Effect of a Surface Element Exposure Algorithm for Selective Laser Melting on the Mechanical Properties of the Synthesized Material: I. Short- and Long-Term Strength

Using a VZh159 superalloy as an example, we consider the formation of the surfaces of the gage portion and the fillet transitions during the selective laser melting synthesis of profiled monolithic cylindrical and flat specimens for mechanical tests. The main defect in the near-surface layer is found to be scattered gas microporosity. After heat treatment, a fine-grained layer forms at the surface of the profiled specimens. When cylindrical synthesized specimens without additional processing of the gage portion surface are tested, their short-term strength characteristics at temperatures of 20, 800, and 1000°C are found to decrease by no more than 3, 4, and 17%, respectively, compared to polished synthesized specimens.