Influence of exposure algorithm of surface elements during selective laser melting on mechanical properties of synthesized material. Part 1. Short-term and long-term strength

Using the example of the heat-resistant nickel alloy VZh159, the features of the formation of the surfaces of the working part and fillet transitions during the synthesis of profiled monolithic cylindrical and flat specimens for mechanical testing by selective laser melting are considered. It has been established that the main defect of the near-surface layer is scattered gas microporosity. After heat treatment, a fine-grained layer is formed on the surface of the profiled specimens. When testing cylindrical synthesized specimens without additional surface treatment of the working part, a decrease in short-term strength characteristics at temperatures of 20, 800 and 1000 °C was found to be no more than 3, 4 and 17% respectively, as compared to polished synthesized specimens.