Microstructure and mechanical properties of double-wire feed GTA additive manufactured 308L stainless steel. Issue 9 (14th July 2020)

• Record Type: Journal Article
• Authors: Ke, Yang; Xiong, Jun
• Is Part Of: Rapid prototyping journal. Volume 26:Issue 9(2020)
• Page Start: 1503
• Page End: 1513
• Publication Date: 2020-07-14
• Subjects: Mechanical properties -- Microstructure -- GTA -- 308L stainless steel -- Double-wire feed additive manufacturing; Engineering design -- Periodicals; 620.004205
• DOI: 10.1108/RPJ-09-2019-0238
• Languages: English
• ISSNs: 1355-2546

Abstract

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.