Abstract The aim of this study is to create a detailed process understanding regarding the tribological conditions within direct hot stamping. Hot stamping has established as a common technology for manufacturing safety-relevant components in modern car bodies. However, due to the high forming temperatures within hot stamping applications, no suitable lubricants have been developed yet. As a consequence, high friction and severe wear occur during the forming. This affects the tool wear as well as the resulting part quality. For improving the robustness and the efficiency of industrial hot stamping processes, future measures to reduce the tribological loads have to be found. The key to the development of such measures is a detailed process understanding of the tribological conditions. Within this study, friction and wear are analyzed for different workpiece and tool temperatures, relative velocities and contact pressures. Based on the experimental results, detailed knowledge of the critical cause-effect relations between process parameters and tribological behavior is acquired. The friction behavior is analyzed via strip drawing experiments under hot stamping conditions. The amount of wear is determined via confocal microscopy measurements before and after the experiments. The results of this study help to improve the process understanding of the tribological conditions within the hot stamping process and to develop future measures for reducing tool wear.

中文翻译：

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直接热冲压中摩擦学条件的表征

摘要 本研究的目的是对直接热冲压中的摩擦学条件进行详细的工艺理解。热冲压已成为制造现代汽车车身安全相关部件的常用技术。然而，由于热冲压应用中的高成型温度，尚未开发出合适的润滑剂。因此，在成型过程中会出现高摩擦和严重磨损。这会影响刀具磨损以及由此产生的零件质量。为了提高工业热冲压工艺的稳健性和效率，必须找到减少摩擦载荷的未来措施。制定此类措施的关键是对摩擦学条件的详细过程理解。在这项研究中，针对不同的工件和工具温度、相对速度和接触压力，对摩擦和磨损进行了分析。根据实验结果，详细了解工艺参数与摩擦学行为之间的关键因果关系。通过热冲压条件下的带材拉伸实验分析摩擦行为。在实验前后通过共聚焦显微镜测量确定磨损量。这项研究的结果有助于提高对热冲压过程中摩擦学条件的过程理解，并制定减少工具磨损的未来措施。获得了工艺参数和摩擦学行为之间关键因果关系的详细知识。通过热冲压条件下的带材拉伸实验分析摩擦行为。在实验前后通过共聚焦显微镜测量确定磨损量。这项研究的结果有助于提高对热冲压过程中摩擦学条件的过程理解，并制定减少工具磨损的未来措施。获得了工艺参数和摩擦学行为之间关键因果关系的详细知识。通过热冲压条件下的带材拉伸实验分析摩擦行为。在实验前后通过共聚焦显微镜测量确定磨损量。这项研究的结果有助于提高对热冲压过程中摩擦学条件的过程理解，并制定减少工具磨损的未来措施。