The excellent thermal properties and corrosion resistance make porous ceramic structures attractive for a wide range of technical applications, such as solar receivers, catalytic converters, reformers, heat exchangers, porous-media burners (PMBs), thermal protection, and transpiration cooling materials in hypersonic applications (see Figure 1 for representative examples). Various high-performance ceramic materials are utilized in these technical applications, including alumina (Al2O3), yttria-stabilized zirconia alumina (YZA), and silicon carbide (SiC). Al2O3 enables the highest maximum use temperature, but has intermediate resistance to thermal shock, whereas SiC has superior thermal shock resistance and thermal conductivity, but lower usage temperature. Thus, different properties metrics determine the application of the material for high-temperature applications. In addition to the material composition, the local porous structure directly affects global properties such as total heat transfer across a porous material or heat exchange between the working fluid and the solid structure. Therefore, the ability for tailoring the structure is critical for numerous applications. Traditional ceramic fabrication methods involving pressing or casting result in dense, low-porosity materials. Therefore, manufacturing highly porous structures with controlled porosity requires the use of special manufacturing techniques. Such techniques primarily rely on the replication of a high-porosity polymer or carbon structure either by coating with a ceramic slurry or by vapor deposition. Alternatively, highly porous ceramic materials can be produced by foaming methods, which incorporate a gas into a suspension that subsequently sets to maintain the structure of the bubbles. These techniques are not directly amenable to the tailoring of the local porous structure, thus enabling structural tailoring for optimizing the system performance necessitates the use of advanced manufacturing techniques, such as additive manufacturing (AM). AM allows for the fabrication of highly complex and tailored structures from computer-aided design (CAD) model data. However, the highmelting temperatures of ceramics have made them specially challenging for AM, with only a few technologies capable of converting a digital representation to a physical ceramic structure. An additional challenge to creating complex porous ceramic structures is resolving the sub-millimeter pore and strut features, which are relevant for practical applications. Leveraging the technologies available for polymer AM, previous studies have applied customized template-polymer structures in the traditional replication methodology to enable tailored ceramic structures. However, the replication method relies on the burnout of the underlying template Dr. S. Sobhani Sibley School of Mechanical and Aerospace Engineering Cornell University Ithaca, NY 14853, USA E-mail: sobhani@cornell.edu Dr. S. Sobhani, P. Muhunthan, E. Boigne, Prof. M. Ihme Department of Mechanical Engineering Stanford University Stanford, CA 94305, USA S. Allan Lithoz America LLC Troy, NY 12180, USA

中文翻译：

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用于高温应用的定制大孔陶瓷结构的增材制造

优异的热性能和耐腐蚀性使多孔陶瓷结构对广泛的技术应用具有吸引力，例如太阳能接收器、催化转化器、重整器、热交换器、多孔介质燃烧器 (PMB)、热保护和高超音速蒸腾冷却材料应用程序（有关代表性示例，请参见图 1）。在这些技术应用中使用了各种高性能陶瓷材料，包括氧化铝 (Al2O3)、氧化钇稳定的氧化锆氧化铝 (YZA) 和碳化硅 (SiC)。Al2O3 能够实现最高的最高使用温度，但具有中等的耐热冲击性，而 SiC 具有优异的耐热冲击性和导热性，但使用温度较低。因此，不同的性能指标决定了材料在高温应用中的应用。除了材料成分外，局部多孔结构还直接影响全局特性，例如多孔材料的总传热或工作流体与固体结构之间的热交换。因此，定制结构的能力对于众多应用至关重要。涉及压制或铸造的传统陶瓷制造方法会产生致密、低孔隙率的材料。因此，制造具有受控孔隙率的高度多孔结构需要使用特殊的制造技术。此类技术主要依赖于通过陶瓷浆料涂覆或气相沉积来复制高孔隙率聚合物或碳结构。或者，高度多孔的陶瓷材料可以通过发泡方法生产，该方法将气体加入悬浮液中，悬浮液随后凝固以保持气泡的结构。这些技术不能直接适用于局部多孔结构的剪裁，因此为了优化系统性能而进行结构剪裁需要使用先进的制造技术，例如增材制造 (AM)。AM 允许根据计算机辅助设计 (CAD) 模型数据制造高度复杂和量身定制的结构。然而，陶瓷的高熔点使它们对 AM 具有特别的挑战性，只有少数技术能够将数字表示转换为物理陶瓷结构。创建复杂多孔陶瓷结构的另一个挑战是解决与实际应用相关的亚毫米孔隙和支柱特征。利用可用于聚合物 AM 的技术，先前的研究已经在传统复制方法中应用定制的模板聚合物结构，以实现定制的陶瓷结构。然而，复制方法依赖于底层模板的倦怠。 S. Sobhani Sibley 博士康奈尔大学伊萨卡大学机械与航空航天工程学院，NY 14853，美国电子邮件：sobhani@cornell.edu Dr. S. Sobhani, P. Muhunthan, E. Boigne, Prof. M. Ihme 斯坦福大学机械工程系斯坦福大学, CA 94305, USA S. Allan Lithoz America LLC Troy, NY 12180, USA 利用可用于聚合物 AM 的技术，先前的研究已经在传统复制方法中应用定制的模板聚合物结构，以实现定制的陶瓷结构。然而，复制方法依赖于底层模板的倦怠。 S. Sobhani Sibley 博士康奈尔大学伊萨卡大学机械与航空航天工程学院，NY 14853，美国电子邮件：sobhani@cornell.edu Dr. S. Sobhani, P. Muhunthan, E. Boigne, Prof. M. Ihme 斯坦福大学机械工程系斯坦福大学, CA 94305, USA S. Allan Lithoz America LLC Troy, NY 12180, USA 利用可用于聚合物 AM 的技术，先前的研究已经在传统复制方法中应用定制的模板聚合物结构，以实现定制的陶瓷结构。然而，复制方法依赖于底层模板的倦怠。 S. Sobhani Sibley 博士康奈尔大学伊萨卡大学机械与航空航天工程学院，NY 14853，美国电子邮件：sobhani@cornell.edu Dr. S. Sobhani, P. Muhunthan, E. Boigne, Prof. M. Ihme 斯坦福大学机械工程系斯坦福大学, CA 94305, USA S. Allan Lithoz America LLC Troy, NY 12180, USA