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Materials Science in Additive Manufacturing Directed energy deposition

coating, which leads to larger wear debris, hindering the Acknowledgments
formation of a complete oxide layer and thereby reducing
wear resistance. 21,28 However, the wear mechanism of None.
the B-DED coating has remained relatively unchanged, Funding
consisting primarily of abrasive and oxidative wear.
This work is supported by the National Natural
Figure 11 features the wear mechanism of the coatings. Science Foundation of China (No. 52275358), Shanxi
Both coatings have high hardness due to the combined Provincial Key Research and Development Project,
effect of solid solution strengthening and microstructural China (202202050201017), Central Guidance Local
refinement. The H-DED coating has a fine microstructure Science and Technology Development Project, China
and a higher volume fraction of the eutectic structure, (YDZJSX20231A048), Doctoral Start-up Funds, Taiyuan
which results in a higher overall strength of the coating and University of Science and Technology, China (20232085),
facilitates resistance to wear. The wear rate of the H-DED and Major Scientific and Technological Special Project of
coating is about 51.86% of that of the B-DED coating.
Shanxi Province, China (202201150401019).
4. Conclusion Conflicts of interest

In this study, double-layer austenitic stainless steel coatings The authors declare that they have no known competing
were prepared on the surface of DI using both circular financial interests or personal relationships that could have
spot H-DED and B-DED. The microstructure and wear appeared to influence the work reported in this work.
resistance of the two coatings were discussed. The main
conclusions are as follows: Author contribution
(i) The microstructure of the coatings prepared by the
H-DED and B-DED processes both exhibit distinct Conceptualization: Chunjiang Zhao, Qiaofeng Bai, and
hypoeutectic alloy characteristics. The eutectic Qilong He
structure serves as a framework, providing support Formal analysis: Changyao Ouyang
to the overall coating. The eutectic structure in the Funding acquisition: Jianguo Liang
H-DED coating contains more carbon, while the Investigation: Runze Wei
B-DED coating contains less carbon. This indicates Methodology: Changyao Ouyang, Qilong He, and
that the overall strength of the B-DED coating is Xiaoyu Wu
inferior to that of the H-DED coating. Project administration: Huan Li
(ii) Due to the combined effects of solid solution Resources: Huan Li and Xuan Kang
strengthening and grain refinement strengthening, Writing – original draft: Rui Deng
the sub-surfaces of both coatings exhibit high Writing – review and editing: Yicha Zhang and Chunjiang
hardness. However, the different DED processes result Zhao
in varying degrees of microstructure refinement. The Ethics approval and consent to participate
H-DED coating, with its refined microstructure, has a
hardness that is 1.77 times that of the substrate, while Not applicable.
the hardness of the B-DED coating is 1.48 times that
of the substrate. Consent for publication
(iii) The exfoliation graphite in cast iron serves as a lubricant Not applicable.
during the wear process, effectively reducing the
coefficient of friction and enhancing wear resistance. Availability of data
However, the exfoliation cavities are prone to stress Data will be made available upon reasonable request.
concentration, which can lead to crack initiation and
propagation, causing more severe material spalling. References
(iv) During the wear process, all specimens exhibit varying
degrees of oxidative wear. The oxygen content on the 1. Wei R, Ouyang C, Wang R, et al. Effect of chromic acid
worn surface of the H-DED coating reaches 26.4 anodization on the corrosion resistance of Fe-based
alloy coatings by high-speed laser cladding. Mater Lett.
wt.%, which is 2.66 times that of DI and 2.00 times 2023;350:134887.
that of the B-DED coating. The high oxygen content
indicates a more significant amount of oxides on the doi: 10.1016/j.matlet.2023.134887
specimen surface, resulting in better lubrication and, 2. Wei R, Mao M, Liang J, et al. Repair feasibility and
consequently, higher wear resistance. performance enhancement analysis of Fe-based alloy

Volume 3 Issue 4 (2024) 10 doi: 10.36922/msam.4974