WO2022166598A1 - 一种氮化硅基复相导电陶瓷的制备方法 - Google Patents

一种氮化硅基复相导电陶瓷的制备方法 Download PDF

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WO2022166598A1
WO2022166598A1 PCT/CN2022/072864 CN2022072864W WO2022166598A1 WO 2022166598 A1 WO2022166598 A1 WO 2022166598A1 CN 2022072864 W CN2022072864 W CN 2022072864W WO 2022166598 A1 WO2022166598 A1 WO 2022166598A1
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silicon nitride
preparation
temperature
sintering
microwave sintering
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PCT/CN2022/072864
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English (en)
French (fr)
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张伟儒
张晶
孙峰
董廷霞
李泽坤
李洪浩
徐金梦
荆赫
吕沛远
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中材高新氮化物陶瓷有限公司
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Definitions

  • the invention relates to the technical field of conductive ceramics, in particular to a preparation method of silicon nitride-based complex-phase conductive ceramics.
  • Silicon nitride ceramics have excellent comprehensive mechanical properties, especially the advantages of high strength, high hardness, high toughness and good wear resistance, and have high chemical stability and thermal shock resistance. It is an ideal engineering ceramics Materials, widely used in machinery, chemical industry, aerospace and national defense and other fields. However, due to the electrical insulating properties of silicon nitride ceramics, traditional diamond tools can only be used for mechanical processing. The processing efficiency is low, the cost is high, and it cannot be processed into parts with complex shapes, which severely limits the application of silicon nitride ceramics.
  • the conductivity of silicon nitride ceramics can be improved by introducing conductive phases such as titanium-based compounds (TiN, TiC, TiCN, TiB 2 ), zirconium-based compounds (ZrN, ZrC, ZrB 2 ) or MoSi 2 into silicon nitride ceramics. Furthermore, electrical discharge machining can be used, which improves the machining efficiency and solves the above-mentioned problem that parts with complex shapes cannot be machined.
  • conductive phases such as titanium-based compounds (TiN, TiC, TiCN, TiB 2 ), zirconium-based compounds (ZrN, ZrC, ZrB 2 ) or MoSi 2 into silicon nitride ceramics.
  • electrical discharge machining can be used, which improves the machining efficiency and solves the above-mentioned problem that parts with complex shapes cannot be machined.
  • the purpose of the present invention is to provide a preparation method of silicon nitride-based composite conductive ceramics.
  • the preparation method provided by the present invention can suppress the migration of grain boundaries, and utilize grain boundary diffusion to densify the green body, thus improving the nitriding effect.
  • the invention provides a preparation method of silicon nitride-based complex-phase conductive ceramics, comprising the following steps:
  • the sintering aid includes rare earth oxides and metal oxides, and the metal oxides include alumina or magnesia;
  • the mass content of silicon nitride is 40-60%
  • the mass content of the conductive phase is 30-50%
  • the mass content of the metal oxide is 1-5%
  • the rare earth oxide is The mass content of the material is 2-10%.
  • the conductive phase includes TiN, TiC, TiCN, TiB 2 , ZrN, ZrC, ZrB 2 or MoSi 2 .
  • the rare earth oxide includes yttrium oxide, lanthanum oxide or cerium oxide.
  • the mass content of ⁇ -Si 3 N 4 in the silicon nitride is ⁇ 85%.
  • the average particle size D50 of the silicon nitride is less than or equal to 1.0 ⁇ m.
  • the raw material of the green body in the step (1) further includes a microwave absorbent.
  • the microwave absorber comprises silicon carbide or zirconia.
  • the molding method in the step (1) includes one or more of dry pressing, cold isostatic pressing, injection molding, coagulation and grouting.
  • the temperature of the high-temperature microwave sintering is 1500-1700° C.
  • the holding time of the high-temperature microwave sintering is 0-30 min.
  • the temperature of the low-temperature microwave sintering is 1400-1600° C.
  • the holding time of the low-temperature microwave sintering is 10-120 mim.
  • the temperature difference between the high temperature microwave sintering and the low temperature microwave sintering is 50-150°C.
  • the heating rate of the high-temperature microwave sintering in the step (2) is 2 ⁇ 30° C./min.
  • the cooling rate of cooling to the temperature of the low-temperature microwave sintering after the high-temperature microwave sintering is 30-80° C./min.
  • both the high-temperature microwave sintering and the low-temperature microwave sintering in the step (2) are performed in a nitrogen atmosphere, and the flow rate of the nitrogen gas is independently 0.5-5 L/min.
  • the invention provides a method for preparing a silicon nitride-based complex-phase conductive ceramic, which comprises the following steps: mixing silicon nitride, a conductive phase and a sintering aid, and then molding to obtain a green body; sequentially subjecting the green body to high temperature Microwave sintering and low-temperature microwave sintering are used to obtain silicon nitride-based complex-phase conductive ceramics; the sintering aids include rare earth oxides and metal oxides, and the metal oxides include aluminum oxide or magnesium oxide.
  • the present invention uses silicon nitride as a matrix, adds a conductive phase and a sintering aid at the same time, and adopts a two-step microwave sintering method to prepare a silicon nitride-based complex-phase conductive ceramic with fine and uniform crystal grains, high density, and high strength, hardness, etc. Mechanical properties have also been significantly improved.
  • a continuous conductive network is formed in the silicon nitride matrix by adding a conductive phase, so as to improve the conductivity of the silicon nitride based ceramics, and the conductive phase has a stronger ability to absorb microwaves than the silicon nitride matrix, and can effectively improve the microwave sintering.
  • the two-step microwave sintering method adopted in the present invention can inhibit the grain boundary migration, and utilize the grain boundary diffusion to densify the green body; therefore, the method can not only inhibit the growth of crystal grains in the later stage of sintering, but will not affect the densification process. conduct.
  • the relative density of the silicon nitride-based complex phase conductive ceramic provided by the present invention is greater than 99%, the Vickers hardness is greater than 15GPa, the fracture toughness is greater than 6MPa ⁇ m 1/2 , the flexural strength is greater than 900MPa, and the resistivity is less than 1 ⁇ cm.
