D2: Coating of carbon fibre textile preforms to improve the infiltration properties and stability in aluminum alloys

铝基复合材料在轻质材料中的应用广为人知。但铝合金熔体具有很高的反应活性，因此，纤维与基体材料在界面上的反应以及Al4C3等金属碳化物的形成是一个主要问题。这些反应导致复合材料的机械性能和耐腐蚀性下降。ifWW和Fraunhofer IKTS的主要目标是通过化学气相沉积(CVD)为碳纤维基3D纺织品预制件开发保护涂层或涂层系统，以防止纤维和熔融金属在高温下发生反应。此外，所开发的涂层应改善涂层预制件的润湿性和渗透性能。采用TiN、Al_2O_3、碳化硅等不同材料体系进行铺层。结晶度、相组成和化学计量比不同的涂层将被沉积，以及梯度层或多层体系。表征包括检查涂层性能，如涂层厚度、涂层厚度分布、附着力、抗氧化性和机械性能。进一步的研究涉及到纤维和涂层之间的界面，以及后来涂层纤维和金属基质的界面。涂层纺织品的润湿性和耐化学性以及复合材料的机械性能将被评估。渗透将由项目合作伙伴ILK和ZMP完成。最后设计了一套连续工作的CVD设备，以获得最佳的镀膜系统。

Aluminum matrix composites are well known for applications in light-weight materials. But molten aluminum alloys are highly reactive and therefore reactions between fibre and matrix materials in the interface and formation of metal carbides as Al4C3 are a major problem. These reactions result in a degradation of the mechanical properties and corrosion resistance of the composite materials.The main aim of ifWW and Fraunhofer IKTS is the development of protective coatings or coating systems for the carbon fibre based 3D textile preforms by chemical vapor deposition (CVD) to prevent reactions between fibre and molten metal at high temperatures. Furthermore the developed layers should improve the wettability and infiltration properties of the coated preforms. Layer development will be carried out with different material systems including TiN, Al2O3 and SiC. Coatings which vary in crystallinity, phase composition and stoichiometry will be deposited as well as gradient layers or multilayer systems. Characterization comprises the examination of the layer properties like coating thickness, coating thickness distribution, adhesion, oxidation resistance and mechanical properties. Further investigations are related to the interface between fibre and coating and later to the interface of coated fibre and the metal matrix. Wettability and chemical resistance of the coated textiles and mechanical properties of the composite will be evaluated. Infiltration will be done by the project partners ILK and ZMP. Finally a continuously working CVD equipment will be designed for the best coating system.