Advanced Processing of MCrAlY Coatings (AMPC)

新一代的燃气涡轮机发动机正努力提高其工作温度，以在发动机循环中产生更高的效率。因此，必须使用改进的热障涂层（TBC）来保护暴露于这些高温的金属部件。这些涂层由沉积在金属粘合层（粘合涂层）上的隔热陶瓷层组成。粘合涂层有两个基本作用：它增加绝缘陶瓷层和待保护部件之间的粘附力，同时提供高温下发生氧化的保护。该项目旨在开发一种改进的粘结层，以提高热障涂层的性能和耐久性，同时降低制造成本。 在本项目中，HVAF沉积工艺将用于优化粘结层的结构和粗糙度，同时优化其抗氧化性。HVAF（高速空气燃料）工艺是一种金属粉末热喷涂工艺，可高效沉积致密和弱氧化涂层，而无需昂贵的真空系统。该项目的重要挑战之一是确定是否有可能在充分限制粉末在空气中的反应以避免在沉积物中形成有害相的同时产生致密层。拟议的研究战略分为三个阶段。第一种方法将计算机流体动力学（CFD）建模与改进的诊断方法相结合，以优化和控制HVAF过程。第二步是使用一整套先进的电子显微镜技术对沉积的粘结涂层进行超细显微结构表征。在第三步骤中，通过改变HVAF工艺的沉积参数以及起始金属粉末的性质和组成来优化沉积涂层的抗氧化性和耐久性。 优化的涂层具有提高发动机燃油效率、减少温室气体排放、降低发动机制造和维护成本的潜力。

New generations of gas turbine engines are striving to increase their operating temperature to yield greater efficiency in the engine cycle. Consequently, improved thermal barrier coatings (TBCs) must be used to protect metallic components exposed to these high temperatures. These coatings consist of a thermally insulating ceramic layer deposited on a metal bond layer (bondcoat). The bondcoat has two essential roles: it increases the adhesion between the insulating ceramic layer and the parts to be protected while providing protection against oxidation occurring at high temperature. This project aims to develop an improved bondcoat layer to increase the performance and durability of TBCs while reducing the manufacturing costs. In this project, the HVAF deposition process will be used to optimize the structure and roughness of the bondcoat layers while optimizing their resistance to oxidation. The HVAF (High-Velocity Air-Fuel) process is a thermal spray process for metallic powders which enables efficient deposition of dense and weakly oxidized coatings without the need for expensive vacuum systems. One of the important challenges of the project is to establish whether it is possible to produce dense layers while sufficiently limiting the reaction of the powders in air to avoid the formation of detrimental phases in the deposits. The proposed research strategy is structured into three stages. The first combines computer fluid dynamics (CFD) modeling with improved diagnostic methods to optimize and control of the HVAF process. The second step deals with the ultrafine microstructure characterization of the deposited bondcoat layers using a complete set of advanced electron microscopy techniques. In a third step, the oxidation resistance and the durability of the deposited coatings are optimized by varying the deposition parameters of the HVAF process and the properties and composition of the starting metal powders. Optimized coatings have the potential to improve engine fuel efficiency, reduce greenhouse gas emissions, and reduce engine manufacturing and maintenance costs.