  • FIG. 1 is a schematic view of the microstructure of the silicon nitride-based complex-phase conductive ceramics prepared in Examples 1-4 and Comparative Examples 1-4 of the present invention
  • Fig. 2 is the schematic diagram of the microwave sintering furnace adopted in the present invention.
  • 1- alumina fiber furnace 2- temperature measuring device, 3- crucible, 4- silicon carbide, 5- green body to be sintered.
  • the invention provides a preparation method of silicon nitride-based complex-phase conductive ceramics, comprising the following steps:
  • the sintering aid includes rare earth oxides and metal oxides, and the metal oxides include aluminum oxide or magnesium oxide;
  • the silicon nitride, the conductive phase and the sintering aid are mixed and then shaped to obtain a green body.
  • the mass content of silicon nitride in the green body is preferably 40-60%, more preferably 45-55%.
  • the mass content of ⁇ -Si 3 N 4 in the silicon nitride is preferably ⁇ 85%, more preferably ⁇ 95%.
  • the average particle size D50 of the silicon nitride is preferably ⁇ 1.0 ⁇ m.
  • the average particle size of the silicon nitride in the above-mentioned range, so that when the average particle size of the silicon nitride is too large, sintering and densification can be prevented from being hindered, and the sintering temperature can be increased.
  • the source of the silicon nitride is not particularly limited in the present invention, and commercially available products well known to those skilled in the art can be used.
  • the mass content of the conductive phase in the green body is preferably 30-50%, more preferably 30-45%.
  • the conductive phase preferably includes TiN, TiC, TiCN, TiB 2 , ZrN, ZrC, ZrB 2 or MoSi 2 , more preferably TiN, TiC, ZrC or MoSi 2 .
  • a continuous conductive network is formed in the silicon nitride matrix by adding a conductive phase, so as to improve the conductivity of the silicon nitride-based complex-phase conductive ceramics, and the conductive phase has a stronger ability to absorb microwaves than the silicon nitride matrix.
  • Microwave sintering plays a promoting role, which is beneficial to reduce the microwave sintering temperature of silicon nitride-based composite phase conductive ceramics.
  • the source of the conductive phase is not particularly limited in the present invention, and commercially available products well known to those skilled in the art can be used.
  • the sintering aid includes rare earth oxides and metal oxides.
  • the addition of the sintering aid is beneficial to promote sintering and densification.
  • the mass content of the metal oxide in the green body is preferably 1-5%, more preferably 3-5%.
  • the metal oxide includes alumina or magnesia, preferably alumina.
  • the source of the alumina or magnesia is not particularly limited in the present invention, and commercially available products well known to those skilled in the art can be used.
  • the mass content of rare earth oxides in the green body is preferably 2-10%, more preferably 3-8%, and most preferably 4-6%.
  • the rare earth oxide preferably includes yttrium oxide, lanthanum oxide or cerium oxide.
  • the source of the rare earth oxide is not particularly limited in the present invention, and commercially available products well known to those skilled in the art may be used.
  • the raw material of the green body also preferably includes a microwave absorber.
  • the microwave absorber preferably includes silicon carbide or zirconia.
  • the mass content of the microwave absorbent in the green body is preferably 1-10%, more preferably 1-5%.
  • the silicon carbide or zirconia has high dielectric loss and strong microwave absorption capability, which can further enhance the microwave absorption capability of the silicon nitride-based complex phase conductive ceramics and reduce the sintering temperature.
  • the source of the microwave absorbent is not particularly limited in the present invention, and a commercially available product well known to those skilled in the art can be used.
  • the purities of the conductive phase, sintering aid and microwave absorber are preferably independently ⁇ 98%.
  • the average particle diameter D50 of the conductive phase, the sintering aid and the microwave absorber is preferably independently ⁇ 2.0 ⁇ m.
  • the average particle size of the conductive phase, the sintering aid and the microwave absorbent is preferably controlled within the above range, which is beneficial to promote sintering and densification and further reduce the sintering temperature.
  • the molding method preferably includes one or more of dry pressing, cold isostatic pressing, injection molding, coagulation and grouting.
  • the molding preferably includes: after mixing the raw materials uniformly, dry pressing is performed first, and then cold isostatic pressing is performed to obtain a green body.
  • the pressure of the dry pressing is preferably 10-25 MPa.
  • the size of the product obtained by the dry pressing is preferably 45 ⁇ 45 ⁇ 8 mm.
  • the pressure of the cold isostatic pressing is preferably 200 to 300 MPa.
  • the present invention sequentially performs high-temperature microwave sintering and low-temperature microwave sintering on the green body to obtain a silicon nitride-based complex-phase conductive ceramic.
  • the invention adopts the two-step microwave sintering method to prepare the silicon nitride-based complex-phase conductive ceramics, which can inhibit the grain boundary migration, and utilize the grain boundary diffusion to densify the green body; At the same time, it will not affect the densification.
  • the device for high-temperature microwave sintering and low-temperature microwave sintering is preferably a microwave sintering furnace.
  • the microwave sintering furnace is preferably as shown in FIG. 2
  • the microwave sintering furnace preferably includes an alumina fiber furnace, a temperature measuring device, a crucible and silicon carbide.
  • the alumina fiber furnace is used for heat insulation; the temperature measuring device is used for observing the sintering temperature; the crucible is used for placing the green body to be sintered, and the material of the crucible is preferably boron nitride;
  • the silicon carbide is used for auxiliary heating.
  • the temperature of the high-temperature microwave sintering is preferably 1500-1700°C.
  • the holding time of the high-temperature microwave sintering is preferably 0-30 min, more preferably 0-15 min.
  • the temperature of the low-temperature microwave sintering is preferably 1400-1600°C.
  • the holding time of the low-temperature microwave sintering is preferably 10-120 min, more preferably 20-80 min.
  • the temperature difference between the high-temperature microwave sintering and the low-temperature microwave sintering is preferably 50-150°C.
  • the heating rate of the high-temperature microwave sintering is preferably 2 ⁇ 30° C./min.
