Evaluation of the material over-accumulation in direction changes during laser material deposition by means of a holistic model

Abstract

The modeling of the Laser Material Deposition process is a useful tool when determining the process parameter values and optimum strategies, what results in a reduction of the required experimental work as well as the trial-and-error tests. Despite the generation of straight lines and their superposition does not represent much difficulties, the necessity to generate complex geometries requires the usage of complex strategies and this involves the simultaneous interpolation of various axes of the machine. Consequently, the real velocity during the deposition process may differ from the programmed value and the resulting geometry of the clad would be different from that expected. Therefore, it is mandatory to model the influence of the velocity variation in the process stability, and thus, the resulting geometry of the part. With the aim of solving this issue, in the present research work a holistic model that evaluates the influence of the machine kinematics in the final shape of the clad is developed. Moreover, the proposed methodology considers the particle flow inside the cladding head, the heating of the powder particles due to their interaction with the laser beam, the generation of the melt pool, the addition of the filler material and the following solidification..