X-ray diffraction has become the industry standard for residual stress characterization of automotive components. It is an essential tool for process optimization, design improvements, and failure analysis.
The fatigue life of a component is often enhanced by cold-working processes such as shot peening. XRD residual stress measurement can be used to verify that these locations have been enhanced to the specified residual stress level.
Aggressive or abusive machining can create regions of tensile stress that can make certain areas of a component susceptible to crack initiation and increase the rate of crack propagation.
Residual stress measurement can be used to verify that finite element models are predicting the correct residual stress in a component. When these models are deficient, the known residual stress can be used to improve them.
When issues of fatigue cracking are considered, potentially harmful tensile residual stresses, alone or in combination with stress concentrations, can lead to fatigue crack initiation and propagation.
Heat treatment processes are commonly applied to automotive components to lower or reduce the residual stresses present. Residual stress measurement can be used to ensure that such processes have been correctly applied and that any harmful residual stresses have been reduced to an acceptable level.
Tensile residual stresses created during the welding process can lead to cracking. Components can be measured before welding, after welding, and after post-welding processes have been applied to ensure that stresses are properly managed.
Proto MG15 mini goniometer measuring residual stress inside a 60 mm diameter automotive engine cylinder bore
Residual stress map of a brake rotor surface using a Proto LXRD laboratory residual stress mapping system