  • the cooling rate of cooling to the temperature of the low-temperature microwave sintering after high-temperature microwave sintering is preferably 30-80° C./min.
  • the green body it is preferable to first heat the green body to a relatively high temperature of 1500-1700°C and sinter the green body, and keep the temperature for 0-10min, and then rapidly cool down to a relatively low temperature of 1400-1600°C, and carry out the heat preservation for 10-120min, so as to inhibit the crystallinity. Boundary migration, and the use of grain boundary diffusion to densify the green body. Therefore, the use of this method can not only inhibit the growth of grains in the later stage of sintering, but also will not affect the densification. Performance has also been significantly improved.
  • the microwave frequency of the high-temperature microwave sintering and the low-temperature microwave sintering is preferably 2.45 GHz.
  • both the high-temperature microwave sintering and the low-temperature microwave sintering are preferably performed in a nitrogen atmosphere.
  • the flow rate of the nitrogen gas is preferably independently 0.5 to 5 L/min.
  • the present invention uses silicon nitride as a matrix, adds a conductive phase and a sintering aid at the same time, and adopts a two-step microwave sintering method to prepare a silicon nitride-based complex-phase conductive ceramic with fine and uniform crystal grains, high density, and high strength, hardness, etc. Mechanical properties have also been significantly improved.
  • Silicon nitride (the mass content of ⁇ -Si 3 N 4 ⁇ 95%, the average particle size D50 is 0.5 ⁇ m): 53%,
  • Titanium nitride (purity ⁇ 99%, average particle size D50 is 0.1 ⁇ m): 35%,
  • Yttrium oxide (purity ⁇ 99%, average particle size D50 is 0.2 ⁇ m): 6%,
  • Silicon carbide (purity ⁇ 98.5%, average particle size D50 is 0.5 ⁇ m): 3%.
  • dry pressing is performed first, the size of the obtained product is 45 ⁇ 45 ⁇ 8 mm, the pressure of dry pressing is 20 MPa, and then cold isostatic pressing is performed, and the pressure of cold isostatic pressing is 300 MPa to obtain green body.
  • the above-mentioned green body into the furnace cavity of the microwave sintering furnace, vacuumize until the vacuum degree in the furnace is less than 100Pa, and then introduce nitrogen to make the pressure in the furnace reach 0.1MPa.
  • the nitrogen flow rate is 1L/min, first heat up to 1600°C at a rate of 15°C/min, hold for 5 minutes, then cool down to 1550°C at a rate of 50°C/min, hold for 30mim, and then naturally cool to room temperature, The silicon nitride-based complex phase conductive ceramic is obtained.
  • Silicon nitride (the mass content of ⁇ -Si 3 N 4 ⁇ 95%, the average particle size D50 is 0.5 ⁇ m): 50%,
  • Titanium nitride (purity ⁇ 99%, average particle size D50 is 0.1 ⁇ m): 40%,
  • Yttrium oxide (purity ⁇ 99%, average particle size D50 is 0.2 ⁇ m): 5%
  • Silicon carbide (purity ⁇ 98.5%, average particle size D50 is 0.5 ⁇ m): 2%.
  • dry pressing is performed first, the size of the obtained product is 45 ⁇ 45 ⁇ 8 mm, the pressure of dry pressing is 20 MPa, and then cold isostatic pressing is performed, and the pressure of cold isostatic pressing is 300 MPa to obtain green body.
  • the above-mentioned green body into the furnace cavity of the microwave sintering furnace, vacuumize until the vacuum degree in the furnace is less than 100Pa, and then introduce nitrogen to make the pressure in the furnace reach 0.1MPa.
  • the nitrogen flow rate is 1L/min, first heat up to 1650°C at a rate of 15°C/min, hold for 0min, then cool down to 1550°C at a rate of 50°C/min, hold for 40mim, and then naturally cool to room temperature,
  • the silicon nitride-based complex phase conductive ceramic is obtained.
  • Silicon nitride (the mass content of ⁇ -Si 3 N 4 ⁇ 95%, the average particle size D50 is 0.5 ⁇ m): 48%,
  • Titanium nitride (purity ⁇ 99%, average particle size D50 is 0.1 ⁇ m): 45%,
  • Yttrium oxide (purity ⁇ 99%, average particle size D50 is 0.2 ⁇ m): 4%.
  • dry pressing is performed first, the size of the obtained product is 45 ⁇ 45 ⁇ 8 mm, the pressure of dry pressing is 20 MPa, and then cold isostatic pressing is performed, and the pressure of cold isostatic pressing is 300 MPa to obtain green body.
  • the above-mentioned green body into the furnace cavity of the microwave sintering furnace, vacuumize until the vacuum degree in the furnace is less than 100Pa, and then introduce nitrogen to make the pressure in the furnace reach 0.1MPa.
  • the nitrogen flow rate is 1L/min, first heat up to 1650°C at a rate of 15°C/min, hold for 5 minutes, then cool down to 1600°C at a rate of 50°C/min, hold for 30mim, and then naturally cool to room temperature, The silicon nitride-based complex phase conductive ceramic is obtained.
  • Silicon nitride (the mass content of ⁇ -Si 3 N 4 ⁇ 95%, the average particle size D50 is 0.5 ⁇ m): 50%,
  • Titanium nitride (purity ⁇ 99%, average particle size D50 is 0.1 ⁇ m): 40%,
  • Yttrium oxide (purity ⁇ 99%, average particle size D50 is 0.2 ⁇ m): 5%
  • Zirconia (purity ⁇ 99%, average particle size D50 is 0.5 ⁇ m): 2%.
  • dry pressing is performed first, the size of the obtained product is 45 ⁇ 45 ⁇ 8 mm, the pressure of dry pressing is 20 MPa, and then cold isostatic pressing is performed, and the pressure of cold isostatic pressing is 300 MPa to obtain green body.
  • the above-mentioned green body into the furnace cavity of the microwave sintering furnace, vacuumize until the vacuum degree in the furnace is less than 100Pa, and then introduce nitrogen to make the pressure in the furnace reach 0.1MPa.
