Development of a model for predicting the machining forces during sealing rolling of powder metallurgical components using the gear wheel as an example

 

Starting Situation

The mechanical properties of powder metallurgical (PM) gears are largely determined by the local density of the material. On the one hand, the pores reduce the load-bearing cross-section of the gearwheel. On the other hand, each pore represents a potential point of crack initiation. Powder metallurgical gears are post-compacted in the rolling process to increase the load-bearing capacity. The influence of the contact conditions on the resulting process forces is unknown. The knowledge of the process forces allows the knowledge-based design of the sealing roll process for powder metallurgical gears.

Research Objective

The aim of the research project is to model the process force in the rolling process during the post-compaction of powder metallurgical gears on the basis of a penetration calculation. Due to the density-dependent material properties of porous materials, the rolling force cannot be described on the basis of existing models.    

In order to model the rolling force for the post-compaction of powder metallurgical gears, the effect of the process input variables of the rolling process on the rolling force and thus the local elastic-plastic deformation of the workpiece must be better understood. In particular, the density-dependent     

material properties of powder metallurgical steels. Only the knowledge of the local material properties allows the determination of the process forces present in the rolling process. Knowledge of the rolling force makes it possible to match the allowance distribution of the workpiece to the tool contour and the infeed curve used, thus improving the quality of the gearing and compaction.