Modeling of the selective laser melting process in additive manufacturing

Abstract

The possibilities of theoretical analysis based on numerical modeling of complex processes of additive manufacturing by selective laser melting method are viewed. Methods of high-precision modeling of the formation of a single melt bath are discussed, taking into account the geometry of the formed powder layer, the energy distribution in the spot, the effects of ray re-reflection, the vapor recoil force, the Marangoni effect and denudation mechanisms. Experimental studies on the cultivation of samples from BrX copper powder with particles of 20...50 microns in size by selective laser melting using continuous fiber laser radiation with a wavelength of 1.064 microns were carried out. In particular, all the experiments were carried out under conditions when growing conditions and modes are completely coincident with the calculated model. To assess the accuracy of the modeling system, the dimensions of the melting region and the morphology of the surface of the melt were compared. The presented computational model was used in the development of technology for growing products from copper alloy powders using selective laser melting method. Research in the field of modeling the stress-strain state in a composite material formed in the SLP process, consisting of an Ak9ch alloy matrix reinforced with titanium carbide particles, is also presented. Calculations were performed to identify the influence of shape (sphere, icosahedron, prism), size (1,0 microns; 5,0 microns; 10 microns) and mass concentration (1,0 %; 3,0 %; 5,0 %; 7,0 %; 10 %; 15 %), taking into account the presence of pores of various shapes. The results of calculations are compared with the results of experiments. Numerical models with subsequent experimental approbation of the optimal variant make it possible to significantly reduce the time spent for the development of new complex and promising additive technologies.