Effect of Heat Treatment on Microstructure Evolution and Mechanical Properties of Selective Laser Melted Inconel 718 Alloy

  • Qiang ZhangEmail author
  • Pan Ren
  • Xiaohui Tu
  • Yuhong Dai
  • Xiaojian Wang
  • Wei Li


The microstructure characteristics of the selective laser melted Inconel 718 alloy under as-deposited, homogenization + solution + aging (HSA) and solution + aging (SA) conditions were studied. The anisotropy and heterogeneity of mechanical properties under different conditions were also investigated. Under the as-deposited condition, the morphology and size of the grains are heterogeneous. The dendrite structures which grow nearly perpendicular to the molten pool traces, accompanying interdendritic Laves phase, can be observed within the grains. The dendrite structure completely disappeared, and the Laves phases embedded in the interdendritic regions also dissolved into the matrix to precipitate γ′ and γ″ phases after heat treatments. Fully recrystallized grains were obtained under the HSA condition, while only incomplete recrystallized grains were obtained under the SA condition. However, the characteristics of γ′ and γ″ phases are very similar under the HSA and SA conditions. Significant improvement in strength after heat treatments was due to the dissolution of undesirable Laves phase and the precipitation of γ′ and γ″ phases. For all the three conditions, different tensile properties were observed depending on the orientation of the specimens. The scatter of mechanical properties is notable, and heat treatments increased the scatter of mechanical properties.


Inconel 718 alloy mechanical properties microstructure selective laser melting 



This work was supported by Supported by National Key R&D Program of China (2017YFB0305100) and Fundamental Research Funds for the Central Universities (Grant No. 21618325).


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© ASM International 2019

Authors and Affiliations

  1. 1.Institute of Advanced Wear and Corrosion Resistance and Functional MaterialsJinan UniversityGuangzhouPeople’s Republic of China
  2. 2.Shenzhen Sunshine Laser and Electronics Technology Co., Ltd.ShenzhenPeople’s Republic of China

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