This work is focused on the design of a 250W high-intensity continuous-wave fibre optic laser with a 15μm spot size
beam and a beam parameter product (BPP) of 1.8 for its use on
Laser-assisted Cold Spray process (LCS) in the
The metal-powder deposition process LCS, is a novel method based on Cold Spray technique (CS) assisted by laser
technology. The LCS accelerates metal powders by the use of a
high-pressure gas in order to achieve flash welding
of particles over substrate. In LCS, the critical velocity of impact is lower with respect with CS while the powder
particle is heated before the deposition by a laser beam. Furthermore, LCS does not heat the powder to achieve high
temperatures as it happens in plasma processes. This property puts aside cooling problems which normally happen in
sintered processes with high oxygen/nitrogen concentration levels.
LCS will be used not only in deposition of thin layers. After careful design, proof of concept, experimental data, and
prototype development, it should be feasible to perform micro-machining precise work with the use of the highintensity
fibre laser presented in this work, and selective deposition of particles, in a similar way to the well-known
Direct Metal Laser Sintering process (DMLS).
The fibre laser consists on a large-mode area,
Yb3+-doped, semi-diffraction limited, 25-m fibre laser cavity,
operating in continuous wave regime. The fibre shows an arguably high slope-efficiency with no signs of roll-over.
The measured M2 value is 1.8 and doping concentration of 15000ppm. It was made with a slight modification of the
traditional MCVD technique. A full optical characterization will be presented.