High-Cycle Tensile and Torsional Fatigue of AlSi10Mg Aluminum Alloy Produced by Selective Laser Alloying

The article presents the results of cyclic and static mechanical tests for tension and torsion of samples grown in different areas using selective laser melting from ASP35 aluminum powder. The results of macro- and microstructural studies of the obtained additive aluminum alloy AlSi10Mg are presented. It is shown that in the deposited aluminum alloy array there are pores of various sizes and unfused particles of aluminum powder. Specimens for torsion and tensile tests are made from grown cylindrical blanks using the mechanical processing method. For cyclic tensile tests, a corset shape of the working part of the sample is chosen due to high sensitivity of the resulting AlSi10Mg alloy to stress concentration. Torsional fatigue tests are carried out using samples with a cylindrical working part. A series of cyclic tests is carried out in tension and torsion in the region of high-cycle fatigue in the soft loading mode under a symmetric stress cycle. Tensile and torsional fatigue curves are plotted for different orientations of the grown samples. A comparison is made of the anisotropy coefficient values of mechanical properties during tensile and torsional fatigue and the anisotropy coefficients during static tensile and torsion tests. It was found that during cyclic torsion the coefficient of anisotropy of properties is greater than during static tests and cyclic tensile tests. Based on the results of cyclic tensile tests, the endurance limit of the considered aluminum alloy is determined for all directions of the specimen growth. An analysis of the fracture surfaces of the samples after cyclic tensile tests is carried out. It has been shown that cyclic durability is most influenced by defects in the form of pores and unmelted particles of aluminum powder.