Rolling-assisted direct energy deposited Inconel 718: microstructural evolution and mechanical properties after optimized heat treatment

Chen Li, Peter Hodgson, Michael Preuss, Yu Chen, Xinhua Wu, Yuman Zhu, Yang Tian, Aijun Huang

Research output: Contribution to journalArticleResearchpeer-review

6 Citations (Scopus)


Post-heat treatment is a necessary and important step for additive-manufactured products to relieve residual stress and to further improve mechanical performance. In this work, the heat treatment strategy for Inconel 718 superalloy fabricated by rolling-assisted laser-directed energy deposition (L-DED) has been designed and systematically investigated for the first time. The results show that the designed homogenization heat treatment at 1080 °C for 10 min can effectively dissolve most of the detrimental Lave phases existing in the rolling-assisted L-DED samples. Meanwhile, it results in a homogenous grain structure through static recrystallization, while maintaining a similar prior-refined grain size of ∼8 µm. On this basis, a high number density of γ″ and γ′ precipitates appear in the microstructure after applying a subsequent double-aging heat treatment. The optimized microstructure through such effective post-heat treatment designed in this work has led to a significant increase in material strength at both the room and elevated temperatures while maintaining good ductility.

Original languageEnglish
Pages (from-to)118-127
Number of pages10
JournalJournal of Materials Science and Technology
Publication statusPublished - 1 May 2023


  • Additive manufacturing
  • Heat treatment
  • In-situ rolling
  • Mechanical properties
  • Nickel superalloy

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