A review of the effects of laser peening on creep properties

Laser peening (LP) is a critical surface modification technique widely applied in automotive, energy, defense, and aerospace industries to enhance material durability, such as fatigue life and wear/corrosion resistance. This process induces substantial compressive residual stresses (CRS) deep into the material through high strain rate plastic deformation, thereby enhancing the material’s resistance to surface-related failures and extending the lifespan of engineered components. In addition to generated CRS, the microstructural transformations induced by LP, such as high-density dislocations, sub-grain boundary (SGB) formation, and grain refinement, play a vital role in this enhancement. In particular, LP results in dislocation tangles (DTs) and dense dislocation walls (DDWs), eventually transforming into SGBs. This sequence contributes to obstructing dislocation movements which, depending on the process and material, can remain stable at high temperatures, thereby improve creep resistance. Microstructure modification can enhance performance in applications subjected to prolonged high temperatures and stresses, especially in mitigating of the effects of the creep. This review paper investigates the impact of LP on creep behavior, emphasizing the role of induced CRS, dislocation structures, and the formation of SGBs on improving creep resistance. The study addresses the challenges associated with LP, particularly the need for future research on optimizing the controlling of dislocation movement deep within material at extreme conditions.