Mathematical Methods of Observation of Wave Processes During Deformation of 3D Technology Products

Abstract

The purpose of this work is to develop and apply mathematical methods (Fourier interpolation) to fix the presence and evaluation of the mechanisms of wave processes developing in products made of powder stainless and heat-resistant alloys of additive technologies (SLM) during their deformation.Methods. To fix the presence of wave processes of plastic deformation in loaded 3d technology products, samples of powder stainless steel 03X18H12M2 (analog AISI 316L) and powder heat-resistant alloy 08ХN53BMTU (analog Inconel 718), manufactured using SLM technology on a 3d printer SLM280 2.0HL, were used. The samples were subjected to uniaxial stretching (GOST 1497-84) with a constant rate of capture in air at room temperature. The lengths of the marked sections were measured using digital video recording of the loading process of the marked surface of the samples. Graphs of the dependences of local relative deformation along the length of the sample and at selected test moments were constructed. The mathematical substantiation of the existence of the wave character of the fixed functions as periodic was carried out by decomposing them into a Fourier series with subsequent interpolation.Results. It has been experimentally established that in the volume of the studied samples of powder stainless steel type 316L and heat-resistant alloy type Inconel 718, obtained by SLM technology, when they are stretched, there is a multistage character of wave deformation reflecting the development and movement of local micro-volumes of increased plasticity (foci of localized deformation). The Fourier interpolation procedure of a complex of experimentally obtained piecewise linear functions of the dimensions of the marking grid and their local deformations confirmed their apparent periodicity, i.e. the presence of a wave character.Conclusion. The developed technique of fixing and mathematical processing of wave deformation spectra can be used to analyze the changing parameters of the surface marking (rolling grid) of 3d products both along their length and at fixed loading times, as well as when constructing multidimensional dependencies of the marking parameters on the geometry of samples and test time.