Optimization of tribological systems by aimed anticipation of the running-in by final machining on the example of journal bearings

研究项目的目的是开发径向轴承的最终加工工艺，并通过分析所产生的工件亚表层、表面形貌和磨合行为来优化其加工工艺。以42CrMo4轴颈为例，对其加工过程进行了研究。除了青铜轴承的精加工外，孔侧还检测了钢(100Cr6，42CrMo4)和铝外壳材料的高强度材料。因此，切割工艺能够有针对性地产生纳米晶亚表层，这导致在接下来的操作中产生限定的短期磨合行为。在第二个资助期，人们对纳米晶材料内部的表面层状态有了更深入的了解，从而导致摩擦系统的进一步改进。此外，正在分析将研究工作转移到内部切割过程中。由此，可以对轴颈和轴承的几何形状以及亚表层状态进行摩擦学优化。此外，还创建了一个实用的工具，用于对最终加工进行有效的过程管理，并集成了不同比例的仿真模型。轴承的制造和设计知识最终在摩擦学试验台上得到验证。为了评估模拟给出的结果，有必要在带有滑动轴承的试验台上进行实验工作。对摩擦学行为的研究尤其是在轴承磨合和混合润滑条件下进行的。实验工作的另一个方面是车削工艺的发展，该工艺必须产生可重复形成的纳米晶亚表层和优化的表面形貌。通过摩擦学实验考察了工艺参数对内切削过程的适应性，以进一步改善摩擦学性能。此外，还通过实验模拟了摩擦学接触过程中的过程理解。因此，在不同的长度尺度上考察了摩擦过程。通过WBK对最终加工进行模拟，可以获得有关接触的两个物体的初始特性的信息。这些结果以及IAM-ZBS的模拟结果确定了有限元模拟所使用的值，该值显示了滑动轴承运行过程中的地形发展及其对摩擦的影响。

Aim of the research project is the development of a final machining process for journal bearings and its optimization by analyzing the resulting work piece subsurface layer, topography and the running-in behavior. The cutting process is investigated on the example of shaft journals (42CrMo4). Besides the finishing of journal bearing made of bronze, also high-strength materials made of steel (100Cr6, 42CrMo4) and aluminum housing material are examined on the bore-side. Hereby, the cutting process enables the aimed generation of nanocrystalline subsurface layers, which lead to a defined, short running-in behavior in the following operation. This leads to the formation of the third body with low friction and wear rates.In the second funding period a deeper understanding of the surface layer states within the nanocrystalline material is generated, thus leading to a further improvement of the tribosystem. Furthermore, the transfer of the research work onto an internal cutting process is being analyzed. Hereby, the geometries as well as the subsurface layer states of the journal shafts and bearings can be tribologically optimized. Furthermore, a practical tool for an efficient process management for the final machining is being created and the simulation models at different scales are integrated. The knowledge resulting from manufacturing and design of the bearings is finally validated in the tribological test rig.To assess the results given by simulation, experimental work on a test bench with journal bearings is necessary. Study of the tribological behavior has especially got to take place during the running-in of the bearings and in the regime of mixed lubrication. Another aspect of experimental work is the development of the turning process, which has to yield a reproducible formation of a nanocrystalline subsurface layer and an optimized topography. The adaption of process parameters to the internal cutting process is examined by tribological experiments to further improve tribological behavior.In addition to the experiments simulation is used to engage process understanding during tribological contact. The friction process is therefore examined on different length scales. Simulation of the final machining by WBK yields information on initial properties of the two bodies in contact. Those results as well as the results of the simulation by IAM-ZBS define the values used by the finite element simulation that shows the topography development during the operation of the journal bearing and its influence on the friction.