Microstructure characteristics and surface oxidation behaviour of SLM WC/IN718 composite

ABSTRACT

In this work, WC/Inconel 718 composite was fabricated by selective laser melting (SLM) the IN718 superalloy powders decorated with surface embedded WC powders. Also, the composite was heat-treated by a designed double-aging regime for microstructure tuning. The resulting microstructure and surface oxidation behaviour of the as-printed and the heat-treated composites were studied. The results revealed that the homogeneous microstructure was obtained, and the obvious weld beads structure with fine dendrites was detected on the surface in the SLM composite. After the double-aging heat treatment, the matrix showed a confined growth from 21.81 to 26.14 μm and the weld bead structure disappeared. XRD and EBSD analysis confirmed the formation of γ, γ′, γ′′, WC, (Nb,M)C, δ and Laves phase in the composites before and after heat-treatment. The high-density GND accommodated the strain incompatibility and the internal residual stress in different constituents. Furthermore, the underlying mechanism of oxidation behaviour was discussed.

KEYWORDS:

• Additive manufacturing
• structural composites
• heat treatment
• sintering

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (52071012), the Academic and Technical Leaders of Major Disciplines in Jiangxi Province (20182BCB22020) and Xi’an Advanced Manufacturing Technology Project (21XJZZ0048).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China [grant number 52071012]; Xi’an Advanced Manufacturing Technology Project [grant number 21XJZZ0048]; the Academic and Technical Leaders of Major Disciplines in Jiangxi Province [grant number 20182BCB22020].

Notes on contributors

Yanlin Wang

Yanlin Wang, Associate Professor, majoring in electroless deposition of alloys.

Longchao Zhuo

Longchao Zhuo, PhD, Professor, working at Xi’an University of Technology, majoring in electron microscopy analysis of alloys.

Min Liu

Min Liu, Master candidate, studying at Xi’an University of Technology, majoring in surface oxidation study of alloys.

Zhanjun An

Zhanjun An, PhD, Engineer, majoring in welding and additive manufacturing of alloys.

Chao Li

Chao Li, PhD, Engineer, Engineer, majoring in welding and additive manufacturing of alloys.

Enhuai Yin

Enhuai Yin, PhD, Engineer, majoring in welding and additive manufacturing of alloys.

Jinwen Lu

Jinwen Lu, PhD, Engineer, studying on welding and additive manufacturing of metals and alloys.

Xiufang Gong

Xiufang Gong, PhD, Professor, studying on welding and additive manufacturing of metals and alloys.