Eliminating intermetallic compounds via Ni interlayer during friction stir welding of dissimilar Mg/Al alloys

Journal of Materials Research and Technology

Chuansong Wu¹  Sachin Kumar² 

[1] Department of Mechanical Engineering, Indian Institute of Science (IISc), Bengaluru, Karnataka, 560012, India;MOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, China;

关键词: Friction stir welding;    Aluminum alloy;    Magnesium alloy;    Ni interlayer;    Mechanical properties;    Microstructure;   

DOI  :  

来源: DOAJ

【 摘 要 】

There is a substantial demand in transportation industries to join dissimilar Al and Mg alloy to reduce the structural weight further. However, it is challenging to produce high-strength joints of Al/Mg even with friction stir welding due to the formation of intermetallic compounds (IMCs). In a quest to suppress/eliminate the IMCs, we propose to add a Ni interlayer in a sandwich form between the Mg and Al plates. Widely used and industrially applicable AA6061-T6 and AZ31B Mg alloys are taken for experimentation in the present study. The Ni interlayer's effects on microstructure, mechanical properties, and IMCs characterization are studied. The Ni interlayer can drastically cease the molecular diffusion of Mg and Al across their interfaces, and typical IMCs Al3Mg2 and Al12Mg17 are eliminated. Significant dispersion of Ni with Al and Mg is found in the weld zone, which forms Al3Ni and Mg2Ni compounds. The energy-dispersive X-ray spectroscopy confirms the efficacy of Ni addition to wipe out the β and γ IMCs phases. The localized fracture analysis of Ni interlayered joint suggests dual-mode failure, i.e., ductile and brittle. The mechanical testing advocates better weld quality for Ni interlayered joints compared to its conventional ones.

【 授权许可】

Unknown