Test laboratory for residual stress analysis at the University of Kassel

For several years now, the Institute of Materials Engineering/Metallic Materials has been carrying out analyses for project partners from worldwide industry as part of the Center for Surface Analysis and Technology (ZerTech). This includes the analysis of all metallic and many other crystalline materials using various methods. Throughout Germany, the testing laboratory is thus the third largest of its kind. Since July 2017, ZerTech has now been accredited by the Deutsche Akkreditierungsstelle GmbH as a testing laboratory for residual stress analyses.  For many industrial companies, this is a prerequisite for joint projects in research and development.

Residual stresses are internal stresses in materials. They occur as a result of manufacturing without external stresses acting, for example when the surface of a workpiece cools faster than the core. They are invisible to the eye, but they can affect the durability of a component. Residual stress analyses are therefore an important step in the development of safe components and help prevent accidents.

"When it comes to residual stresses, as in many areas of life, the following applies: small cause, big effect," is how Dr. Wolfgang Zinn, head of ZerTech, describes it. Even small errors or adjustments in the manufacturing process of components can lead to significant changes in the residual stress state and thus ultimately have devastating effects on the safety and reliability of machines, for example when a gear suddenly fails.

Research into the causes and effects of residual stresses is carried out in the laboratories of the Institute of Materials Engineering. To be able to measure them reliably - as a prerequisite - new methods and evaluation routines for residual stress analysis have been developed in recent years together with research partners, using X-rays for example. New scientific questions are also constantly being derived from test orders from industry.