Авіаційно-космічна техніка та технологія (Jun 2020)
INVESTIGATION OF MECHANICAL PROPERTIES AND STRUCTURE OF IN718 ALLOY PRODUCED BY 3D-PRINTING
Abstract
The subject of research – the process of structure formation and improvement of mechanical properties of high-resistant alloys obtained by 3D-printing. The purpose of work – control the level of mechanical properties of high-resistant alloys obtained by 3D-printing for the manufacture of parts of aircraft gas turbine engines. Objectives – experimental determination of mechanical properties of heat-resistant nickel alloy IN718 obtained by selective laser sintering of LPW and Sino Euro powders both in the horizontal XY and in the vertical Z direction; a comparative analysis of the mechanical properties of IN718 and ЭП718-ВД(ИД) (ХН45МВТЮБР) alloys according to ASM 5662M and TU 14-1-3905-85; a study of the structure of samples of IN718 alloy before and after heat treatment. Research methods – when summarizing and analyzing scientific and technical literature in the direction of studying mechanical properties and forming the structure of heat-resistant nickel alloys obtained by the method of selective laser sintering, an integrated approach was used; processing and analysis of experimental data on determining the mechanical properties of the IN718 alloy in the three-dimensional direction (horizontal direction XY and vertical direction Z); metallographic studies of samples of the IN718 alloy made by 3D-printing were carried out before and after heat treatment. The results obtained - by comparing the mechanical properties of the heat-resistant alloy IN718 obtained by 3D printing from powders LPW and Sino Euro with the normative characteristics ASM 5662M (for alloy IN718) and TU 14-1-3905-85 (for alloy ЭП718-ВД) it was found that for vertical samples (grown in the Z direction) a certain decrease in the strength characteristics and an increase in plastic characteristics compared with the values of horizontal samples (grown in the XY direction), and in terms of impact strength, the IN718 alloy exceeds the norm in the researched temperature range 3.75 times. Scientific novelty – the dependence of the structural characteristics and mechanical properties of the IN718 alloy on the direction of part growth has been established and it has been shown that after heat treatment it is possible to obtain a dense, uniform microstructure characterized by a fine-grained structure with micro grains that are elongated in the direction of sample growth.
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