TP1: Wear, corrosion and fatigue behaviour of functional surfaces produced by high-speed blanking

根据材料和所选工艺参数的不同，高速冲裁(HSB)产生的表面可能包含绝热剪切带(ASB)。这些都是均匀的区域，在微观结构上与基础材料明显分开，与周围的材料相比，它们的性能曲线发生了显著的变化，例如更高的硬度。然而，到目前为止，高速冲裁表面的结构-性能关系在很大程度上还没有得到探索。因此，子项目1的重点是为HSB表面在摩擦学、腐蚀性和循环机械载荷下的行为这一问题提供科学合理的答案。这直接关系到需要从根本上了解工作中的机理，从而确定工艺-显微结构-性能关系。这样做的前提是解释磨损、腐蚀和疲劳试验的结果，该试验是与研究小组合作伙伴一起进行的，旨在揭示HSB表面特性、工艺参数和所产生的微观结构之间的相关性。摩擦学研究包括代表不同载荷状态的各种磨损试验。因此，系统地研究了平板和曲面HSB表面在有和没有中间介质的开槽、滑动和滚动载荷作用下的材料行为。腐蚀行为的表征是在不同尺度上进行的。一方面，宏观行为是在浸泡和盐雾试验中确定的。另一方面，利用微腐蚀电池对ASB及其周围材料的单个微观结构成分的耐蚀性进行了对比评估。此外，通过特殊设计的试件几何形状，研究了在宽应变速率范围内(10？-10⁵S？)产生的ASB的疲劳性能。此外，还利用X射线衍射仪测量了HSB表面的残余应力，以评价材料的性能。用这种方法确定的宏观和微观残余应力一方面用于解释摩擦学、腐蚀和循环力学试验的结果，另一方面它们是项目合作伙伴组织建模或工艺模拟的重要评估和验证变量。子项目1中的研究成果是评估HSB表面使用性能和实际适用性的基础。通过与其他子项目的反馈，结果还可以直接影响HSB工艺的设计，从而有针对性地调整功能表面的性质。

Depending on the material and the selected process parameters, surfaces produced by high-speed blanking (HSB) can contain adiabatic shear bands (ASB). These are homogeneous zones, which are clearly delimited from the base material in microstructural terms and exhibit a significantly changed property profile compared to the surrounding material, such as a higher hardness. However, the structure-property relationships of high speed-blanked surfaces have remained largely unexplored to date. The focus of subproject 1 is therefore to provide a scientifically sound answer to the question of how HSB surfaces behave under tribological, corrosive and cyclic mechanical loading. This is directly linked to the need to gain a fundamental understanding of the mechanisms at work and thus the identification of process-microstructure-property relationships. A prerequisite for this is the interpretation of the results of the wear, corrosion and fatigue tests, which is carried out in coordination with the research group partners and aims at revealing correlations between the HSB surface properties, the process parameters and the resulting microstructure. The tribological investigations include various wear tests that represent different loading regimes. Thus, the material behavior of both flat and curved HSB surfaces is systematically investigated under grooving, sliding and rolling loads with and without intermediate media. The characterization of the corrosion behavior is performed across scales. On the one hand, the macroscopic behavior is determined in immersion and salt spray tests. On the other hand, the corrosion resistance of individual microstructural constituents of the ASB and the surrounding material is comparatively evaluated using a microcorrosion cell. Furthermore, by means of specially designed specimen geometries, the fatigue properties of ASB generated in a wide strain rate range (10²–10⁵ s-¹) are investigated. In addition, the residual stresses of HSB surfaces are measured by X-ray diffraction (XRD) to evaluate the material behavior. The macro- and micro residual stresses determined in this way are used on the one hand to interpret the results of the tribological, corrosive and cyclic mechanical tests, and on the other hand they represent important evaluation and validation variables for microstructure modeling or process simulation by the project partners.The research results obtained in subproject 1 are the basis for the evaluation of the service properties and thus the practical suitability of HSB surfaces. By means of feedback with the other subprojects, the results also enable direct influence on the design of the HSB process and thus targeted adjustment of the properties of the functional surface.