ISSN 2079-3537      


Scientific Visualization, 2019, volume 11, number 5, pages 26 - 34, DOI: 10.26583/sv.11.5.03

Model, calculation method and visual representation of residual stresses in laser sintering of metal powders

Authors: A.V. Koldoba1,A, Yu.A. Poveschenko2,B, M.V. Popov3,C,D, R.V. Grishaev4,E, F.Kh. Mirzade5,E, V.G. Niziev6,E

A Moscow Institute of Physics and Technology

B Keldysh Institute of Applied Mathematics RAS

C National Research Nuclear University MEPhI

D Polytech Lyon, Université Claude Bernard Lyon

E Institute on Laser and Information Technologies RAS

1 ORCID: 0000-0002-7509-4852

2 ORCID: 0000-0001-9211-9057,

3 ORCID: 0000-0002-7389-1081

4 ORCID: 0000-0003-1492-5576

5 ORCID: 0000-0003-4217-8109

6 ORCID: 0000-0003-3044-8394



One of the key problems of materials science that arises in the technology of laser deposition of powders is the prediction of residual stresses in the product, which are formed as a result of local melting of the material and its subsequent relaxation to the initial temperature, accompanied by non-uniform solidification. A method for investigation of the stress-strain characteristics both in a weld bead and in a substrate due to local heating (above the melting temperature) and subsequent solidification in laser sintering of metal powders is suggested. The model includes two-dimensional stationary equations of thermoelasticity describing the stress-strain state of a non-uniformly heated product, as well as the relations approximating the thermophysical and elastic properties of the used materials in a wide temperature range, including the phase transformation (melting). The computational algorithm developed for the numerical integration of the thermoelasticity equations is based on the support operator method. The algorithm is implemented as a code and visual presentation of the results describing the residual stresses during laser sintering of metal powders for computers with parallel architecture. The joint flat technology was used to obtain the image of the fields of scalar quantities.This was done by filling the vector quantities shown by streamlines with color and the direction field. The spatial distribution of residual thermoelastic stresses in the substrate and in the deposited layer obtained as a result of numerical simulation allows to predict the defects appearing in the product during laser deposition of powders, which depend on the laser treatment mode and on the thermophysical properties of the materials.


Keywords: Additive manufacturing, Metal microparticles, Laser sintering, Heat transfer.