What is Laser Peening?
Laser peening is a cold working metal surface improvement process used to impart compressive residual stresses in a wide-range of materials. Compressive residual stresses induced by laser peening prevents failures from fatigue and other surface deterioration effects by inhibiting crack initiation. Laser peening possesses precise control and the ability to access hard-to-reach areas of a component.
Laser peening can be applied to new and in-service parts. The benefits lead to an increase in service life, extended maintenance intervals, and a reduction in downtime – all without changing the design of the part. Aerospace, power generation, automotive, maritime, heavy equipment, and manufacturing industries can also focus on lightweight components while still maintaining or enhancing metal fatigue strength.
The Importance of Compressive Residual Stress
When determining fatigue strength or damage tolerance of a component, the net stress state is a summation of all existing stress states including applied and residual stresses. As a general rule, most fatigue-prone components fail when they experience high tensile stress or repeated tensile loading concentrated on the part surface. Tensile stresses exacerbate microscopic flaws in the material, pulling tiny cracks apart until they grow into large fissures. When a component is enhanced with compressive residual stresses, it can withstand greater tensile forces before cracking and failure occurs. Stronger compressive residual stresses provide a greater buffer against tensile strain, and deeper compressive stresses inhibit crack initiation and propagation below the surface.
Read more about why compressive residual stresses are key to fatigue life improvement.