  • the nitrogen flow rate is 1L/min, first heat up to 1600°C at a rate of 15°C/min, hold for 3 minutes, then cool down to 1550°C at a rate of 50°C/min, hold for 30mim, and then naturally cool to room temperature,
  • the silicon nitride-based complex phase conductive ceramic is obtained.
  • the obtained body is subjected to gas pressure sintering, the sintering temperature is 1750° C., the nitrogen pressure is 9.8 MPa, the temperature is kept for 3 hours, and then it is naturally cooled to room temperature to obtain a silicon nitride-based complex phase conductive ceramic.
  • the obtained body is subjected to gas pressure sintering, the sintering temperature is 1800° C., the nitrogen pressure is 9.8 MPa, the temperature is kept for 3 hours, and then it is naturally cooled to room temperature to obtain a silicon nitride-based complex phase conductive ceramic.
  • the obtained body is subjected to gas pressure sintering, the sintering temperature is 1850° C., the nitrogen pressure is 9.8 MPa, the temperature is kept for 2 hours, and then it is naturally cooled to room temperature to obtain a silicon nitride-based composite conductive ceramic.
  • the obtained body is subjected to gas pressure sintering, the sintering temperature is 1780° C., the nitrogen pressure is 9.8 MPa, the temperature is kept for 2 hours, and then it is naturally cooled to room temperature to obtain a silicon nitride-based complex phase conductive ceramic.
  • the flexural strength of the silicon nitride-based composite conductive ceramics prepared in Examples 1 to 4 and Comparative Examples 1 to 4 was tested by the method for testing flexural strength in the standard GB/T 6569-2006, wherein the size of the test sample was 40 ⁇ 3 ⁇ 4mm, the three-point bending strength is tested, and the span is 30mm.
  • the test results are shown in Table 1.
  • microstructures of the silicon nitride-based composite conductive ceramics prepared in Examples 1-4 and Comparative Examples 1-4 were observed by scanning electron microscope, as shown in Figure 1, and the grain size was determined on the SEM pictures taken randomly. Measurement, the number of crystal grains counted for each sample is not less than 500, and the test results are shown in Table 1.
  • the preparation method provided by the present invention improves the mechanical properties such as the strength and hardness of the ceramic while realizing the densification of the silicon nitride-based composite conductive ceramic.
  • the relative density of the silicon nitride-based multiphase conductive ceramic prepared by the invention is greater than 99%, the Vickers hardness is greater than 15GPa, the fracture toughness is greater than 6MPa ⁇ m 1/2 , the flexural strength is greater than 900MPa, and the resistivity is less than 1 ⁇ cm.

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Abstract

