Analytical model of the catchment efficiency in high speed laser cladding

Today laser cladding is a well known technique for the generation of functional layers and/or regeneration of parts. In comparison to alternative processes like thermal spraying and overlay welding laser cladding has some disadvantages. The processing time of laser cladding is comparably high and the catchment efficiency can be low. These facts can make the laser cladding process expensive. However it is possible to decrease the overall processing time and to increase simultaneously the efficiency for laser cladding. In this study a model is described which evaluates the catchment efficiency with respect to the melt pool geometry. The paper takes two effects into account The primary effect is given by the particles diving directly into the melt pool. The secondary effect is given by the amount of powder particles molten in the laser beam during the time of flight and pointing at the surface beside the melt pool. A comparison between the experiment and the model shows a sound agreement. (C) 2009 Elsevier B.V. All rights reserved.