are prone to breakage and entanglement during the pressing process, resulting in reduced internal uniformity. The density uniformity of the upper, middle and lower parts of the target material is 1.65%. The target material was tested for thermal shock performance and cracked after one thermal shock cycle at 1450℃.
[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a composite fiber / YSZ ceramic target for EB-PVD, characterized in that: Includes the following steps: Step 1: Mix and disperse deionized water, acrylamide monomers, and crosslinking agents to form a premixed liquid. Add dispersant, ammonia, YSZ raw material powder, rare earth oxide fibers, and polymer fibers to the premixed liquid and continue mixing and dispersing to obtain ceramic slurry. Step 2: Vacuum disperse the mixed ceramic slurry and stir to remove bubbles; Step 3: Add the initiator and catalyst to the defoamed ceramic slurry in sequence, continue stirring for 15-20 seconds and then stop stirring. Pour the ceramic slurry into the mold, let it stand to solidify and form, and obtain the target material blank. Step 4: After drying the target blank, the temperature is increased to dry it, and then the blank is removed and cooled to room temperature in the air for storage. Step 5: Sinter the dried target blank at 1400~1600℃ for 20~25h to obtain ceramic target material.
2. The preparation method according to claim 1, characterized in that: In step one, the rare earth oxide fiber is made of one or more of the following materials: La2O3, Ta2O5, Er2O3, Tb2O3, CeO2, Lu2O3, Sc2O3, NbO2, Sm2O3, In2O3, and Yb2O3.
3. The preparation method according to claim 1, characterized in that: The rare earth oxide fibers have a length of 3~15μm and a diameter of 0.05~0.2μm.
4. The preparation method according to claim 1, characterized in that: The proportions of each component by weight are as follows: 5-15 parts deionized water, 1-5 parts acrylamide monomer, 0.02-0.2 parts crosslinking agent, 0.2-0.8 parts dispersant, 0.01-0.05 parts ammonia water, 78.8-87 parts YSZ raw material powder, 1-5 parts rare earth oxide fiber, 0.2-1 part polymer fiber, 0.1-0.3 parts initiator, and 0.01-0.1 parts catalyst.
5. The preparation method according to claim 1, characterized in that: The acrylamide monomer is one of acrylamide, methacrylamide, and N,N-dimethylacrylamide; Preferably, the crosslinking agent is N,N-methylenebisacrylamide; Preferably, the dispersant is an isobam06 alkaline solution with a mass concentration of 10-30 wt%; Preferably, the yttrium oxide stabilizer content in the YSZ raw material powder is 6-9 wt%.
6. The preparation method according to claim 1, characterized in that: The polymer fiber is PMMA fiber and / or PS fiber; more preferably, the polymer fiber has a diameter of 0.4~0.6μm and a length of 5~10μm.
7. The preparation method according to claim 1, characterized in that: The initiator is ammonium persulfate; Preferably, the catalyst is tetramethylethylenediamine.
8. The preparation method according to claim 1, characterized in that: The proportions of each component by weight are as follows: the dispersion and stirring time of the premixed liquid in step one is 1-2 hours; the dispersion and stirring time of the ceramic slurry is 2-4 hours, and the dispersion speed is 800-1300 rpm. Preferably, in step two, the vacuum degree of vacuum dispersion is -0.04 to -0.09 MPa, the rotation speed is 500 to 800 rpm, and the stirring time is 10 to 20 minutes; Preferably, in step three, the mold is tilted at 45° so that the ceramic slurry is poured into the mold along the mold wall. The pouring process is accompanied by the mold returning to its upright position. The ceramic slurry is left to stand for 15-25 minutes to solidify and form. Preferably, the drying process in step four is as follows: the room temperature is raised to 40°C and kept at that temperature for 4-8 hours; the room temperature is raised to 80°C and kept at that temperature for 4-8 hours; the room temperature is raised to 150°C and kept at that temperature for 4-8 hours.
9. The ceramic target material prepared by the preparation method according to any one of claims 1-8.
10. The application of the ceramic target material according to claim 9 in the fields of electron beam physical vapor deposition and thermal barrier coating.