The work considers the task of synthesis of highly dispersed spherical powder granules by laser ablation method. To improve the geometry of synthesized particles and increase the process productivity, an electrostatic system for collecting ablation products was used, which allows the formed particles to leave the area of laser irradiation without being subjected to excessive exposure to a heat source. Using an external field makes particle motion predetermined, ensuring their adhesion to the electrodes. The paper shows the experimental results on the removal of ablated particles, as well as an assessment of the effectiveness of electrostatic field for accelerating particle motion.

By selective laser melting, samples were synthesized from the powder material of the AlSi10Mg alloy. All samples are made of aluminum alloy metal powder. Granulometric analysis data and particle morphology were studied to determine the suitability of the powder used in the selective laser melting. To identify structural defects, the samples were polished from the end and from the side of the building platform. Using a metallographic microscope, the porosity of samples made at a flow rate from 7.28 * 105 to 2.23 * 106 was analyzed. The geometric shape matching of the initial three-dimensional model was analyzed using the holes in the samples as an example. The results of particle size analysis, sphericity of particles of powder material, as well as metallographic analysis of samples can be used to improve the performance of parts obtained from AlSi10Mg aluminum alloy by selective laser melting.

In this work, we obtained the results of studying the effect of pore formation on the energy density deposited in the SLM process, as well as the effect of post-processing on the change in the nature of the pores. To study the porosity formed during the manufacture of parts by the SLM method, groups of primitive specimens were prepared and subjected to HIP processing. Pore formation was investigated by two methods: by optical microscopy and by weighing samples with subsequent calculations of density and porosity values. During the study of the initial samples, 4 types of pores were identified. Pore formation was investigated before and after HIP treatment. The dependence of pore formation on energy density is obtained.

No abstract

The great difficulty in synthesizing parts by selective laser melting lies in the formation of high-quality internal surfaces of workpieces. High quality is understood as the absence of defects in the form of shells, pores, partially fused powder granules, forming a rough surface. This task is especially relevant when obtaining parts by selective laser melting of aluminum alloys powders. The main problem is the great complexity or impossibility of their mechanical post-processing. Thus, in the manufacture of parts with working internal cavities used for the flow of liquids and gases, the presence of defects is completely unacceptable. In this paper, we studied the formation of defects in the internal surfaces during the process of obtaining objects by selective laser melting, in particular, the sticking of granules of powder material on the formed surface under various processing conditions. Variable parameters were scanning speed and laser radiation power. Data on the behaviour of the growth of a multilayer object depending on the variable parameters are obtained. The groups of samples of different shapes obtained under different melting conditions are considered.