Effect of Laser Irradiation Parameters on Healing Fatigue Damage for Polycrystalline Copper Film

In this paper, the effect of laser parameters on fatigue life was investigated by laser irradiation for the undamaged and pre-damaged copper film specimens with thickness of 25μm. The results showed that the laser parameters have a great impact on the strengthening of original specimens and the healing of specimens with fatigue damage, and total fatigue life of the healed specimen with fatigue damage was longer than that of the strengthened original specimen. According to the obtained fatigue life results under different laser irradiation conditions, the optimal laser parameters were identified. The fracture morphology was observed by SEM. The results showed that, under the optimal laser parameters condition, a dense layer was found on the surface of specimen and the columnar grains were refined, which results in increasing the total fatigue life of the specimen.