Nickel H, Quadakkers W J, Singheiser L
Institute of Materials and Processes for Energy Systems, IWV-2, Research Centre Juelich GmbH and University of Technology Aachen, 52425 Juelich, Germany.
Anal Bioanal Chem. 2002 Oct;374(4):581-7. doi: 10.1007/s00216-001-1185-7. Epub 2001 Dec 21.
In three different examples, the effects of the oxidation behaviour as well as the microstructural stability of high temperature materials and protective coatings was determined by combining the results of kinetic studies with extensive analytical investigations using, among other techniques, SNMS, SIMS, SEM, TEM, Rutherford back scattering (RBS) as well as X-ray diffraction. 1). The effect of water vapour on the oxidation behaviour of 9% Cr steels in simulated combustion gases has been determined. The effects of O2 and H2O content on the oxidation behaviour of 9% Cr steel in the temperature range 600-800 degrees C showed that in dry oxygen a protective scale was formed with an oxidation rate controlled by diffusion in the protective scale. In the presence of water vapour, after an incubation period, the scales became non-protective as a result of a change in the oxidation limiting process. The destruction of the protective scale by water vapour does not only depend on H2O content but also on the H2O/O2-ratio. 2). The increase of component surface temperature in modern gas turbines leads to an enhanced oxidation attack of the blade coating. Improvements in corrosion resistance and longer lifetime thermal barrier coatings in gas turbines have been achieved by improvement of the high temperature properties of MCrAlY coatings by additions of minor alloying elements such as yttrium, silicon and titanium. 3). The use of oxide dispersion strengthened (ODS) alloys provides excellent creep resistance up to much higher temperatures than can be achieved with conventional wrought or cast alloys in combination with suitable high temperature oxidation/corrosion resistance. Investigation of the growth mechanisms of protective chromia and alumina scales were examined by a two-stage oxidation method with 18O tracer. The distribution of the oxygen isotopes in the oxide scale was determined by SIMS and SNMS. The results show the positive influence of a Y2O3 dispersion on the oxidation resistance of the ODS alloys and its effect on growth mechanisms.
在三个不同的实例中，通过将动力学研究结果与使用包括二次离子质谱（SNMS）、二次离子质谱（SIMS）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、卢瑟福背散射（RBS）以及X射线衍射等多种技术进行的广泛分析研究相结合，确定了高温材料和防护涂层的氧化行为以及微观结构稳定性的影响。1）. 已确定水蒸气对模拟燃烧气体中9% Cr钢氧化行为的影响。在600 - 800摄氏度温度范围内，氧气（O₂）和水蒸气（H₂O）含量对9% Cr钢氧化行为的影响表明，在干燥氧气中会形成保护性氧化皮，其氧化速率由保护性氧化皮中的扩散控制。在有水蒸气存在的情况下，经过一段孕育期后，由于氧化限制过程的改变，氧化皮变得不再具有保护性。水蒸气对保护性氧化皮的破坏不仅取决于水蒸气含量，还取决于水蒸气与氧气的比例（H₂O/O₂比）。2）. 现代燃气轮机中部件表面温度的升高导致叶片涂层的氧化侵蚀加剧。通过添加钇、硅和钛等微量合金元素来改善MCrAlY涂层的高温性能，从而提高了燃气轮机的耐腐蚀性能并延长了热障涂层的使用寿命。3）. 与传统的锻造或铸造合金相比，使用氧化物弥散强化（ODS）合金在更高温度下具有优异的抗蠕变性能，并兼具合适的高温抗氧化/耐腐蚀性能。采用¹⁸O示踪剂的两阶段氧化法研究了保护性氧化铬和氧化铝氧化皮的生长机制。通过SIMS和SNMS确定了氧化皮中氧同位素的分布。结果表明Y₂O₃弥散相对ODS合金抗氧化性能的积极影响及其对生长机制的作用。
