Investigation of the interactions of incremental surface layer forming and HPPMS coating on fine blanking dies in order to enable a load-applied surface integrity adjustment (TEStOI)

在汽车工业中用于生产刹车片载体等功能部件的高强度钣金材料的精冲加工中，与传统钣金材料相比，刀具负荷增加。机械表面层成形的增量方法，如深滚加工，适合通过增加耐磨性来延长刀具寿命。机械表面处理用于提高动态加载零件的表面完整性。OI包括显微组织、硬度分布、残余应力、表面形貌和刀具表层损伤。为了进一步减少磨料和粘合剂的磨损，工具的功能表面通过物理气相沉积（PVD）进行涂层。使用基于知识的工艺设计，可以选择性地影响涂层的OI。此外，涂层的特定OI对刀具表层的OI和复合附着力有积极影响。而涂层沉积过程中的热应力和精落料过程中面层的循环弹性机械应力可使刀具表层的残余应力和微观组织依次松弛。在OI的热稳定性和弹性稳定性方面，相应的物理因果关系大多是未知的。一方面，涂层过程中的热量输入如何改变工具的OI以及涂层的OI与工具中逐渐设置的OI之间发生了什么相互作用尚不清楚。另一方面，落料过程中循环弹力载荷对刀面层OI的影响尚不清楚。因此，该项目基于这样的研究假设，即通过增加表面层转变和PVD涂层设定的OI可以设计为在基底温度T < 300°C的低温涂层过程中在摩擦引起的热载荷和随后的循环机械载荷下保持稳定。研究了刀具表层OI的热稳定性和弹性稳定性，以及PVD涂层OI的影响。一方面，专门调整刀具表层的OI，然后利用高性能等离子体工艺对刀具表面进行涂层处理。另一方面，对刀具表层和涂层进行了研究，以分析生产工艺的影响，并得出合适的工艺参数组合。为了扩展研究结果，在数值模拟中检查了OI的行为。

In the processing of high-strength sheet metal materials for the production of functional components such as brake pad carriers in the automotive industry by means of fine blanking the tool load increases compared to conventional sheet metal materials. Incremental methods for the mechanical surface layer forming, such as deep rolling, are suitable for increasing the tool lifetime by increasing the wear resistance. Mechanical surface treatment is used to improve the surface integrity (OI) of dynamically loaded parts. The OI includes microstructure, hardness profile, residual stresses, surface topography and damage of the tool surface layer. In order to further reduce abrasive and adhesive wear, the functional surfaces of the tools are coated by means of physical vapour deposition (PVD). Using a knowledge-based process design, it is possible to influence the OI of the coating selectively. A specific OI of the coating furthermore has a positive effect on the OI of the tool surface layer and the compound adhesion. In particular, the residual stress and the microstructure of the tool surface layer, however, can be successively relaxed by the thermal stress during the coating deposition as well as under cyclic elasto-mechanical stress of the surface layer during the fine blanking process. The corresponding physical cause-effect relationships with regard to the thermal and elastic stability of the OI are mostly unknown. On the one hand, it is unclear how the heat input during the coating process alters the OI of the tool and what interactions occur between the OI of the coating and the incrementally set OI in the tool. On the other hand, it is unknown how the cyclic elasto-mechanical load during the blanking process affects the OI of the tool surface layer. Therefore, the project is based on the research hypothesis that the OI which has been set by means of incremental surface layer transformation and PVD coating can be designed to be stable in a low-temperature coating process at substrate temperatures T < 300 °C under a friction-induced thermal and subsequent cyclic mechanical load. The thermal and elastic stability of the OI of the tool surface layer as well as the influence of the OI of the PVD coatings are investigated. On the one hand, the OI of the tool surface layer is specifically adjusted and then the tool surface is coated by means of a high-performance plasma process. On the other hand, investigations of the tool surface layer and coatings are carried out in order to analyze the influences of the production processes and to derive a suitable combination of process parameters. In order to expand the findings, the behaviour of the OI is examined in a numerical simulation.