Additive manufacturing is a promising modern direction that allows quickly and with high accuracy layer-by-layer manufacture of complex-shaped products using a computer model from almost any metal powders. This work is devoted to the study of the influence of specimen orientation during 3-D printing and heat treatment modes on the mechanical properties of specimens made of Inconel 718 heat-resistant nickel alloy manufactured using SLM technology. In the study of the position of the specimen during printing, it was found that the strength indicators are slightly higher for vertical specimens (up to 9%), and the plasticity is lower on average by 20%. After standard heat treatment, which consists of two stages (quenching and aging) with cooling in quiet air, the strength values of vertically and horizontally constructed specimens are very close (the difference is up to 3%).The plasticity values for the horizontal position of the specimen when printing are 10% and 30% higher. According to macrogeometry, the specimens under study have cup fracture; according to microfractors, it was established that the fracture mechanism is viscous and quasi-brittle. In the initial state, which is formed by 3-D printing, there were signs of viscous fracture: the crack propagates mainly by separating the metal in planes that do not coincide with the crystallographic planes of the sections, mainly the fracture surface in the form of pits - microdepressions on the fracture surface. representing the exposed surfaces of the microvoids formed during the plastic flow of the metal. In the study of the metal of the test specimens in the polished state, it was found that specimens No. 1-5 had high integrity (low porosity), a small amount of oxide inclusions was observed. The study found that the presence of defects in the form of micropores did not lead to a significant reduction in the mechanical properties of the test samples.
