Core Competence
Surface Integrity


An unexpected failure of a gear can lead to high costs or legal consequences. To eliminate the risk of premature failure or to do damage assessment the gear needs to be characterized. For highly loaded gears the analysis of gear macro geometry is often insufficient.

During contact between two gears high stresses occur in the near surface zone of the gear flanks as well as in the roots of the gears. If the stresses exceed the load carrying capacity the gears will fail. The load carrying capacity directly correlates with surface integrity, which describes the condition of the surface, the composition and the internal stress state of the microstructure. To evaluate the running behavior of gears the surface integrity has to be known. Along the manufacturing chain different mechanical, thermal and chemicals loads influence the surface integrity. On the one site those loads cannot be measured in-situ up until now and on the other site the interactions are not known. That is why it is particular important to check the surface integrity of the gear after manufacturing.

At WZL it is possible to carry out almost all state of the art test and measuring methods. Besides near manufacturing tests and measurements such as roughness measurement, barkhausen noise measurement or nital etching , WZL features a fully equipped laboratory. At this laboratory your gears can be fully analyzed by the means of scanning electron microscopy, micro sections, hardness profiles, residual stress profiles and much more. Alternatively a lot of these measurements can although be performed at your facility with mobile measuring equipment. In addition to the full characterization of your gears our experts will help you to interpret the results. We can help you to identify potential in optimization of the surface integrity our your gears. This is possible by technological knowledge of the manufacturing processes on the one side and the knowledge about the interaction between surface integrity and the running behavior of gears on the other side. These competences are combined in the WZL Gear Group.

Our goal: Customized solutions
- Knowledge about the surface integrity of your gear
- Detection of potential sources of error along your manufacturing chain
- Optimization of surface integrity of your parts


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