Intégration des spécificités d'une configuration coaxiale multifaisceaux pour la maîtrise du procédé de fabrication additive laser-fil

The Wire Laser Additive Manufacturing (WLAM) process can produce near-net-shape parts by depositing matter from a wire melted locally by a laser. While managing the wire feeding direction relative to the tool path can prove challenging, the use of coaxial configurations reduces this problem by placing the power input along the wire axis. This can be achieved by an annular beam or by combining several beams, but leads to an increased sensitivity of the power distribution to the head position relative to the part. However, the manufacturing parameters, especially power density, are linked to defect formation during production.Process control can therefore be improved by looking at the specific features of a coaxial configuration with multiple beams on the power distributions and produced geometries.To this end, the three-beam experimental set-up is presented in detail, before studying the process behaviour during bead and part production.A realistic modelling of the power distribution is proposed to represent the multiple beams and is used to simulate the power densities on the wire and on the bead.By studying the interaction between the beams and the wire, a model is proposed to predict defect formation depending on the distance between the head and the part.An effect of the head orientation to the part is also observed on power densities and bead geometries.These results illustrate specific behaviours of the coaxial configuration with multiple beams and indicate that the head position and orientation relative to the part are essential in controlling the process.