A new wire arc additive manufacturing (WAAM) process combined with gravity-driven powder feeding was developed to fabricate components of tungsten carbide (WC)-reinforced iron matrix composites. The purpose of this study was to investigate the particle transportation mechanism during deposition and determine the effects of WC particle size on the microstructure and properties of the so-fabricated component.
Thin-walled samples were deposited by the new WAAM using two WC particles of different sizes. A series of in-depth investigations were conducted to reveal the differences in the macro morphology, microstructure, tensile performance and wear properties.
The results showed that inward convection and gravity were the main factors affecting WC transportation in the molten pool. Large WC particles have higher ability than small particles to penetrate into the molten pool and survive severe dissolution. Small WC particles were more likely to be completely dissolved around the top surface, forming a thicker region of reticulate (Fe, W)6C. Large WC particles can slow down the inward convection more, thereby leading to an increase in width and a decrease in the layer height of the weld bead. The mechanical properties and wear resistance significantly increased owing to reinforcement. Comparatively, samples with large WC particles showed inferior tensile properties owing to their higher susceptibility to cracks.
Fabricating metal matrix composites through the WAAM process is a novel concept that still requires further investigation. Apart from the self-designed gravity-driven powder feeding, the unique aspects of this study also include the revelation of the particle transportation mechanism of WC particles during deposition.
This work was supported by the National Natural Science Foundation of China (Grant No. 51975270), the Scientific Research Foundation of Hunan Provincial Education Department, China (Grant No. 21A0257) and the Natural Science Foundation of Hunan Province, China (Grant No. 2019JJ40245).
Credit authorship contribution statement: Runyao Yu: Investigation, Formal analysis, Visualization, Software, Writing – original draft, Writing – review and editing. Xingwang Bai: Supervision, Project administration, Data curation, Writing – original draft, Writing – review and editing. Xueqi Yu: Investigation, Formal analysis, Visualization. Haiou Zhang: Supervision, Project administration.
Declaration of competing interest: The authors report no declarations of interest.
Data availability: The raw/processed data required to reproduce these findings cannot be shared at this time, as the data also form part of an ongoing study.
Yu, R., Bai, X., Yu, X. and Zhang, H. (2022), "WC-reinforced iron matrix composites fabricated by wire arc additive manufacturing combined with gravity-driven powder feeding: particle transportation and size effects", Rapid Prototyping Journal, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/RPJ-09-2022-0312
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