Investigation on the Surface Properties of 5A12 Aluminum Alloy after Nd: YAG Laser Cleaning

The surface of the aluminum alloy is prone to oxidation, which in turn affects the quality of the weld. The 5A12 aluminum alloy was cleaned by acousto-optic Q-switched diode-pumped Nd:YAG laser and the effects of different laser powers and different cleaning speeds on the surface roughness, microstructure, element content, microhardness, residual stress and corrosion resistance of aluminum alloy were investigated. The results show that when the power is 98W and the cleaning speed is 4.1 mm/s, the effect of Nd: YAG laser on the removal of oxide film on 5A12 aluminum alloy surface is the most effective. After laser cleaning, the smoothness and strength of aluminum alloy surface can be effectively improved. However, as a major element in 5A12 aluminum alloy, the content of magnesium decreased. At the same time, the residual tensile stress was generated on the surface of the aluminum alloy after cleaning, and the corrosion resistance slightly decreased.

Online Measurement of Internal Parameters in a Quasi-CW Diode-Pumped Nd:YAG Laser

We present a simple and practical online measurement method to estimate internal parameters (small-signal gain coefficient, internal optical losses, the saturation parameter, and transmittance of the coupling output mirror) in an neodymium doped yttrium aluminum garnet Nd:YAG laser system. A measurement cell, placed in the optical cavity of a laser, consists of a polarizer and a rotatable polarization analyzer. Internal parameters are measured conveniently by introducing variable polarization reflective loss. Online measurements of the internal parameters in a quasi-continuous-wave (CW) diode-pumped Nd:YAG laser are performed and the measured results, which are discussed and analyzed, indicate good measurement accuracy. Experiments to investigate validity are conducted and further verify the applicability of the measurement method. A measurement cell with a small volume that is easy to access has potential to be used in the online measurement, optimized design, and maintenance of a laser.

Compact diode-pumped Nd:YAG laser for remote analysis of low-alloy steels by laser-induced breakdown spectroscopy

A low weight diode-pumped Nd:YAG laser (400 g, 1064 nm, 5 ns, 130 mJ per pulse) was developed for a compact laser-induced breakdown spectroscopy (LIBS) system to be installed on a robotized arm.