Thermodynamic investigations of the diffusion-based and oxidation-based depletion mechanisms in MCrAlY coatings

MCrAlY 涂层中基于扩散和氧化的耗尽机制的热力学研究

• 批准号: 313838809
• 负责人: Professor Dr.-Ing. Christoph Leyens
• 金额: --
• 依托单位: Institut für Werkstoffwissenschaft
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/313838809?language=en
• 关键词: Thermodynamic; investigations; diffusion; based; oxidation

Already today modern gas turbine suppliers are confronted with a steadily intensifying cost pressure in the development, manufacturing and service areas due to extensive economic competition among themselves and with alternative energy sources. Increasing the inlet temperatures into the turbine or extending the service life of components are established methods to increase the efficiency and profitability of gas turbine facilities. In order to protect parts from increased risk of oxidation and corrosion components in the hot gas path of a turbine are shielded for example with MCrAlY (M= Ni and/or Co) overlay coatings. Adapting MCrAlY coatings onto the more and more versatile operation conditions of modern gas turbine facilities is a necessity to ensure maximum service life of each part and the turbine. Still today the general processing route is to adapt the chemical composition and properties on an experimental trial and error basis. This, however, is a time and cost consuming process, because every single potential system has to be validated and field tested later. Experience has shown that modern thermodynamic software packages are a powerful to predict properties and structure of materials and alloys through calculation of system related state variables and simulation of diffusion processes. At the present point in time these programs can only simulate diffusion between solid and/or liquid phases, though. A straightforward consideration of the atmospheric influence is not possible due to (commercial) unavailability of mobility databases for oxygen and relevant oxides (e.g. Al2O3, Cr2O3, Y2O3). The diffusion controlled formation and growth of an oxide scale with adjacent surface near depletion, however, is crucial for the lifetime of the coating and the whole part. The research project is dedicated to investigate the tempering related oxidation and interdiffusion processes for a well known gamma/beta MCrAlY overlay coating in conjunction with IN738LC. On the basis of this data, a simulation model shall be developed and subsequently validated through oxidation trails, long-term heat treatments (12000 h), microscopic investigations, EDX, XRD, as well as available literature data. Compared to previous studies a lifetime prediction shall be given based on identified lifetime criteria and simulation results. Presuming a successful validation of the gamma/beta MCrAlY simulation model, the application onto a chemical and microstructurally different gamma/gamm prime MCrAlY overlay system is planned in a potential fourth funding year. By doing so, the universality, reliability and adaptability of the developed model shall be analysed.

如今，现代燃气轮机供应商已经面临着由于他们之间的广泛经济竞争和替代能源而导致的开发，制造和服务领域的成本压力稳定增强。建立了提高燃气轮机设施效率和盈利能力的方法，将入口温度提高到涡轮机中或延长组件的使用寿命。为了保护涡轮机热气路径中氧化和腐蚀成分的风险增加，例如用McRaly（M = Ni和/或CO）覆盖涂层。将MCRALY涂料调整到现代燃气轮机设施的多功能操作条件上是确保每个零件和涡轮机的最大使用寿命的必要条件。如今，一般的处理途径仍是根据实验试验和误差基础调整化学成分和性能。但是，这是一个时间和成本耗尽的过程，因为每个潜在系统都必须验证并以后进行现场测试。经验表明，通过计算系统相关状态变量和扩散过程的模拟，现代热力学软件包是一种有力的可预测材料和合金结构的功能。但是，目前这些程序只能模拟固体和/或液相之间的扩散。由于（商业）对氧和相关氧化物的移动性数据库（例如AL2O3，CR2O3，Y2O3）的迁移率数据库（商业）不可用，因此无法直接考虑大气影响。然而，氧化物尺度的扩散控制的形成和生长在耗尽近乎耗尽的情况下，对涂层和整个部分的寿命至关重要。该研究项目致力于研究与IN738LC结合使用的众所周知的伽马/β覆盖层覆盖涂层的相关氧化和扩散过程。根据此数据，应通过氧化跟踪，长期热处理（12000 h），微观研究，EDX，XRD以及可用的文献数据来开发并随后通过氧化轨迹（12000 h）进行仿真模型。与以前的研究相比，应根据确定的寿命标准和仿真结果给出终生预测。假设对Gamma/beta McRaly模拟模型的成功验证，该应用程序在潜在的第四个资金年内计划在化学和微观结构上不同的伽马/伽马级Prime McRaly覆盖系统上进行应用。通过这样做，应分析开发模型的通用性，可靠性和适应性。