Fundamental material based investigations to understand electric discharge machinability of electrically conductive ceramics with oxide matrix

结构陶瓷被用于工程和医疗技术等需要良好机械性能的领域，如硬度和耐磨性。这些特性限制了材料在零件复杂性和材料去除率方面的可加工性。因此，在陶瓷制造技术中，净形策略已经发展到批量生产复杂部件，而定制部件通常是通过毛坯的绿色加工来生产的。然而，为了实现高精度，必须在烧结后对这些部件进行最终加工。电火花加工允许精密加工定制陶瓷部件，只要材料是导电的。然而，电火花加工已成为金属加工的标准工艺，但在陶瓷加工中却没有得到充分的了解。本课题主要研究了氧化基陶瓷和碳化物分散陶瓷两种材料体系。该研究的目的是阐明在多大程度上可以从陶瓷的组成和微观结构中推断出ED的可加工性、表面性能和体积性能。系统地改变了材料的组成，并研究了它们与电火花加工参数的相互作用。为此，在加工过程前后对材料进行深度表征，并明确关注由ED工艺与材料表面相互作用产生的工艺区域。补充加工数据的记录。在这个多维参数空间中发现的相关性被用作模型的输入数据。目的是了解材料去除机制，并阐明基于模型的ed过程描述，这不仅可以定量预测ed可加工性，而且还可以为所研究的材料设计一套设计和加工指南。所获得的广泛的基础知识提供给行业，陶瓷和机床制造商以及最终用户，用于开发适合特定应用的陶瓷材料以及ED加工技术的系统设计。它代表了标准化陶瓷专用技术数据库在机床上实现的一个里程碑，将是ED可加工陶瓷材料广泛应用的关键。为此，该提案整合了两个项目合作伙伴在ED可加工陶瓷和ED加工领域的知识和经验。

Structural ceramics are used in applications in e.g. Engineering and Medical technology requiring good mechanical properties such as hardness and wear resistance. These properties restrict the machinability of the materials in terms of component complexity and material removal rate. In manufacturing technology of ceramics, net-shape strategies have therefore been developed to mass produce complex components while customized parts are typically produced by green machining of blanks. However for high precision a final machining of these components after sintering is necessary. Electric discharge machining allows for precision machining of customized ceramic components provided that the material is electrically conductive. Yet the EDM process which has become a standard process in machining of metals is not sufficiently understood in case of ceramics. In the project proposed, two material systems of ceramics with oxide matrix and carbide dispersion are investigated. The aim of the study is to elucidate in how far the ED machinability, surface properties and bulk properties of the ceramics can be deduced from their composition and microstructural architecture. Compositions of materials are systematically varied and their interaction with ED machining parameters is studied. For this purpose materials are characterized in depth before and after the machining process with a clear focus on the process zones created by the interaction of the ED process with the material surface. Complementary the machining data are recorded. The correlations found in this multidimensional parameter space are used as input data for a model. The aim is to understand the material removal mechanisms and to enunciate a model-based description of the ED-process which not only allows to quantitatively predict ED-machinability but also to devise a set of design and machining guidelines for the materials investigated. The acquired broad basic knowledge is provided to the industry, ceramics and tooling machine manufacturers as well as end users, for the development of ceramic materials tailored for specific applications as well as for a systematic design of ED machining technologies. It represents a milestone for the Implementation of standardized ceramic-specific technology databases in the tooling machines and will be the key to a widespread application of ED machinable ceramic materials. For this purpose the proposal consolidates the knowledge and experience of both project partners in the field of ED machinable ceramics and in ED machining.