How Sentenso improves the fatigue strength of components

The residual stress in surfaces is a decisive factor for the fatigue strength of shot-peened components. A new measuring method and a fast and mobile X-ray diffractometer can significantly reduce the time required to develop and validate shot peening processes.

Nowadays, a large number of components are shot peened in a wide range of industries. Shot-peened components significantly improve the fatigue strength and therefore the service life of dynamically loaded components. However, checking them is very time-consuming and is therefore not usually integrated into the production process. With the usual measuring methods, none of the quality parameters provide direct information about the expected fatigue strength of the finished component. This must be determined by time-consuming test series.

The deformation of the metallic crystal lattice of the component provides information about the fatigue strength. The  changed distance between the lattice lines can be measured using X-rays and the principle of interference. All radiographic methods for determining residual stress utilise this principle and determine the distances in the crystal lattice using the Bragg equation. A new X-ray diffractometer based on the cos-alpha method can shorten and simplify this previously time-consuming measurement. The optical system significantly reduces the radiation energy and enables a light, small, portable and very fast X-ray diffractometer, which is therefore much easier to use for on-site and field measurements. Typical individual measurements can be completed with the device in under a minute.