Self-lubricating HPPMS-CrAlN-coatings for the use in dry cold forging processes of steel

冷锻的成形制造工艺由于在生产技术中的高材料利用率和相关的能源和资源效率而非常重要。为了使冷锻过程可控，使用液体和固体润滑剂，由于生态，经济和立法原因，这往往是值得怀疑的。因此，干法成型具有更大的研究潜力。成形中干式摩擦系统润滑剂的放弃导致要求的增加。这些要求是由合适的表面结构与自润滑涂层相结合来控制的，基于现有技术，对结构化工件表面与自润滑涂层相结合的摩擦学性能的描述还不够深入。因此，我们面临的挑战是探索一种工件减摩表面结构和工具耐磨自润滑涂层的组合，这是第一次在冷锻中实现干式成形。该项目的目的是生成一个模型，以解释工件形貌和自润滑涂层之间的摩擦学相互作用。理想的模型应该解释物理，热和化学机制的低碳钢材料的干燥成形的经验关系和解析公式，其中涉及摩擦和磨损。在第一步中，将使用HPPMS（高功率脉冲磁控溅射）工艺制备和表征新型自润滑涂层。进一步的研究重点是减少摩擦的随机表面结构的发展，以减少真正的接触面积。在随后的组合物中，将研究新开发的HPPMS涂层和结构化工件表面之间的相互作用。受迫害的假设是，它存在一个摩擦学系统，其特征在于特殊的工具涂层系统与定义的工件结构相结合，从而减少摩擦和磨损。因此，干式成型可靠且经济可行。

Forming manufacturing processes of cold forging are of great importance due to the high material utilization and the associated energy and resource efficiency in the production technology. In order to make cold forging processes controllable, liquid and solid lubricants are used, which are often questionable due to ecological, economic and legislative reasons. For this reasons, dry forming exhibits an increased research potential. Abdication of lubricants for dry tribological systems in forming leads to an increase of requirements. These requirements are controlled by suitable surface structures in combination with a self-lubricating coating.The description of the tribological properties using structured workpiece surfaces in combination with a self-lubricating coating based on the current state of the art are insufficiently explored. Therefore, the challenge is to explore a combination of friction-reducing surface structures on the workpieces and a wear resistant, self-lubricating coating on tools, which allows dry forming in cold forging for the first time.The aim of this project is the generation of a model in order to explain the tribological interaction between the workpiece topography and a self-lubricating coating. The aspired model should explain the physical, thermal and chemical mechanisms of dry forming of mild steel materials by empirical relationships and analytical formulations, which involve friction and wear. In a first step, the preparation and characterization of a novel self-lubricating coating using HPPMS (High Power Pulsed Magnetron Sputtering) process will be carried out. A further research focus is the development of a friction-reducing stochastic surface structure in order to reduce the true contact area. In a subsequent composition, the interaction between the newly developed HPPMS coating and structured workpiece surface will be studied. The persecuted hypothesis is, that it exists a tribological system, which is characterized by a special tool coating system in combination with a defined workpiece structure, so that friction and wear are reduced. Dry forming is then reliably and economically feasible.