Thermochemical modelling of the phase stability of coatings deposited from the gas phase

气相沉积涂层相稳定性的热化学建模

• 批准号: 5444265
• 负责人: Professor Jochen M. Schneider, Ph.D.
• 金额: --
• 依托单位: Lehrstuhl für Werkstoffchemie (MCh)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5444265?language=en
• 关键词: Thermochemical; modelling; phase; stability; coatings

(Ti1-xAlx)N coatings are widely used for e.g. cutting toolapplications on account of their wear resistance at elevatedtemperatures. In the system (Ti1-xAlx)N, the transformationfrom the metastable cubic phase, with excellent tribologicalproperties, to the metastable hexagonal phase, with inferiorcoating properties, occurs in a range of 0,4 x 0,91, asreported by different authors. The reasons for the ratherextensive variation in the critical aluminium concentration atwhich the hexagonal phase appears are not evident.The aim of the proposed project is to contribute towardsunderstanding the reasons for this rather exensive variation.We seek to expand an existing thermochemical model, based oncomparing the Gibbs energy of stoichiometric and defect freeindividual structures to include variations in stoichiometry aswell as the presence of grain boundaries.Hence, we suggest to systematically, investigate therelationship between film stoichiometry, grain size and thestructure formed (cubic and/or hexagonal). We anticipate thatthis model will contribute significantly to a better basicunderstanding of the reasons for the above discussed differentcritical aluminium concentrations reported. In addition, such amodel will enable prediction of the coating constitution. Thiswould represent significant progress significant progress forthe production of coatings from the gas phase as compared tothe usually applied trial and error methods.

（Ti1-xAlx）N涂层由于其在高温下的耐磨性而广泛应用于切削工具。不同的作者报道，在（Ti1-xAlx）N体系中，从具有优异摩擦学性能的亚稳立方相转变为具有较差涂层性能的亚稳六方相，发生在0,4 x 0,91范围内。出现六方相的临界铝浓度变化很大的原因尚不清楚。拟议项目的目的是有助于理解这种相当昂贵的变化的原因。我们试图扩展现有的热化学模型，基于比较化学计量和缺陷自由个体结构的吉布斯能，以包括化学计量的变化以及晶界的存在。因此，我们建议系统地研究薄膜化学计量、晶粒尺寸和形成的结构（立方和/或六边形）之间的关系。我们预计该模型将有助于更好地理解上述讨论的不同临界铝浓度报告的原因。此外，该模型还可以预测涂层的组成。与通常应用的试错法相比，这将代表着从气相生产涂层的重大进步。