Approach to recovery of fatigue damage for copper film by pulsed laser irradiation

Abstract

Based on pulsed laser irradiation processing, an approach to the recovery of fatigue damage was investigated by an excimer laser for copper film with thickness of 25 μm. First, optimal parameters of laser irradiation were identified by the obtained fatigue life results under different laser treatment conditions. Then, the specimens with different amounts of fatigue damage were treated by the obtained optimal laser parameters. The results showed that the copper film can show a good degree of hardening and a smooth surface feature after the specimen surface was slightly melted by the laser irradiation, which makes the residual fatigue life be extended. When fatigue damage is less than 70%, the damage can be recovered by pulsed laser irradiation treatment. The obtained residual fatigue life of specimens is about 6 times that of no laser treatment.

Keywords:

• Fatigue damage
• Recovering damage
• Pulsed laser irradiation
• Copper film

The authors also gratefully acknowledge the financial support of the National Natural Science Foundation of China (nos. 50975005, 51010006), and the Science and Technology Plan Key Project of Beijing Education Committee (no. KZ201010005003).