Laser peening is a surface enhancement technique used to improve the mechanical properties of materials, particularly metals. It involves the use of high-energy laser pulses to generate shockwaves on the surface of a material. These shockwaves induce compressive residual stresses in the material, providing enhanced strength and fatigue resistance.
The process of laser peening typically involves the following steps:
Laser pulse generation: High-energy laser pulses are generated, usually using lasers like Nd:YAG (neodymium-doped yttrium aluminum garnet) or fiber lasers.
Focusing: The laser beam is focused onto the material's surface, creating a plasma plume.
Shockwave generation: The intense energy of the laser pulse vaporizes a thin layer of material, creating a rapidly expanding plasma. The plasma generates shockwaves that travel into the material.
Residual stress induction: The shockwaves induce compressive residual stresses in the material as they propagate through it. This is particularly beneficial for metals, as compressive stresses can improve fatigue life and resistance to crack initiation.
Laser peening is utilized in various industries, including aerospace, automotive, and manufacturing, to enhance the durability and performance of critical components. It is effective in preventing or retarding fatigue cracks, corrosion, and other forms of material degradation. The compressive stresses induced by laser peening can also improve resistance to stress corrosion cracking and increase the service life of components subjected to cyclic loading.