Stressability of PM-Gears under Consideration of Local Porosity

An efficient gear design requires minimal safety margins in order to realize a full material utilization in terms of load capacity. This leads to a necessity of increasingly accurate calculation methods for the load capacity of gears. In this paper, a method for the calculation of the stressability of surface densified powder metal gears considering local material properties is presented. The approach to consider local porosity characteristics for the calculation of the gear load capacity is implemented by an image-processing tool that analyses metallographic micrographs. The stressability is calculated based on the local porosity characteristics, regarding porosity distribution and local pore morphology. Based on this, the local load capacity can be calculated by comparing the local stress profile resulting from the tooth mesh and the local stressability profile.