Heterogeneities of microstructure and mechanical properties for inconel 718 strut tensile sample fabricated by selective laser melting

Abstract

The heterogeneous microstructure and mechanical properties of the strut tensile sample were investigated in this paper. A novel strut tensile sample of Inconel 718 was designed and fabricated based on selective laser melting (SLM). The standard tensile samples were fabricated horizontally and vertically comparing with strut tensile samples. The results exhibit that mean elasticity modulus and nanohardness of eutectic-free area, which are 167 GPa and 5.89 GPa, respectively, which is higher and more homogeneous than the other three areas. Mechanical properties of the strut were determined on a bond tester, elastic modulus(E), yield strength (YS), and ultimate tensile strength (UTS) of the strut sample are 149 ± 16.6 GPa, 691 ± 30.1 MPa, and 1017 ± 24.5 MPa, respectively. The standard deviation of elastic modulus and yield strength obtained by using strut tensile sample are higher than that of standard tensile specimen. The main error sources of the novel tensile test using strut are the measurement of displacement and the diameter of strut tensile sample.

Keywords

• Additive manufacturing
• Mechanical properties testing
• Microstructure
• Anisotropy
• Nickel alloys