Laser treatment for corrosion prevention

Abstract

The laser surface treatment is applied to a multilayer component (copper alloy plated with two thin coatings, nickel and gold). The aim of the study is to melt the whole gold layer (thick < 1 jim) without damaging the underlying layers. The gold melting must be homogeneous and the process must be fast to avoid heat diffusion in the depth. For these reasons, the laser has been chosen for surface treatment.The application of this laser surface treatment is to improve the corrosion resistance of electrical contacts due to columnar microstructure of gold deposited by electrolytic process. Tests of corrosion are carried out in the humid synthetic air containing low contents of pollutants (NO2, SO2 and Cl2).An numerical study has been realized to find the best laser conditions to melt the whole gold layer.

Fabrication of black aluminium thin films by magnetron sputtering

“…Technique (4) is not universal because it requires that the deposition occurs on preprocessed silicon substrates. The surface of BMs prepared by techniques (1)-( 4) can be easily modied by a localized nanosecond laser treatment that produces a glossy metal surface 27,28 and enables the additional tuning of its functional properties. Technique (5) employs mostly femtosecond lasers 10 and is time consuming, which is its major drawback.…”

Effect of pulsed laser parameters on the corrosion limitation for electric connector coatings

“…The corrosion germs are much smaller than in the untreated area. As detailed in a previous study [7], it is shown that the laser treatment improved the corrosion resistance by reducing the size of the germs. As a general rule, the best results are obtained for a number of pulses ranging from one to five and laser treatment is more efficient on polished samples.…”