FOR 5380: Functional surfaces through adiabatic high-speed processes: Microstructure, mechanisms and model development - FUNDAM³ENT

高速冲裁（HSB）代表了传统切割工艺（如普通切割、精细切割或激光切割）的一种经济和环保的替代方案。特别是对于高强度和超高强度钢，以及轻金属，HSB在产生可直接用作功能表面的冲切表面方面具有巨大的潜力，而无需进一步的机械，热或热化学后处理步骤。这是因为在HSB中，根据材料和工艺参数，可以形成绝热剪切带（ASB），然后在其中发生材料分离。所得到的冲裁表面的特征在于高硬度、低边缘压痕和低粗糙度，并且几乎没有毛刺。然而，到目前为止，有一个缺乏基本的了解，导致在HSB ASB的形成机制。然而，这反过来又是必不可少的，以便能够专门利用所描述的特殊表面特性。因此，FUNDAM <$ENT研究小组致力于在跨学科网络中研究影响HSB中ASB形成的材料和工艺相关因素。研究小组的总体目标是开发一个基于材料科学和工艺技术的模型，尽可能全面地描述HSB中剪切带的形成，即针对不同材料和广泛的工艺参数。这将通过汇集材料科学、材料工程和生产工程领域的专业知识来实现。研究小组要解决的重要研究问题包括，例如，各种微观结构成分和变形历史对剪切带形成趋势的影响，或者ASB是否也可以在具有良好导热性的材料中产生的问题，例如铝。还正在进行研究以确定HSB过程中的应变速率在多大程度上决定剪切带的微观结构、几何形状和性质，以及材料的熔化或再结晶温度是否影响ASB的形成和所得微观结构。在不同应变速率范围内对HSB（10²-10 μ s/cm 2）进行的大量实验一方面可以获得全面的工艺知识，另一方面也是正确理解剪切带中微观结构效应的基础。这是支持在微观结构和工艺水平的多尺度模拟方法。借助于对HSB在摩擦学、腐蚀性和循环机械载荷下产生的表面的材料行为的系统研究，可以检查冲裁过程、微观结构和冲裁表面的所得性能之间的关系。

High-speed blanking (HSB) represents an economically and ecologically interesting alternative to conventional cutting processes such as normal, fine or laser cutting. Especially for high-strength and ultra-high-strength steels, but also for light metals, HSB holds great potential with regard to the generation of blanked surfaces that can be used directly as functional surfaces without further mechanical, thermal or thermochemical post-processing steps. This is due to the fact that in HSB, depending on the material and the process parameters, adiabatic shear bands (ASB) can form, in which material separation then takes place. The resulting blanked surfaces are characterized by high hardness, low edge indentation and low roughness, and exhibit almost no burr. To date, however, there is a lack of fundamental understanding of the mechanisms leading to the formation of ASB in HSB. This in turn, however, is essential in order to be able to specifically harness the exceptional surface properties described. The FUNDAM³ENT research group is therefore dedicated to researching the material- and process-related factors influencing the formation of ASB in HSB in an interdisciplinary network.The overall objective of the research group is to develop a model based on materials science and process technology that describes shear band formation in HSB as comprehensively as possible, i.e. for different materials and in a wide range of process parameters. This is to be achieved by pooling expertise from the fields of materials science, materials engineering and production engineering. Important research questions to be addressed by the research group include, for example, the influence of various microstructural constituents and the deformation history on the tendency to shear band formation, or the question of whether ASB can also be produced in materials with good thermal conductivity, such as aluminum. Research is also being conducted to determine the extent to which the strain rate in the HSB process determines the microstructure, geometry and properties of the shear bands and whether the melting or recrystallization temperature of a material influences ASB formation and the resulting microstructure. Extensive experiments in different strain rate ranges of HSB (10²–10⁵ s⁻¹) generate a comprehensive process knowledge on the one hand and are the basis for a sound understanding of the microstructural effects occurring in the shear band on the other hand. This is supported by multi-scale simulation methods at the microstructural and process level. With the aid of systematic investigations of the material behavior of surfaces produced by HSB under tribological, corrosive and cyclic mechanical loading, an examination of the relationships between the blanking process, the microstructure and the resulting properties of the blanked surface is made possible.