Numerical simulation of the inelastic behavior of a structurally graded material

Abstract

Additive manufacturing is considered to be a very promising technology when it comes to the manufacture of metal products of a complex shape for various applications, since it provides designs with improved mechanical properties. Another advantage of modern solutions for additive manufacturing is that they help manufacturers to control the in-process structure formation of final products. Of special interest is the feasibility of simultaneously creating local regions with preferred microstructures and properties. This paper discusses the effect of the process parameters of selective laser melting (SLM) on the structure and properties of Inconel 718 specimens. The results of uniaxial tension experiments on homogeneous specimens, as well as on structurally graded specimens with equiaxed fine grains and elongated coarse grains, are presented. The authors also proposed a finite-element approach to modeling of mechanical properties. The input data include experimental data describing tensile specimens manufactured using two different process regimes of SLM to obtain different types of microstructure (equiaxed fine-grained and coarse columnar-grained), as well as experimental data on tensile tests of the composite specimen. The proposed approach defines the spatial distribution of material properties in homogeneous and structurally graded specimens. This paper presents the results of modeling based on the proposed approach for the inelastic behavior of structurally graded specimens as compared to the experimental data.