2005 Conference on Lasers and Electro-Optics Europe

BEAM ATTENUATION IN THE LASER CLADDING PROCESS

J. C. Alvarez, J. M. Amado, G. Rodriguez, M. J. Tobar, A. Yaflez

Departamento de Ingenieria Industrial I, Universidade da Coruina,Escuela Politecnica Superior, Mendi-abal s/n, E-15403, Ferrol,

Tfno: 981337400, Fax: 981337410, e-mail: ayanez(@udc.es

In the laser cladding processes a powder is placed on the surface of the workpiece and heated beyond the melting pointby the beam. The laser produces the fusion of the base material and the powder particles producing, during the coolingprocess, a layer with a chemical composition close to the fed material. The obtention of such composition requires theright process parameters to minimize dilution, defined as the part of the base material in the coat. These treatments canbe done essentially in two ways: A powder is preplaced in the surface and after that melted by the laser beam or acontinuous flow of powder is sent, carried by a gas, to the surface of the workpiece and at the same time the meltingprocess takes place. The theoretical modelling of the second one requires the simulation of the propagation of theenergy delivered by the beam to the inner parts of the processed material and the continuous powder feeding whichproduces changes in geometry and composition of the treated material [1, 2]. This powder, which is forming a wholewith the base material after the cladding process finishes, has to be taken into account before its arrival to the basematerial. This work wants to compute these effects which are basically the heating of the fed material when flyingunder the laser beam and the decreasing of the beam power due to such heating. There are Publisher Works followingthis line [3], but the one presented here computes the case of the very common TEMOI. transversal mode at least in thehigh power C02 sources.

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Figure 1.- Schematic view of the process.

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Figure 2.- Temperature ofpowder particles.

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Figure 3.- Beam power arriving the base material.

1. M. Picasso, A.F.A. Hoadley, nt J. Numer. Meth. Heat Fluid Flow Vol.4(1994)61-83.2. J. Mazumder, P. S. Mohanty, Int. J. Mater. Proc. Technol., Vol. 11 (3/4) (1996) 193-251.3. Y. Fu et al, Int. J. Mater. Proc. Technol., Vol. 128 (2002) 106-112.

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