Microstructure and mechanical properties of double-wire feed GTA additive manufactured 308L stainless steel
ISSN: 1355-2546
Article publication date: 14 July 2020
Issue publication date: 29 September 2020
Abstract
Purpose
This paper aims to introduce a novel concept of a double-wire feed (DWF) to alleviate heat accumulation and improve the cooling rate of the molten pool in gas tungsten arc (GTA)-based additive manufacturing (AM), in which the former wire is fed into the arc and the latter wire is melt by the molten pool.
Design/methodology/approach
The microstructure, phase composition and mechanical properties of 308 L stainless steel components built by single-wire feed (SWF) AM and DWF-AM are compared, and the differences are analyzed in detail.
Findings
The microstructures for both wire feeding modes include δ and γ phases. Compared with the SWF-AM, the sample fabricated in the DWF-AM exhibits finer microstructure, and the microstructure in the middle region is transformed from columnar grains to cellular grains. Microhardness of the sample produced in the DWF-AM is higher than the SWF-AM. In comparison to the SWF-AM, the tensile strength of the specimen fabricated using the DWF-AM reaches 571 MPa and increases by 16.14%.
Originality/value
This study proposes a novel concept of the DWF-AM to reduce heat accumulation as well as enhance the cooling rate of the molten pool, and improved mechanical properties of the 308 L stainless steel component are obtained.
Keywords
Acknowledgements
This work was funded by National Natural Science Foundation of China, No. 51975491 and No. 61573293, Sichuan Science and Technology Program, No. 2019YFG0354, and the Fundamental Research Funds for the Central Universities, No. 2682019CX12.
Citation
Ke, Y. and Xiong, J. (2020), "Microstructure and mechanical properties of double-wire feed GTA additive manufactured 308L stainless steel", Rapid Prototyping Journal, Vol. 26 No. 9, pp. 1503-1513. https://doi.org/10.1108/RPJ-09-2019-0238
Publisher
:Emerald Publishing Limited
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