The primary benefit of the Metal Improvement Company laser peening
process is the development of a deep layer of compressive stress
with only minimal cold working. This will increase the component's
resistance to failure mechanisms such as fatigue, fretting fatigue and
stress corrosion. A secondary benefit is the reduced potential for thermal
relaxation of the residual stresses, because of the reduced cold work that is
associated with the laser peening process.
Concept of Stress Intensity Superposition
Superposition of compressive residual stresses onto the tensile stresses generated during cyclic fatigue. Crack propagation is suppressed if the net stresses remain in the compressive state. | 
