NASA的Glenn Research Center的创新者开发了两个耐用的环境屏障涂层(EBCS),适用于陶瓷基质复合材料(CMC)组分。CMC是轻质复合材料,用于降低先进的燃气轮机和其他高温,高应力环境(高达1482°C)的燃料消耗。格伦的突破EBC是唯一能够承受这种温度的涂层,保护CMC免受极端环境中的磨损和腐蚀,氧化和水汽衰退的增加。此外,这些EBC可以通过比常规涂覆方法(例如等离子体喷涂)更简单和更低的方法制造。

Glenn's EBCs enable lightweight CMC engine vanes that are oxidation-resistant, reducing maintenance needs and extending life.

Glenn's EBCs add reliability and life-span to CMCs’ advantages of lighter weight, higher temperature capability, and greater oxidation resistance. This innovation is poised to facilitate the upcoming CMC revolution, from hot components in next-generation, fuel-efficient jet engines, to furnaces and nuclear reactors.

由于其重量较轻,更高的温度能力和耐氧化,CMC是多种应用的游戏更换器。据估计,依赖于CMCS的飞机设计可以将燃料消耗降低10%。EBCS用于保护来自电气蒸气和其他极端环境的水蒸气和其他腐蚀性气体的CMC。EBCS的最新技术具有硅粘合涂层,其不可容易,其熔点为1482℃。相比之下,Glenn的EBC已经证明了在1482°C的蒸汽氧化寿命至少为500小时,使其成为下一代CMC的理想耐用涂料。

These EBCs are slurries, with either a mullite-based bond coat or a rare earth disilicate-based bond coat comprising at least three and two layers, respectively. Mullite is often used as a refractory material for furnaces, reactors, etc. because of its high melting point (1840 °C). Rare earth disilicates also have high melting points (~1800 °C). These bond coats can be fabricated by preparing a mixture of a coating material, a primary sintering aid, at least one secondary sintering aid, and a solvent. The mixture is then processed (e.g., in a milling media) to form a slurry that can be deposited to a CMC substrate.

The sintering aids have two primary functions: 1) densifying deposited slurry by generating liquid phases via reactions with the coating material and other sintering aids, so that the liquid fills gaps between particles of coated material; and 2) enhancing bonding and performance of the coating by generating reaction products that enhance those qualities. One great advantage of this EBC is that it can be fabricated via various low-cost methods including dipping, spinning, spin-dipping, painting, and spraying, in addition to plasma-spraying.

Contact the Glenn Technology Transfer Office atThis email address is being protected from spambots. You need JavaScript enabled to view it.or 216-433-3484. Follow this linkherefor more information.


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This article first appeared in the January, 2020 issue of金宝搏官网Magazine.

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