Residual Stress Measurements in Metals

Residual stresses are known to influence a material’s mechanical properties such as fatigue life. Sometimes, the effect on properties is beneficial; other times, the effect is very deleterious. Therefore, it is important to be able to monitor and control the residual stress level, and where necessary, relieving stress in metals.

Residual Stress Measurements

One technique for measuring residual stress is the sin² ψ method, which is used to measure stress in fine-grained polycrystalline materials. The method relies on the measurable shift of a high-angle diffraction peak as the sample is rotated through a tilt angle ψ. Variations of the method also allow us to determine the principal stresses and the presence of shear stresses.

Among the many applications for this method are:

  • Axles, wheels, bolts, clamps, etc.
  • Cemented carbides
  • Composites
  • Ground/machined surfaces
  • Heat treated metals
  • Plated surfaces and thin films
  • Shrink fitted components
  • Tube surfaces
  • Weldments
  • Fasteners and springs

Residual Stress Measurements in Metals