本发明提供了一种氮化硅基复相导电陶瓷的制备方法，本发明以氮化硅为基体，同时添加导电相以及烧结助剂，采用两步微波烧结法，制备的氮化硅基复相导电陶瓷晶粒细小且均匀、致密度高，且强度、硬度等力学性能也得到了显著提升。本发明采用的两步微波烧结法，可抑制晶界迁移，并利用晶界扩散使坯体达到致密化；因此，该方法既可以抑制烧结后期晶粒的生长，同时又不会影响致密化的进行。实施例的结果显示，本发明提供的氮化硅基复相导电陶瓷的相对密度大于99％，维氏硬度大于15GPa，断裂韧性大于6MPa·m 1/2，抗弯强度大于900MPa，电阻率小于1Ω·cm。

Description

一种氮化硅基复相导电陶瓷的制备方法
本申请要求于2021年02月02日提交中国专利局、申请号为202110140908.2、发明名称为“一种氮化硅基复相导电陶瓷的制备方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及导电陶瓷技术领域，尤其涉及一种氮化硅基复相导电陶瓷的制备方法。
背景技术
氮化硅陶瓷综合力学性能优异，尤其是兼具高强度、高硬度、高韧性和耐磨性能良好的优点，而且具有较高的化学稳定性和抗热震性，是一种理想的工程陶瓷材料，广泛用于机械、化工、航空航天及国防军工等领域。但是，由于氮化硅陶瓷具有电绝缘性，因而只能采用传统的金刚石工具进行机械加工，加工效率低、成本高，且无法加工成形状复杂的部件，严重限制了氮化硅陶瓷的应用。
通过在氮化硅陶瓷中引入钛基化合物(TiN、TiC、TiCN、TiB 2)、锆基化合物(ZrN、ZrC、ZrB 2)或MoSi 2等导电相，可以提高氮化硅陶瓷的导电性，进而可以采用电火花加工，提高了加工效率，解决了上述无法加工成形状复杂的部件的问题。但是，导电相的加入会阻碍氮化硅的烧结致密化，使得制备复相导电陶瓷时，需要采用热压烧结或高温(≥1800℃)气压烧结才能实现致密化，而采用上述烧结方法又会导致氮化硅陶瓷硬度、强度等力学性能的下降。
因此，为了实现形状复杂的氮化硅陶瓷部件的快速加工，亟需提供一种能够实现氮化硅基复相陶瓷致密化的同时保证氮化硅陶瓷力学性能的方法。
发明内容
本发明的目的在于提供一种氮化硅基复相导电陶瓷的制备方法，本发明提供的制备方法可抑制晶界迁移，并利用晶界扩散使坯体达到致密化， 因此，提升了氮化硅基复相导电陶瓷的强度、硬度等力学性能。
为了实现上述发明目的，本发明提供了以下技术方案：
本发明提供了一种氮化硅基复相导电陶瓷的制备方法，包括以下步骤：
(1)将氮化硅、导电相以及烧结助剂混合后通过成型，得到坯体；所述烧结助剂包括稀土氧化物和金属氧化物，所述金属氧化物包括氧化铝或氧化镁；
(2)将所述步骤(1)得到的坯体依次进行高温微波烧结和低温微波烧结，得到氮化硅基复相导电陶瓷。
优选地，所述步骤(1)的坯体中氮化硅的质量含量为40～60％，导电相的质量含量为30～50％，金属氧化物的质量含量为1～5％，稀土氧化物的质量含量为2～10％。
优选地，所述导电相包括TiN、TiC、TiCN、TiB 2、ZrN、ZrC、ZrB 2或MoSi 2。
优选地，所述稀土氧化物包括氧化钇、氧化镧或氧化铈。
优选地，所述氮化硅中β-Si 3N 4的质量含量为≥85％。
优选地，所述氮化硅的平均粒径D50≤1.0μm。
优选地，所述步骤(1)中坯体的原料还包括微波吸收剂。
优选地，所述微波吸收剂包括碳化硅或氧化锆。
优选地，所述步骤(1)中成型的方式包括干压、冷等静压、注塑、注凝和注浆中的一种或几种。
优选地，所述步骤(2)中高温微波烧结的温度为1500～1700℃，所述高温微波烧结的保温时间为0～30min。
优选地，所述低温微波烧结的温度为1400～1600℃，所述低温微波烧结的保温时间为10～120mim。
优选地，所述高温微波烧结和低温微波烧结的温度差为50～150℃。
优选地，所述步骤(2)中高温微波烧结的升温速率为2～30℃/min。
优选地，高温微波烧结后降温至所述低温微波烧结的温度的降温速率为30～80℃/min。
优选地，所述步骤(2)中的高温微波烧结和低温微波烧结均在氮气 气氛中进行，所述氮气的流量独立地为0.5～5L/min。
本发明提供了一种氮化硅基复相导电陶瓷的制备方法，包括以下步骤：将氮化硅、导电相以及烧结助剂混合后通过成型，得到坯体；将所述坯体依次进行高温微波烧结和低温微波烧结，得到氮化硅基复相导电陶瓷；所述烧结助剂包括稀土氧化物和金属氧化物，所述金属氧化物包括氧化铝或氧化镁。本发明以氮化硅为基体，同时添加导电相以及烧结助剂，采用两步微波烧结法，制备的氮化硅基复相导电陶瓷晶粒细小且均匀、致密度高，且强度、硬度等力学性能也得到了显著提升。本发明通过添加导电相，在氮化硅基体中形成连续的导电网络，提高氮化硅基陶瓷的导电性，并且导电相具有比氮化硅基体更强的吸收微波能力，能对微波烧结起到促进作用，有利于降低氮化硅基复相导电陶瓷的微波烧结温度；通过添加烧结助剂，有利于促进烧结致密化。本发明采用的两步微波烧结法，可抑制晶界迁移，并利用晶界扩散使坯体达到致密化；因此，该方法既可以抑制烧结后期晶粒的生长，同时又不会影响致密化的进行。实施例的结果显示，本发明提供的氮化硅基复相导电陶瓷的相对密度大于99％，维氏硬度大于15GPa，断裂韧性大于6MPa·m 1/2，抗弯强度大于900MPa，电阻率小于1Ω·cm。
附图说明
图1为本发明实施例1～4和对比例1～4制备的氮化硅基复相导电陶瓷的显微结构示意图；
图2为本发明中采用的微波烧结炉的示意图；
其中，1-氧化铝纤维炉膛，2-测温装置，3-坩埚，4-碳化硅，5-待烧结坯体。
具体实施方式
本发明提供了一种氮化硅基复相导电陶瓷的制备方法，包括以下步骤：
(1)将氮化硅、导电相以及烧结助剂混合后通过成型，得到坯体；所述烧结助剂包括稀土氧化物和金属氧化物，所述金属氧化物包括氧化铝 或氧化镁；
(2)将所述步骤(1)得到的坯体依次进行高温微波烧结和低温微波烧结，得到氮化硅基复相导电陶瓷。
本发明将氮化硅、导电相以及烧结助剂混合后通过成型，得到坯体。
在本发明中，所述坯体中氮化硅的质量含量优选为40～60％，更优选为45～55％。在本发明中，所述氮化硅中β-Si 3N 4的质量含量优选为≥85％，更优选为≥95％。本发明优选将所述氮化硅中β-Si 3N 4的质量含量控制在上述范围，有利于使烧结后的氮化硅形成均匀细小的等轴状晶粒。在本发明中，所述氮化硅的平均粒径D50优选为≤1.0μm。本发明优选将所述氮化硅的平均粒径控制在上述范围，能够防止氮化硅的平均粒径过大时阻碍烧结致密化，使烧结温度升高。本发明对所述氮化硅的来源没有特殊的限定，采用本领域技术人员熟知的市售产品即可。
在本发明中，所述坯体中导电相的质量含量优选为30～50％，更优选为30～45％。在本发明中，所述导电相优选包括TiN、TiC、TiCN、TiB 2、ZrN、ZrC、ZrB 2或MoSi 2，更优选为TiN、TiC、ZrC或MoSi 2。本发明通过添加导电相，在氮化硅基体中形成连续的导电网络，提高氮化硅基复相导电陶瓷的导电性，并且导电相具有比氮化硅基体更强的吸收微波能力，能对微波烧结起到促进作用，有利于降低氮化硅基复相导电陶瓷的微波烧结温度。本发明对所述导电相的来源没有特殊的限定，采用本领域技术人员熟知的市售产品即可。
