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(如硬度和耐磨性)的应用。这些特性在成分复杂性和材料去除率方面限制了材料的可加工性。因此，在陶瓷制造技术中，已经开发出网状策略来批量生产复杂的部件，而定制的部件通常通过毛坯的绿色加工来生产。然而，为了达到高精度，必须在烧结后对这些部件进行最终加工。电火花加工允许对定制的陶瓷部件进行精密加工，前提是材料具有导电性。然而，电火花加工已经成为金属加工的标准工艺，对于陶瓷来说，人们对它的了解还不够充分。在提出的项目中，研究了氧化物基陶瓷和碳化物弥散陶瓷两种材料体系。这项研究的目的是阐明从陶瓷的组成和微结构结构可以推断出陶瓷的电火花可加工性、表面特性和块体特性的程度。系统地研究了材料成分的变化及其与电火花加工参数的相互作用。为此，材料在加工过程之前和之后进行了深入的表征，明确地关注由于电火花过程与材料表面的相互作用而产生的过程区域。对加工数据进行补充记录。在该多维参数空间中找到的相关性被用作模型的输入数据。其目的是了解材料的去除机制，并阐明基于模型的电火花加工过程的描述，该描述不仅可以定量地预测电火花加工的可加工性，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将提供给行业、陶瓷和机床制造商以及最终用户，用于为特定应用量身定做的陶瓷材料的开发以及电火花加工技术的系统设计。它代表着在机床中实施标准化陶瓷专用技术数据库的一个里程碑，并将是电火花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电火花可加工陶瓷领域和电火花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.