Editors: | F. Kongoli, A. G. Mamalis, K. Hokamoto |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2018 |
Pages: | 352 pages |
ISBN: | 978-1-987820-88-1 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
The possibility of products of complex shape with a fine-mesh structure, manufactured by the method of selective laser melting (SLM) of powders, initiated active scientific and practical investigations in the choice of geometric models, technological modes of melting, and available materials that make it possible to produce strong and lightweight structures [1, 2]. Damping elements manufactured by the SLM from metal powders, in view of their possible application in machine building and the space industry, are of particular interest. It is believed that the integrity of the products is ensured by the geometric parameters of structural support elements whose angular slopes are chosen like oriented bonds in the crystal lattice of diamond [3], and the strength of the material is obtained by the SLM and works in the product under compression conditions [4].
The main objective is to determine the mechanisms of plastic deformation and destruction of the structural support elements in the form of tie plates operating under compression in the dissipative object (a fine-mesh model of the clip). On the EOSINT M270 unit, with a laser power of 200 W and a scanning speed of 800 mm / s, a series of clips was made using the method of selective laser melting of 316L steel powder. The tests revealed a mechanical response of the metal plate, which is characteristic for materials with an auxetic property, in which, due to the anharmonicity of the interatomic bonds, elastic counteraction to the applied deforming load occurs. It was established that the discontinuities in the continuity of the material were accompanied by local reversals of the microvolumes with the formation of oppositely curved lens-like bundles and bridges between the deformation nature. Thus, the orientation and extent of melt volumes, as well as the elastoplastic accommodation of their boundaries, are the determining structural factors for the manifestation of the auxetic effect and the growth of elastic moduli.