Unveiling the microstructure evolution and mechanical properties in a gas tungsten arc-welded Fe–Mn–Si–Cr–Ni shape memory alloy

Fe–Mn–Si–Cr–Ni shape memory alloys (SMAs) are unique low-cost materials with shape memory properties that grant them the ability to be used in both functional and structural applications. Such SMAs are especially sought in the construction sector for the creation of new components and/or the reinforcement of damaged ones. In this study, a Fe–17Mn–5Si–10Cr–4Ni–1(V, C) wt% SMA was gas tungsten arc welded, with the objective to investigate the microstructure and mechanical performance changes occurring after welding. A comprehensive assessment of processing, microstructure and properties relationships was established combining microscopy (optical and electron), synchrotron X-ray diffraction, microhardness mapping and tensile testing including cycling assessment of the joint’s functional performance. It is shown that the present SMA has good weldability, with the joints reaching nearly 883 MPa at fracture strain of 23.6 ± 2.1%. Alongside this, several microstructure differences were encountered between the as-received and as-welded condition, including the formation of ferrite and Fe5Ni3Si2 P213 cubic precipitates amidst the fusion zone in the latter region. Graphical abstract: (Figure presented.)

Descrição

Funding Information: JGL and JPO acknowledge Fundação para a Ciência e a Tecnologia (FCT–MCTES) for its financial support via the project UID/00667/2020 (UNIDEMI). JGL acknowledges FCT – MCTES for funding the Ph.D. grant 2020.07350.BD. K. Z. acknowledges support from China Scholarship Council (CSC). The authors also acknowledge the support granted by the Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Research Chairs (CRC). Transmission electron microscopy was performed at the Canadian Centre for Electron Microscopy (also supported by NSERC and other government agencies). The authors would also like to thank re-fer AG, Switzerland, to supply the material required for the experiments. Publisher Copyright: © The Author(s) 2024.

Palavras-chave

Ceramics and Composites Materials Science (miscellaneous) General Materials Science Mechanics of Materials Mechanical Engineering Polymers and Plastics