在本发明中，所述烧结助剂包括稀土氧化物和金属氧化物。在本发明中，所述烧结助剂的添加，有利于促进烧结致密化。
在本发明中，所述坯体中金属氧化物的质量含量优选为1～5％，更优选为3～5％。在本发明中，所述金属氧化物包括氧化铝或氧化镁，优选为氧化铝。本发明对所述氧化铝或氧化镁的来源没有特殊的限定，采用本领域技术人员熟知的市售产品即可。
在本发明中，所述坯体中稀土氧化物的质量含量优选为2～10％，更优选为3～8％，最优选为4～6％。在本发明中，所述稀土氧化物优选包括氧化钇、氧化镧或氧化铈。本发明对所述稀土氧化物的来源没有特殊的限定，采用本领域技术人员熟知的市售产品即可。
在本发明中，所述坯体的原料还优选包括微波吸收剂。在本发明中，所述微波吸收剂优选包括碳化硅或氧化锆。在本发明中，所述坯体中微波吸收剂的质量含量优选为1～10％，更优选为1～5％。在本发明中，所述碳化硅或氧化锆的介质损耗高，具有极强的吸收微波能力，可以进一步增强氮化硅基复相导电陶瓷对微波的吸收能力，降低烧结温度。本发明对所述微波吸收剂的来源没有特殊的限定，采用本领域技术人员熟知的市售产品即可。
在本发明中，所述导电相、烧结助剂和微波吸收剂的纯度优选独立地为≥98％。
在本发明中，所述导电相、烧结助剂和微波吸收剂的平均粒径D50优选独立地为≤2.0μm。本发明优选将所述导电相、烧结助剂和微波吸收剂的平均粒径控制在上述范围，有利于促进烧结致密化，进一步降低烧结温度。
在本发明中，所述成型的方式优选包括干压、冷等静压、注塑、注凝和注浆中的一种或几种。在本发明中，所述成型优选包括：将原料混合均匀后先进行干压成型，再进行冷等静压处理，得到坯体。在本发明中，所述干压成型的压力优选为10～25MPa。在本发明中，所述干压成型得到的产物的尺寸优选为45×45×8mm。在本发明中，所述冷等静压处理的压力优选为200～300MPa。
得到坯体后，本发明将所述坯体依次进行高温微波烧结和低温微波烧结，得到氮化硅基复相导电陶瓷。本发明采用两步微波烧结法制备氮化硅基复相导电陶瓷，可抑制晶界迁移，并利用晶界扩散使坯体达到致密化；因此，该方法既可以抑制烧结后期晶粒的生长，同时又不会影响致密化的进行。
在本发明中，所述高温微波烧结和低温微波烧结的装置优选为微波烧结炉。在本发明中，所述微波烧结炉优选如图2所示，所述微波烧结炉优选包括氧化铝纤维炉膛、测温装置、坩埚以及碳化硅。在本发明中，所述氧化铝纤维炉膛用于隔热保温；所述测温装置用于观测烧结温度；所述坩埚用于放置待烧结坯体，所述坩埚的材质优选为氮化硼；所述碳化硅用于辅助加热。
在本发明中，所述高温微波烧结的温度优选为1500～1700℃。在本发明中，所述高温微波烧结的保温时间优选为0～30min，更优选为0～15min。
在本发明中，所述低温微波烧结的温度优选为1400～1600℃。在本发明中，所述低温微波烧结的保温时间优选为10～120mim，更优选为20～80min。
在本发明中，所述高温微波烧结和低温微波烧结的温度差优选为50～150℃。
在本发明中，所述高温微波烧结的升温速率优选为2～30℃/min。在本发明中，高温微波烧结后降温至所述低温微波烧结的温度的降温速率优选为30～80℃/min。
本发明优选先升温到一个较高的温度1500～1700℃烧结坯体，并保温0～10min，再快速降温到相对较低的温度1400～1600℃，并进行10～120min的保温，从而抑制晶界迁移，并利用晶界扩散使坯体达到致密化。因此，采用该方法既可以抑制烧结后期晶粒的生长，同时又不会影响致密化的进行，制备的氮化硅基复相导电陶瓷晶粒细小且均匀，致密度高，强度、硬度等力学性能也得到了显著提升。
在本发明中，所述高温微波烧结和低温微波烧结的微波频率优选为2.45GHz。
在本发明中，所述高温微波烧结和低温微波烧结优选均在氮气气氛中进行。在本发明中，所述氮气的流量优选独立地为0.5～5L/min。
本发明以氮化硅为基体，同时添加导电相以及烧结助剂，采用两步微波烧结法，制备的氮化硅基复相导电陶瓷晶粒细小且均匀、致密度高，且强度、硬度等力学性能也得到了显著提升。
下面将结合本发明中的实施例，对本发明中的技术方案进行清楚、完整地描述。显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
实施例1
原料：
氮化硅(β-Si 3N 4的质量含量≥95％，平均粒径D50为0.5μm)：53％，
氮化钛(纯度≥99％，平均粒径D50为0.1μm)：35％，
氧化铝(纯度≥99％，平均粒径D50为0.5μm)：3％，
氧化钇(纯度≥99％，平均粒径D50为0.2μm)：6％，
碳化硅(纯度≥98.5％，平均粒径D50为0.5μm)：3％。
将上述原料混合均匀后先进行干压成型，所得产物的尺寸为45×45×8mm，干压成型的压力为20MPa，再进行冷等静压处理，冷等静压处理的压力为300MPa，得到坯体。将上述坯体放入微波烧结炉的炉腔中，抽真空至炉内真空度小于100Pa，然后通入氮气使炉内压力达到0.1MPa，反复两次进行洗炉后，在0.1MPa的流动氮气气氛中开始升温，氮气流量为1L/min，先以15℃/min的速率升温到1600℃，保温5min，然后以50℃/min的速率降温到1550℃，保温30mim，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
实施例2
原料：
氮化硅(β-Si 3N 4的质量含量≥95％，平均粒径D50为0.5μm)：50％，
氮化钛(纯度≥99％，平均粒径D50为0.1μm)：40％，
氧化铝(纯度≥99％，平均粒径D50为0.5μm)：3％，
氧化钇(纯度≥99％，平均粒径D50为0.2μm)：5％，
碳化硅(纯度≥98.5％，平均粒径D50为0.5μm)：2％。
将上述原料混合均匀后先进行干压成型，所得产物的尺寸为45×45×8mm，干压成型的压力为20MPa，再进行冷等静压处理，冷等静压处理的压力为300MPa，得到坯体。将上述坯体放入微波烧结炉的炉腔中，抽真空至炉内真空度小于100Pa，然后通入氮气使炉内压力达到0.1MPa，反复两次进行洗炉后，在0.1MPa的流动氮气气氛中开始升温，氮气流量为1L/min，先以15℃/min的速率升温到1650℃，保温0min，然后以50℃/min的速率降温到1550℃，保温40mim，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
实施例3
原料：
氮化硅(β-Si 3N 4的质量含量≥95％，平均粒径D50为0.5μm)：48％，
氮化钛(纯度≥99％，平均粒径D50为0.1μm)：45％，
氧化铝(纯度≥99％，平均粒径D50为0.5μm)：3％，
氧化钇(纯度≥99％，平均粒径D50为0.2μm)：4％。
