Section - Nanocomposites and nanomaterials 

Optimal filling of a given volume with spherical and non-spherical powders for additive manufacturing 
Duriagina Z.A.1, Pankratov A.V. 2, Romanova T.E.2
1 Lviv Polytechnic National University, Department of Applied Materials Science and Materials Engineering Ukraine, Bandera street, 12, Lviv-79013, Ukraine,. 
E-mail: zduriagina@ukr.net
2 Department of Mathematical Modeling and Optimal Design, Institute for Mechanical Engineering Problems of the National Academy of Sciences of Ukraine, Pozharskogo, 2/10, Kharkiv-61046, Ukraine

Modern laser 3D printers can work with various materials, including metal powders [1]. Among them, powders of titanium alloys are considered most promising for the aerospace industry due to the unique combination of high structural strength, low density and high corrosion resistance [2]. In order to obtain a qualitative product, it is necessary to optimize the parameters of the technological process for producing powders of titanium alloys to achieve the highest possible degree of homogeneity of powder particals and eliminate defects on the surfaces.
The article presents the results of studying the partical-size composition of VT20 titanium alloy spherical and nonspherical powders. A allowable size range of fractions (160 ... 200 microns) is set to minimize defects during the layer-by-layer buildup process on a laser 3D printer. Micromechanical properties of these layers are studied. Two algorithms for optimizing the packing of titanium powder particles (spherical and non-spherical) are proposed, with the algorithm depending on particle-size composition and the phi-function technique [3] used. Results of numerical experiments are given.

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3.	Stoyan, Yu., Pankratov, A., Romanova, T., Chugay, A. Optimized object packings using quasi-phi-functions// In G. Fasano and J.Pintér (ed.), Optimized Packings and Their Applications. Springer Optimization and its Applications 105, New York. – 2015. – P. 265-291.