Tribological operational behaviour of eroded rolling contacts

 

Starting Situation

The spark erosion technology is characterized by a high geometrical accuracy. In addition, the continuous development progress in power electronics leads to an increase in the achievable erosion rates and to a minimization of the thermal influence. This makes it possible, for example, to achieve high gear quality in the manufacture of spur gears in prototype construction. In own investigations a positive process influence could be observed from the production in the form of a tripling of the number of load cycles at the pitting load capacity of wire eroded gears compared to ground gears. The causes of the increase in load-bearing capacity may be related to an improved surface structure. Due to the process-inherent formation of a cup-shaped surface structure, the formation of a lubricating film during rolling of the contact partners is favoured, which generally leads to improved application behaviour.

Research Objective

The aim of the research project is the development of a knowledge-based process model for the relationship between the process parameters in wire spark erosion and the resulting surface integrity of the machined component. On the basis of physical parameters of the discharge regime, a description model is developed, which forms the basis for the optimization of spark erosive edge zones. Based on this, the aim is to investigate the tribological application behaviour of spark eroded components experimentally in a two-disc analogy test and to calculate the tribological contact by extending the rolling strength calculation method from BR2905/47 by an alternative lubricant model.