将上述原料混合均匀后先进行干压成型，所得产物的尺寸为45×45×8mm，干压成型的压力为20MPa，再进行冷等静压处理，冷等静压处理的压力为300MPa，得到坯体。将上述坯体放入微波烧结炉的炉腔中，抽真空至炉内真空度小于100Pa，然后通入氮气使炉内压力达到0.1MPa，反复两次进行洗炉后，在0.1MPa的流动氮气气氛中开始升温，氮气流量为1L/min，先以15℃/min的速率升温到1650℃，保温5min，然后以50℃/min的速率降温到1600℃，保温30mim，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
实施例4
原料：
氮化硅(β-Si 3N 4的质量含量≥95％，平均粒径D50为0.5μm)：50％，
氮化钛(纯度≥99％，平均粒径D50为0.1μm)：40％，
氧化镁(纯度≥98％，平均粒径D50为0.2μm)：3％，
氧化钇(纯度≥99％，平均粒径D50为0.2μm)：5％，
氧化锆(纯度≥99％，平均粒径D50为0.5μm)：2％。
将上述原料混合均匀后先进行干压成型，所得产物的尺寸为45×45×8mm，干压成型的压力为20MPa，再进行冷等静压处理，冷等静压处理的压力为300MPa，得到坯体。将上述坯体放入微波烧结炉的炉腔中，抽真空至炉内真空度小于100Pa，然后通入氮气使炉内压力达到0.1MPa，反复两次进行洗炉后，在0.1MPa的流动氮气气氛中开始升温，氮气流量为1L/min，先以15℃/min的速率升温到1600℃，保温3min，然后以50℃/min的速率降温到1550℃，保温30mim，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
对比例1
采用和实施例1相同的原料组成和成型工艺，得到坯体。
将得到的坯体进行气压烧结，烧结温度为1750℃，氮气压力为9.8MPa，保温3h，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
对比例2
采用和实施例2相同的原料组成和成型工艺，得到坯体。
将得到的坯体进行气压烧结，烧结温度为1800℃，氮气压力为9.8MPa，保温3h，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
对比例3
采用和实施例3相同的原料组成和成型工艺，得到坯体。
将得到的坯体进行气压烧结，烧结温度为1850℃，氮气压力为9.8MPa，保温2h，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
对比例4
采用和实施例4相同的原料组成和成型工艺，得到坯体。
将得到的坯体进行气压烧结，烧结温度为1780℃，氮气压力为9.8MPa，保温2h，之后自然冷却至室温，得到氮化硅基复相导电陶瓷。
性能测试
采用阿基米德排水法测试实施例1～4和对比例1～4制备的氮化硅基复相导电陶瓷的密度，并计算相对密度，结果见表1。
采用压痕法测试实施例1～4和对比例1～4制备的氮化硅基复相导电陶瓷的维氏硬度和断裂韧性，施加载荷为196N，测试结果见表1。
采用标准GB/T 6569-2006中测试抗弯强度的方法测试实施例1～4和对比例1～4制备的氮化硅基复相导电陶瓷的抗弯强度，其中，测试样品的规格为40×3×4mm，测试三点抗弯强度，跨距为30mm，测试结果见表1。
采用扫描电子显微镜观察实施例1～4和对比例1～4制备的氮化硅基复相导电陶瓷的显微结构，如图1所示，并在随机拍摄的SEM照片上完成晶粒尺寸的测量，每个样品统计的晶粒数目不少于500个，测试结果见表1。
表1 实施例1～4以及对比例1～4制备的氮化硅基复相导电陶瓷的性能
Figure PCTCN2022072864-appb-000001
Figure PCTCN2022072864-appb-000002
由以上实施例可以看出，本发明提供的制备方法在实现氮化硅基复相导电陶瓷致密化的同时提升了陶瓷的强度、硬度等力学性能。并且，本发明制备的氮化硅基复相导电陶瓷的相对密度大于99％，维氏硬度大于15GPa，断裂韧性大于6MPa·m 1/2，抗弯强度大于900MPa，电阻率小于1Ω·cm。
以上实施例的说明只是用于帮助理解本发明的方法及其核心思想。应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以对本发明进行若干改进和修饰，这些改进和修饰也落入本发明权利要求的保护范围内。对这些实施例的多种修改对本领域的专业技术人员来说是显而易见的，本文中所定义的一般原理可以在不脱离本发明的精神或范围的情况下在其它实施例中实现。因此，本发明将不会被限制于本文所示的这些实施例，而是要符合与本文所公开的原理和新颖特点相一致的最宽的范围。

Claims (15)

  1. 一种氮化硅基复相导电陶瓷的制备方法，包括以下步骤：
    (1)将氮化硅、导电相以及烧结助剂混合后通过成型，得到坯体；所述烧结助剂包括稀土氧化物和金属氧化物，所述金属氧化物包括氧化铝或氧化镁；
    (2)将所述步骤(1)得到的坯体依次进行高温微波烧结和低温微波烧结，得到氮化硅基复相导电陶瓷。
  2. 根据权利要求1所述的制备方法，其特征在于，所述步骤(1)的坯体中氮化硅的质量含量为40～60％，导电相的质量含量为30～50％，金属氧化物的质量含量为1～5％，稀土氧化物的质量含量为2～10％。
  3. 根据权利要求1或2所述的制备方法，其特征在于，所述导电相包括TiN、TiC、TiCN、TiB 2、ZrN、ZrC、ZrB 2或MoSi 2。
  4. 根据权利要求1或2所述的制备方法，其特征在于，所述稀土氧化物包括氧化钇、氧化镧或氧化铈。
  5. 根据权利要求1或2所述的制备方法，其特征在于，所述氮化硅中β-Si 3N 4的质量含量为≥85％。
  6. 根据权利要求1或2所述的制备方法，其特征在于，所述氮化硅的平均粒径D50≤1.0μm。
  7. 根据权利要求1所述的制备方法，其特征在于，所述步骤(1)中坯体的原料还包括微波吸收剂。
  8. 根据权利要求7所述的制备方法，其特征在于，所述微波吸收剂包括碳化硅或氧化锆。
  9. 根据权利要求1所述的制备方法，其特征在于，所述步骤(1)中成型的方式包括干压、冷等静压、注塑、注凝和注浆中的一种或几种。
  10. 根据权利要求1所述的制备方法，其特征在于，所述步骤(2)中高温微波烧结的温度为1500～1700℃，所述高温微波烧结的保温时间为0～30min。
  11. 根据权利要求1所述的制备方法，其特征在于，所述步骤(2)中低温微波烧结的温度为1400～1600℃，所述低温微波烧结的保温时间为 10～120mim。
  12. 根据权利要求1所述的制备方法，其特征在于，所述步骤(2)中高温微波烧结和低温微波烧结的温度差为50～150℃。
