Analysis of Powder Feeding Behaviour in Coaxial Laser Cladding
Y.H. Cui, L.L. Wu, Y.C. Yang, Y.C. Lan, J.L. Lin, N.W. Fang, X.Y. Chen and R. Li
To investigate the effect of different process parameters on the powder feeding behaviour in coaxial laser cladding stainless steel powder with a fibre laser, high-speed cameras with different resolution, image analysis software and FLUENT software were employed to study the behaviour of conic powder jet stream under the nozzle. The feasibility of the method was also evaluated in detail. The obtained results show that grey level is not directly the powder distribution in the jet but rather a projection of this distribution. The powder distribution is an almost symmetrical Gaussian distribution in specific regions. As the powder feeding rate increases, the concentration of the convergence point increases; the carrier gas flow affects the gas and powder flow speed and concentration. The larger the carrier gas flow is, the greater the gas and powder flow speed are, but the concentration decreases, which is consistent with the grey image change law. The change of powder flow behaviour can be mainly attributed to the effect of gas flow rate on the movement tracks of powder particles.
Keywords: Fibre laser, high-speed camera, Gaussian distribution, carrier gas flow, powder flow behaviour, powder particle trajectory, numerical simulation, FLUENT