Laser attenuation of the focused powder streams in coaxial laser cladding

The optical attenuation of a laser beam passing through a powder stream during coaxial laser cladding has an important effect on the powder catchment efficiency for this new process. This attenuation for variations in the powder stream focus was studied both experimentally and theoretically in this article. Measurement of the laser attenuation caused by the streams was made to compare with the theoretical results. It shows that more than 50% of the laser energy could be lost in the powder stream and the focused stream gives less powder catchment than the nonfocused stream in coaxial laser cladding for 304 L stainless steel powder on mild steel with 1 kW CO2 laser radiation.