GOALI: Fundamental Investigation of the Synthesis, Characterization, and Performance of a NiAl Diffusion Coating Doped with a Reactive Element by Chemical Vapor Deposition

小行星9801042 热障涂层（TBC）由耐应变陶瓷层和金属粘结层组成，为金属合金提供氧化保护。 在这些材料系统中观察到的主要失效模式是在暴露于氧化时粘合涂层表面与其氧化皮之间的界面区域的渐进性断裂。 用于改善粘结涂层表面处的氧化皮粘附性的一个有效途径是将一种或多种反应性元素（例如Hf或Zr）结合到通过对Ni基超合金的表面进行铝化而形成的NiAl扩散涂层中。 该补助金的结果，从最近的制造进步，在镀铝的化学气相沉积（CVD）。 与传统上用于渗铝的封闭式批量包渗和气相包渗方法相比，开放式流动CVD技术的动态性质提供了主动控制涂层基质中掺杂剂浓度和分布的希望。 以前对块体合金和金属间化合物的研究表明，为了使有益效果有效，活性元素必须以良好控制的水平和分布存在于基体材料中。 史蒂文斯理工学院与通用电气飞机发动机（GEAE）合作，正在探索与CVD掺杂概念相关的合成，表征和性能问题。 这是在NSF-GOALI概念下完成的，这是大学-工业合作研究活动长期探索的理想选择。 该研究项目有效地将Stevens在动力学实验、涂层表征和数学建模方面的优势与GEAE作为领先的航空发动机制造商的专业知识相结合，GEAE拥有独特的表征和测试设施。 材料研究部和MPS多学科活动办公室共同资助这项赠款。 %扩展先进金属材料的表面功能， 陶瓷材料已经成为高温结构应用的研究和开发的重要领域。 目前，存在通过表面涂覆和改性方法来改善“传统”结构材料（例如Ni基高温合金）的性能的强烈技术需求。 ***

9801042 Lee Thermal barrier coatings (TBCs) consist of a strain-tolerant ceramic layer and a metallic bond coat, which provides oxidation protection to metal alloys. The dominant failure mode observed in these material systems is the progressive fracture of the interface region between the bond coat surface and its oxide scale upon exposure to oxidation. One potent avenue for improving the scale adhesion at the bond coat surface is to incorporate one or more reactive elements, such as Hf or Zr, into a NiAl diffusion coating formed by aluminizing the surface of a Ni-based superalloy. This grant results from recent manufacturing advances in aluminizing by chemical vapor deposition (CVD). In contrast to the close-batch pack cementation and gas phase pack methods traditionally used for aluminizing, the dynamic nature of the open-flow CVD technique offers the promise of proactively controlling dopant concentration and distribution in the coating matrix. Previous studies with bulk alloys and intermetallics have shown that, in order for the beneficial effect to be operative, a reactive element must be present in a well-controlled level and distribution in the matrix material. Stevens Institute of Technology in collaboration with General Electric Aircraft Engines (GEAE) is exploring the synthesis, characterization, and performance issues associated with the CVD doping concept. This is accomplished under the NSF-GOALI concept, which is ideal for long-term exploration by collaborative university- industry research activities. This research project effectively integrates Stevens' strengths in conducting kinetic experiments, coating characterization, and mathematical modeling with GEAE's expertise as a leading aircraft engine manufacturer with unique characterization and test facilities. The Division of Materials Research and the MPS Office of Multidisciplinary Activities jointly fund this grant. %%% Extending the surface functionality of advanced metallic and ceramic materials has been a vital area of research and development for high temperature structural applications. Currently a strong technological need exists to improve the performance of "traditional" structural materials, such as Ni-based superalloys, via surface coating and modification approaches. ***