Development of PVD-coated cutting tools made of natural rocks

为了减少对原材料的依赖和碳化钨等传统刀具材料的生产对环境的负面影响，有必要扩大刀具材料的范围。自然形成的石头在这里提供了潜力。为了扩大这些切割材料的可用性，并使之能够与高速钢相媲美，使用技术上的PVD涂层是有前景的。在选择了基本上适合用作切割材料和PVD涂层的石材后，使用机械和化学涂层预处理工艺对其进行处理。研究了这些前处理工艺对亚表面的影响，以及对涂层性能和涂层附着力的影响。有了这样的理解，就有可能确定适用于石材的涂层系统。根据涂层的残余应力和涂层形貌，探讨了涂层结合的机理。最后，用涂层石材刀具对Al7075进行了车削加工，并通过磨损分析对涂层失效机理进行了表征。该项目的独创性特点是通过应用PVD技术提高性能，扩大了石制工具的应用可能性。

In order to reduce the dependency on raw materials and the negative environmental influences caused by the production of conventional cutting materials such as tungsten carbide, it is necessary to expand the range of cutting materials. Naturally occurring stones offer potential here. In order to expand the usability of these cutting materials and to enable comparable applications to HSS, there is the perspective of using a technical PVD coating. After a selection of stones that are fundamentally suitable for use as a cutting material as well as for the PVD coating, these are processed using mechanical and chemical coating preconditioning processes. The influence of these preconditioning processes on the subsurface as well as on the coatability and layer adhesion is investigated. With the help of this understanding it is then possible to determine suitable coating systems for stones. The mechanisms of coating adhesion are investigated on the basis of residual stress and coating morphology. Finally, coated stone tools are used for the turning of Al7075 and the coating failure mechanisms are characterised by means of a wear analysis. The originality of the project is characterised by the expansion of the application possibilities of tools made of stone by means of performance-enhancing application of PVD technology.