Co-sintering of metal-ceramic composites with three-dimensional complex structures

金属-陶瓷复合材料具有很高的灵活性和巨大的技术应用潜力，因为它们有可能扩展性能谱，并结合不同的性能，如局部导电性和绝缘能力。更实际的是，通过分级或组合不同的延性金属部件来实现高硬度、高韧性和高损伤容限，可以对陶瓷的脆性特性产生积极的影响。尽管有这些优点，但到目前为止，这种复合材料主要是通过流延方式结合不同的箔来生产的。大批量生产具有复杂结构的部件仍然是具有挑战性的。在本项目中，将开展并系统地研究基于熔丝制造(FFF)工艺的复杂复合材料的添加制造以迎接挑战。该项目的主要目标是了解任意三维形状的金属-陶瓷复合材料在共烧过程中的变形、内应力演化和分层损伤，并开发一种可靠的数值方法来预测和优化已处于设计阶段的复合材料的应力状态。通过降低复合材料中的临界剪应力和拉应力，可以避免烧结过程中的变形和分层。利用开发的数值方法，一方面可以直接进行针对材料和工艺的部件设计优化，以避免在生产过程中出现意外缺陷。另一方面，FFF工艺有望实现具有集成智能的复杂形状部件的生产，例如，可以为金属部件提供陶瓷涂层以进行磨损保护。

Metal-ceramic composites offer high flexibility and great potential for technical applications due to the possibility they offer to extend the property spectrum and to combine divergent properties such as local electrical conductivity and insulating capability. More practically, the brittle characteristics of ceramics can be positively influenced by grading or combining different ductile metal components to achieve high hardness, toughness and damage tolerance. Despite these benefits, such composites are until now mainly produced by combining different foils by means of tape casting. The production of components with complex structures in large volume is still challenging. In this project, the additive manufacturing of the complex composites using the Fused Filament Fabrication (FFF) process will be carried out and systematically studied to face the challenge. The main objectives of the project are to understand the deformation, internal stress evolution and damage due to delamination in metal-ceramic composite components of arbitrary three-dimensional shape during the co-sintering process and to develop a reliable numerical method to predict and optimize the stress state in the composite already in the design phase. Distortion and delamination during sintering should be able to be avoided by reducing the critical shear and tensile stresses in the composite. With the developed numerical method, on the one hand, material- and process-specific optimization of the component design can be performed directly to avoid unexpected defects during production. On the other hand, the FFF process is expected to enable the production of complex shaped components with integrated intelligence, e.g., metallic components can be provided with a ceramic coating for wear protection.