  13. 根据权利要求1或10所述的制备方法，其特征在于，所述步骤(2)中高温微波烧结的升温速率为2～30℃/min。
  14. 根据权利要求1或11所述的制备方法，其特征在于，所述步骤(2)中高温微波烧结后降温至所述低温微波烧结的温度的降温速率为30～80℃/min。
  15. 根据权利要求1所述的制备方法，其特征在于，所述步骤(2)中的高温微波烧结和低温微波烧结均在氮气气氛中进行，所述氮气的流量独立地为0.5～5L/min。
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115448729A (zh) * 2022-10-12 2022-12-09 郑州大学 一种BN-ZrO2-SiC复相陶瓷的微波烧结方法
CN115504795A (zh) * 2022-09-22 2022-12-23 衡阳凯新特种材料科技有限公司 一种高强度氮化硅透波陶瓷及其制备方法
CN115594507A (zh) * 2022-10-12 2023-01-13 郑州格瑞特高温材料有限公司（Cn） 一种低密度微孔氮化硅结合碳化硅材料及其制备方法
CN115716751A (zh) * 2022-11-25 2023-02-28 北京钢研新冶工程技术中心有限公司 一种改性碳化硅陶瓷及其制备方法
CN116730724A (zh) * 2023-05-05 2023-09-12 衡阳凯新特种材料科技有限公司 一种用于陶瓷探针的碳化硅复合陶瓷材料及其制备方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112851365B (zh) * 2021-02-02 2022-03-29 中材高新氮化物陶瓷有限公司 一种氮化硅基复相导电陶瓷的制备方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104817327A (zh) * 2015-03-27 2015-08-05 冷水江市明玉陶瓷工具有限责任公司 一种氮化硅复合陶瓷模具材料及其制备方法与应用
CN106810264A (zh) * 2015-11-27 2017-06-09 衡阳凯新特种材料科技有限公司 一种氮化硅陶瓷的制备方法
CN111635236A (zh) * 2020-05-26 2020-09-08 南京理工大学 一种微波烧结塞隆陶瓷材料的方法
CN112851365A (zh) * 2021-02-02 2021-05-28 中材高新氮化物陶瓷有限公司 一种氮化硅基复相导电陶瓷的制备方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63185864A (ja) * 1986-09-05 1988-08-01 株式会社日立製作所 複合セラミツクスおよびその製法
DE3840173A1 (de) * 1988-11-29 1990-05-31 Hoechst Ag Siliciumnitridkeramik mit devitrifizierter integranularer glasphase und verfahren zu ihrer herstellung
US5173458A (en) * 1990-12-28 1992-12-22 Sumitomo Electric Industries, Ltd. Silicon nitride sintered body and process for producing the same
US5908796A (en) * 1998-05-01 1999-06-01 Saint-Gobain Industrial Ceramics, Inc. Dense silicon nitride ceramic having fine grained titanium carbide
CN108675797B (zh) * 2018-06-27 2021-05-04 南京理工大学 氮化硅基复合陶瓷材料及其微波烧结制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104817327A (zh) * 2015-03-27 2015-08-05 冷水江市明玉陶瓷工具有限责任公司 一种氮化硅复合陶瓷模具材料及其制备方法与应用
CN106810264A (zh) * 2015-11-27 2017-06-09 衡阳凯新特种材料科技有限公司 一种氮化硅陶瓷的制备方法
CN111635236A (zh) * 2020-05-26 2020-09-08 南京理工大学 一种微波烧结塞隆陶瓷材料的方法
CN112851365A (zh) * 2021-02-02 2021-05-28 中材高新氮化物陶瓷有限公司 一种氮化硅基复相导电陶瓷的制备方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GUO WEI-MING, GU SHANG-XIAN;SU GUO-KANG;LI JING-XI;LIN HUA-TAI;WU SHANG-HUA: "Research Progress of Electroconductive Si3N4-Based Ceramics)", ADVANCED CERAMICS, vol. 37, no. 2, 15 April 2016 (2016-04-15), pages 94 - 106, XP055957326, ISSN: 1005-1198 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115504795A (zh) * 2022-09-22 2022-12-23 衡阳凯新特种材料科技有限公司 一种高强度氮化硅透波陶瓷及其制备方法
CN115448729A (zh) * 2022-10-12 2022-12-09 郑州大学 一种BN-ZrO2-SiC复相陶瓷的微波烧结方法
CN115594507A (zh) * 2022-10-12 2023-01-13 郑州格瑞特高温材料有限公司（Cn） 一种低密度微孔氮化硅结合碳化硅材料及其制备方法
CN115594507B (zh) * 2022-10-12 2023-05-30 郑州格瑞特高温材料有限公司 一种低密度微孔氮化硅结合碳化硅材料及其制备方法
CN115716751A (zh) * 2022-11-25 2023-02-28 北京钢研新冶工程技术中心有限公司 一种改性碳化硅陶瓷及其制备方法
CN116730724A (zh) * 2023-05-05 2023-09-12 衡阳凯新特种材料科技有限公司 一种用于陶瓷探针的碳化硅复合陶瓷材料及其制备方法

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